Dissertations / Theses: 'SPR'

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Gombau, Roigé Jordi. "Influencia de las semillas de la uva y de la suplementación con taninos enológicos comerciales sobre el color y la astringencia del vino tinto; aplicación de la resonancia de plasmones superficiales al estudio de las interacciones tanino-mucina." Doctoral thesis, Universitat Rovira i Virgili, 2020. http://hdl.handle.net/10803/670913.

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Els tanins del vi negre són determinants de la seva qualitat ja que exerceixen una gran influència sobre el color, l'astringència, el cos, la seva capacitat per a l'envelliment i en general la textura del vi. De forma tradicional els tanins del vi procedeixen de forma natural de les baies, alliberant-se de les llavors i les pells durant la vinificació, o bé de la criança o de la suplementació amb tanins comercials. Al capítol 1 d'aquesta tesi s'estudia la relació entre la morfologia de la baia i el color, la composició en tanins i la astringència dels vins negres de quatre varietats: Merlot, Cabernet Sauvignon, Ull de llebre i Garnatxa. La principal conclusió d'aquest treball va ser que el percentatge en pes de les llavors respecte del pes de la baia és un factor determinant de la concentració en tanins i la astringència del vi. Al capítol 2 de la present tesi s'estudia l'efecte com copigmentos dels tanins enològics i es conclou que tots els tanins enològics estudiats són eficaços com copigmentos. Així mateix es proposa un índex per mesurar l'eficàcia dels diferents tanins comercials. Al capítol 3 de la present tesi s'estudia la interacció entre 3 tipus de tanins i la mucina mitjançant ressonància de plasmons superficials (SPR). Per a això es van determinar les constants cinètiques i termodinàmica de la interacció així com l'índex d'astringència dels diferents tanins. Les constants de dissociació termodinàmica i cinètica de les interaccions tanins-mucina van presentar els coeficients de correlació més alts amb l'índex de astringència. Aquestes dades suggereixen que la percepció d'astringència no solament depèn de l'estabilitat termodinàmica del complex taní- proteïna sinó també probablement del temps que triga aquest complex en dissociar-se.
Los taninos del vino tinto son determinantes de su calidad ya que ejercen una gran influencia sobre el color, la astringencia, el cuerpo, su capacidad para el envejecimiento y en general la textura del vino. De forma tradicional los taninos del vino proceden de forma natural de las bayas, liberándose de las semillas y las pieles durante la vinificación, o bien de la crianza o de la suplementación con taninos comerciales. En el capítulo 1 de la presente tesis se estudia la relación entre la morfología de la baya y el color, la composición en taninos y la astringencia de los vinos tintos de cuatro variedades: Merlot, Cabernet Sauvignon, Tempranillo y Garnacha. La principal conclusión de este trabajo fue que el procentaje en peso de las semillas respecto del peso de la baya es un factor determinante de la concentración en taninos y la astringencia del vino. En el capítulo 2 de la presente tesis se estudia el efecto como copigmentos de los taninos enológicos y se concluye que todos los taninos enológicos estudiados son muy eficaces como copigmentos. Asimismo se propone un índice para medir la eficacia de los diferentes taninos comerciales. En el capítulo 3 de la presente tesis se estudia la interacción entre 3 tipos de taninos y la mucina mediante resonancia de plasmones superficiales (SPR). Para ello se determinaron las constantes cinéticas y termodinámica de la interacción así como el índice de astringencia de los diferentes taninos. Las constantes de disociación termodinámica y cinética de las interacciones taninos-mucina presentaron los coeficientes de correlación más altos con el índice de astringencia. Estos datos sugieren que la percepción de astringencia no solamente depende de la estabilidad termodinámica del complejo-tanino proteína sino también probablemente del tiempo que tarda este complejo en disociarse.
Tannins are determinants of the quality of red wine since they exert a great influence on the color, astringency, body, capacity for aging and in general on texture of the wine. Traditionally, tannins come naturally from the berries, being released from seeds and skins during vinification, or from the aging or supplementation with commercial tannins. Chapter 1 of this thesis studies the relationship between berry morphology and color, tannin composition and astringency of red wines of four varieties: Merlot, Cabernet Sauvignon, Tempranillo and Garnacha. The main conclusion of this work was that the seed percentage weight respecto to berry weight weight is the main is a determining factor tannin concentration and the astringency of the wine. In Chapter 2 of this thesis studies the effect as co-pigments of oenological tannins and it is concluded that all oenological tannins studied are very effective as co-pigments. An index is also proposed to measure the effectiveness as copigments of the different commercial tannins. Chapter 3 of this thesis studies the interaction between 3 types of tannins and mucin by means of surface plasmon resonance (SPR). With this aim, the kinetic and thermodynamic constants of the interaction were determined as well as the astringency index of the different tannins. The thermodynamic and kinetic dissociation constants of the tannin-mucin interactions had the highest correlation coefficients with the astringency index. These data suggest that astringency depends not only on the thermodynamic tendency to form the complex between tannins and salivary proteins but also probably on the time required to dissociate the complex.

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Shumaker-Parry, Jennifer Sue. "Quantitative aspects of SPR spectroscopy and SPR microscopy, applications in protein binding to immobilized vesicles and dsDNA arrays /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/11600.

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Maignan, Jordany Richarlson. "Development of Orally Bioavailable 4(1H)-Quinolones and 1,2,3,4-Tetrahydroacridin-9(10H)-ones with Potent Anti-malarial Activity." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5873.

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Although Malaria rates are on the decline due to the efforts of the World Health Organization and other organizations dedicated to the eradication of this disease, a relaxed attitude towards the development of new antimalarial entities would be flawed. Due to the emergence of resistance in the parasite, the almost 50% world-wide reduction in malarial death rates that have been produced over the past 15 years are threatening to be lost New drugs are urgently needed and our approach focuses on the re-evaluation and optimization of the historic antimalarial ICI 56,780. Due to its causal prophylactic activity, along with its ability to prevent transmission and potent blood schizonticidal activities, it was revisited with the hopes of first understanding which functionalities were responsible to the compound's activity. Secondly, we wanted to optimize the substituents in the 3, 6 and 7-positions. Finally and most importantly, we wanted to address the cross-resistance problem of the ICI 56,780 scaffold. Initial, analogues showed the importance of the ester in facilitating the convergence of the RI towards 1. Although those analogues lost activity in W2, TM90-C2B, and Pb, they were our first glimpse at this important trend that was later exploited in our 3-halo-6-butyl-7-(2-phenoxyethoxy)quinolin-4(1H)-one and 3-halo-6-butyl-2-methyl-7-(2-phenoxyethoxy)quinolin-4(1H)-ones which showed RI values of < 5 for our best analogues. Although our lead compound 3-bromo-6-butyl-2-methyl7-(2phenoxyethoxy)quinolin-4(1H) one possessed decreased activities as compared to ICI 56,780 at 2.60 nM for W2, 12.2 nM for TM90-C2B and 2.12 nM for Pb, it had 100% inhibition of parasite development on day 6 PE in our scouting assay and 61% inhibition on day 6in our Thompson model, increased from the < 2% value given by the ICI 56,780. Solubility and unfavorable in vivo stability were still major issues for this scaffold. Therefore, a series of piperazinyl 4(1H)-quinolones with greatly enhanced solubility were designed and tested in detailed structure activity relationships and structure property relationship studies. Initial results showed that 7-piperazinyl-4(1H)-quinolones possessed greatly increased solubilities when compared to ICI 56,780 analogues. Primarily, the linker length and the piperazine core was probed. This showed that compounds with a single carbon spacer were most active. Further testing of the 6-position gave methyl 6-methyl-4-oxo-7-((4-phenylpiperazin-1-yl)methyl)-1,4-dihydroquinoline-3-carboxylate with W2 and TM90-C2B values of 0.435 nM and 147 nM respectively. Substitution on the piperazinyl phenyl gave the most active compounds however the RI of >1500 was unacceptable. Because of this, 3-halo substituents were added to these quinolones with promising results. With RIs of < 3, the compounds were promising, however they were not active in vivo. However, methyl 6-methoxy-4-oxo-7-((4-(4-(trifluoromethyl)phenyl)piperazin-1-yl)methyl)-1,4-dihydroquinoline-3-carboxylate and methyl 6-methyl-4-oxo-7-((4-(4-(trifluoromethyl)phenyl)piperazin-1-yl)methyl)-1,4-dihydroquinoline-3-carboxylate both gave cures in our in vivo Thomson model. These studies highlight the potential in using detailed structural activity and structural property studies to re-evaluate and optimize historic antimalarials. These studies have introduced a new generation of soluble 4(1H)-quinolones with high potency against P. falciparum.

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Saxton, Julie Elizabeth. "SPR with nanoparticles for gas phase detection." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614753.

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Pereira, Roberta Andressa. "Morfoanatomia de Androtrichum trigynum (Spr.) Pfeiffer (Cyparaceae)." reponame:Repositório Institucional da UFSC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/93125.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biologia Vegetal, Florianópolis, 2009.
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Androtrichum trigynum (Spr.) Pfeiffer é um gênero monotípico da família Cyperaceae ocorrendo em regiões litorâneas da costa sudoeste atlântica. Apresenta o sistema subterrâneo constituído por rizomas e raízes adventícias. Neste trabalho foram investigadas a ontogênese do sistema subterrâneo e análises quantitativas do rizoma, raízes e escapos florais de A. trigynum, coletados em dois ambientes da restinga do Parque Municipal das Dunas da Lagoa da Conceição em Florianópolis, caracterizados por dunas semifixas (DS) e baixadas úmidas (BU). Amostras do sistema subterrâneo e escapo foram coletados, fixados em FAA 70 e gluteraldeído 2,5% e processadas de acordo com as técnicas usuais em anatomia vegetal. O rizoma é espessado, plagiotrópico e simpodial, dele partem, escapos florais cuja base é coberta por catafilos, e as raízes. A partir do promeristema do rizoma diferencia-se a protoderme, o procâmbio e o meristema fundamental. Com o desenvolvimento, o meristema de espessamento primário (MEP) é observado entre a região cortical e o cilindro vascular. O MEP produz centrifugamente células parenquimáticas e centripetamente feixes vasculares anfivasais e células parenquimáticas. Posteriormente, a partir do MEP diferenciam-se a endoderme e o periciclo. Em secção longitudinal do ápice radicular são evidentes o caliptrogênio, que origina a coifa; o promeristema, o meristema fundamental, a protoderme e o procâmbio. Inicialmente a epiderme está constituída de células papilosas que secretam grande quantidade de substâncias entre estas e as células da coifa; a endoderme meristemática forma o córtex interno. Na maturidade parte do córtex interno desenvolve-se em aerênquima esquisolisígeno e as células corticais mais internas tornam-se espessadas. As células da endoderme são alongadas no sentido radial e apresentam paredes finas. O periciclo é plurisseriado. Muitos idioblastos contendo compostos fenólicos são encontrados no rizoma, raízes adventícias e escapos florais. Foram analisadas as seguintes características: diâmetro das raízes e rizoma; comprimento, diâmetro e área dos escapos florais; comprimento e diâmetro dos elementos de vaso das raízes, rizomas e escapos florais; grau de esclerofilia, densidade estomática, distância entre estômatos, comprimento total e parcial das células guarda e largura das células subsidiárias e espessura da cutícula e parede periclinal externa da epiderme do escapo floral, as médias foram comparadas por teste T de Student e estatística descritiva com o auxílio do programa Excel e BioEstat 5,0, porcentagens de similaridade e Análise de Similaridade foram usadas para contrastar a procedência e período de coleta e MDS foi empregado para mostrar a distribuição espacial das amostras. De maneira geral, os resultados indicam que a espécie apresentou maiores taxas de crescimento durante o verão, ou seja, no período mais úmido, mostrando-se adaptada ao ciclo hidrológico de alagamentos e drenagens das baixadas úmidas, ao resistir ao alagamento. Através do MDS, foi observada certa tendência à separação das características anatômicas em quatro grupos (BU inverno e verão e DS inverno e verão). A. trigynum apresentou características xeromorfas, embora elas ocorram em indivíduos de ambientes úmidos, provavelmente em conseqüência de pseudo xeromorfismo ou escleromorfismo oligotrófico, causado principalmente por falta de nutrientes no solo.

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Gamsjaeger, Roland. "AFM and SPR on biological systems applying atomic force microscopy (AFM) and surface plasmon resonance (SPR) to biologically important systems." Saarbrücken VDM Verlag Dr. Müller, 2007. http://d-nb.info/988909820/04.

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Bergström, Anna. "SPR Sensor Surfaces based on Self-Assembled Monolayers." Thesis, Linköping University, Department of Physics, Chemistry and Biology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-16664.

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The study and understanding of molecular interactions is fundamentally important in today's field of life sciences and there is a demand for well designed surfaces for biosensor applications. The biosensor has to be able to detect specific molecular interactions, while non-specific binding of other substances to the sensor surface should be kept to a minimum. The objective of this master´s thesis was to design sensor surfaces based on self-assembled monolayers (SAMs) and evaluate their structural characteristics as well as their performance in Biacore systems. By mixing different oligo (ethylene glycol) terminated thiol compounds in the SAMs, the density of functional groups for bimolecular attachment could be controlled. Structural characteristics of the SAMs were studied using Ellipsometry, Contact Angle Goniometry, IRAS and XPS. Surfaces showing promising results were examined further with Surface Plasmon Resonance in Biacore instruments.

Mixed SAM surfaces with a tailored degree of functional COOH groups could be prepared. The surfaces showed promising characteristics in terms of stability, immobilization capacity of biomolecules, non-specific binding and kinetic assay performance, while further work needs to be dedicated to the improvement of their storage stability. In conclusion, the SAM based sensor surfaces studied in this thesis are interesting candidates for Biacore applications.

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Kärnhall, Johan. "New SPR based assays for plasma protein titer determination." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-70044.

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Reliable analytical tools are important for time efficient and economical process development, production and batch release of pharmaceuticals. Therapeutics recovered from human plasma, called plasma protein products, involve a large pharmaceutical industry of plasma fractionation. In plasma fractionation of human immunoglobulin G (hIgG) and albumin (HSA) recommended analysis techniques are regulated by the European Pharmacopoeia and are including total protein concentration assays and zone electrophoresis for protein composition and purity. These techniques are robust, but more efficient techniques with higher resolution, specificity and less hands-on time are available. Surface plasmon resonance is an optical method to study biomolecular interactions label-free in real time. This technology was used in this master thesis to set up assays using Biacore systems for quantification of HSA and hIgG from all steps of chromatographic plasma fractionation as a tool for process development and in-process control. The analyses have simplified mass balance calculations to a high extent as they imply specific detection of the proteins compared with using total protein detection. The assays have a low hands-on time and are very simple to perform and the use of one master calibration curve during a full week decreases analysis time to a minimum. Quick, in-process control quantification of one sample is easily obtained within <10 minutes. For final QC of hIgG or for process development, an assay to quantify the distribution of the IgG subclasses (1-4) was set up on Biacore and showed significantly lower hands-on time compared with a commercial ELISA. All assays showed reliable quantification and identification performed in unattended runs with high precision, accuracy and sensitivity.

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Wijaya, Edy. "Design and optimization of Surface Plasmon Resonance (SPR) biosensors." Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10096/document.

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En terme de performance, le biocapteur idéal doit avoir très grande sensibilité, basse limite de détection et temps d’analyse qui est extrêmement court. Les biocapteurs sans marquage à base de résonance de plasmons de surface (biocapteurs SPR) possèdent naturellement le temps d’analyse le plus court parmi différent types de biocapteurs. Leur limite de détection n’est cependant pas la plus impressionnante. Il y a donc un besoin pour augmenter considérablement la sensibilité intrinsèque des biocapteurs SPR afin de permettre de plus basses limites de détection. Quelques approches pour exalter la sensibilité optique des biocapteurs SPR dans la configuration « traditionnel » de Krestchmann telles que film SPR bimétallique, plasmons à longues portées et détection dans l’infrarouge proche sont examinées dans ce travail. Des configurations « non traditionnelles » comme guides optiques planaires avec couplage par réseau et structures sub-longueur d’ondes ont été aussi théoriquement étudiées. Nouvelle stratégie de fonctionnalisation de surface à base de graphène qui augmente la sensibilité de reconnaissance biomoléculaire et peut être appliquée à quasiment toute structure SPR a été également démontrée
In terms of performance, the ideal biosensor should have high sensitivity, low limits of detection, and extremely short analysis time. Label-free surface plasmon resonance (SPR) biosensors naturally offer the shortest analysis time compared to other types of biosensors. On the other hand, the limits of detection of SPR biosensors are not the most impressive. The inherent sensitivity of SPR biosensors thus needs to be significantly improved to allow lower limits of detection. Several approaches for the enhancement of optical sensitivity of SPR biosensors in the “traditional” attenuated total reflection (ATR) Kretschmann configuration such as the use of bimetallic SPR film, long-range surface plasmons, and near-infrared operating wavelength have been investigated in this work. In addition, some “non traditional” configurations for SPR biosensors including grating-coupled planar optical waveguides and arrays of sub-wavelength structures have been theoretically studied. Novel graphene-based surface functionalization strategy with enhanced biorecognition sensitivity that can be applied to virtually any SPR structure has also been demonstrated

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Daniel, Camille. "Biopuce à aptamères anti-thrombine : exploration d'une technique alternative de détection." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00954086.

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Du fait de leur haute stabilité et bas coût de production, les aptamères suscitent un intérêt croissant, depuis près de 20 ans, dans le design de biocapteurs en tant qu'élément de reconnaissance idéal. Le but de ce travail de thèse est de démontrer l'intérêt et la pertinence d'un outil tel qu'une biopuce à aptamères, associant les avantages des sondes aptamères à ceux d'une détection par SPRi (Surface Plasmon Resonance imaging), permettant une détection sans marquage et en temps réel d'interactions moléculaires. Dans ce but, deux aptamères anti-thrombine (APT1 = 5′- GGT-TGG-TGT-GGT-TGG -3′ et APT2 = 5′-AGT-CCG-TGG-TAG-GGG-AGG-TTG-GGG-TGA-CT-3′) ont été choisis comme objets d'étude modèles. Ce choix a permis d'orienter différents axes de recherche : utilisés indépendamment comme sondes lors de l'élaboration de notre biopuce, ils ont tout d'abord permis de réaliser une détection cinétique optimisée de la thrombine, avec des performances remarquables pour une détection de ce type, ainsi que le calcul de constantes de dissociation en solution et à la surface des biopuces. Mais au-delà d'un simple biocapteur, la biopuce a également pu être utilisée comme véritable plateforme d'étude de la thrombine et de ses interactions, au sein de structures plus complexes telles que la structure " sandwich " entre les deux aptamères, ou d'autres interactions impliquant la thrombine en tant qu'acteur de la cascade de coagulation (inhibition de la thrombine par l'antithrombine III et le cofacteur II de l'héparine, transformation de la prothrombine au sein du complexe prothrombinase).

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Oliver, Jennifer Valerie. "Detection of phenols in water using SPR and specific receptors." Thesis, University of Kent, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252587.

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Lisi, Samuele. "Approches innovantes basées sur la Résonance des Plasmons de Surface pour le diagnostic biomoléculaire de la maladie d’Alzheimer." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAV003/document.

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La maladie d’Alzheimer est une pathologie neurodégénérative qui amène à une perte progressive de la mémoire et cause des changements comportementaux. Selon plusieurs théories, le développement de cette maladie est associé à l’accumulation du peptide amyloïde beta et de la protéine tau dans des zones précises du cerveau humain. A l’heure actuelle, les approches thérapeutiques testées sont fondées sur l’hypothèse de la cascade amyloïde, mais les résultats n’ont pas été jugés suffisamment efficaces. Pour augmenter les chances de succès des traitements thérapeutiques existants, de meilleures techniques pour un dépistage précoce de l’Alzheimer semblent nécessaires. De ce fait, dans cette thèse, des stratégies innovantes pour l’analyse d’un des biomarqueurs de la maladie d’Alzheimer sont proposées. En particulier le projet porte sur l’analyse de la protéine tau avec des biocapteurs basés sur la Résonance de Plasmons de Surface (SPR). L’augmentation du niveau de ce biomarqueur dans le Liquide Céphalo-Rachidien (LCR) est déjà indicateur d’un processus de neurodégénérescence. De plus, si la mesure de la protéine tau est combinée à celle d’autres biomarqueurs de la pathologie (i.e. : amyloïde beta), les possibilités de dépistage sont fortement augmentées. Les travaux ont portés sur deux aspects : initialement l’interaction antigène-anticorps a été exploitée pour développer un immunocapteur pour la protéine tau. En utilisant cette technologie, nous avons pu caractériser les paramètres analytiques de l’essai direct (avec un seul anticorps) et ceux de l’essai sandwich (avec deux anticorps complémentaires). Dès ces premières approches, nous avons remarqué le besoin d’augmenter la sensibilité de la méthode SPR développée. En effet la limite de détection pour l’essai sandwich était de l’ordre du nM, alors que les niveaux de tau dans le LCR sont de l’ordre du pM. L’utilisation de nanotechnologies, en particulier des nanotubes de carbone, a permis d’atteindre des niveaux proches du pM, avec de bonnes performances en terme de répétabilité de l’essai.Une approche alternative a été conçue dans la deuxième partie du projet. Elle était consacrée à la sélection d’un aptamère pour la protéine tau, afin d’exploiter les avantages de cette classe de récepteurs par rapport aux anticorps. Pour accomplir cet objectif, deux stratégies de sélection ont été mises en place. Premièrement la sélection traditionnelle (SELEX, Systematic Evolution of Ligands by EXponential enrichment) a été appliquée en utilisant l’Electrophorèse Capillaire (EC) comme moyen de séparation. Bien que de nombreuses conditions aient été modifiées, avec le SELEX traditionnel nous n’avons pas observé une évolution significative de l’affinité entre les séquences d’ADN et la protéine tau. Dans la deuxième approche nous avons utilisé la même méthode de séparation pour mener la sélection à travers l’EC-Non-SELEX. En utilisant cette méthode, où les étapes de PCR étaient réduites, une évolution positive a été observée après seulement trois rounds. En effet cinq séquences parmi celles issues du dernier round ont montré une affinité supérieure pour la cible par rapport à la banque. Néanmoins le nombre de séquences analysées à la fois par SPR et par anisotropie de fluorescence reste extrêmement limité par rapport au pool initial. Même si ceci semble être une limite, ce travail est le premier où les aptamères sont appliqués à l’analyse de la protéine tau. Le potentiel de cette classe de récepteurs reste en grande partie inexploré, ce qui laisse entrevoir des améliorations possibles de l’affinité grâce à de meilleurs processus de sélection et au développement de nouveaux outils bioinformatiques.En conclusion la SPR grâce à ses caractéristiques jouera un rôle fondamental dans les prochaines années pour l’analyse des biomarqueurs et pour le screening de nouvelles molécules, qui seront l’objet de futurs essais cliniques pour limiter l’agrégation de la protéine tau
Alzheimer’s disease (AD) is a widespread pathogenic condition causing memory and behavior impairment mostly in elderlies because of the accumulation of amyloid beta peptide and tau protein in human brain. Current therapeutic approaches, based on the amyloid hypothesis, are unable to arrest the progression of the disease, hence early diagnosis is crucial for an effective intervention. Based on the updated criteria for AD probable diagnosis, and considering the limits associated with the actual analytical techniques, my work in this thesis was dedicated to develop novel strategies for AD diagnosis. The whole project focused on the analysis of tau protein by Surface Plasmon Resonance (SPR) biosensing. Such protein is well known for being relevant as neurodegenerative marker. In particular if the measurement of tau is associated with that of the amyloid beta peptide and that of the phosphorylated tau, the clinical specificity of this protein become significant to detect Alzheimer. Two aspects were studied; first of all an immunosensor was developed taking advantage of the well-established antigen-antibody interaction. After characterization of the analytical parameters of the direct assay (with primary antibody), a sandwich assay (using two monoclonal antibodies mapping on different analyte i.e. protein tau epitopes) was developed, allowing very low sensitivity to be obtained in artificial Cerebrospinal Fluid (aCSF). In particular to enhance the analytical signal Carbon Nano Tubes (CNTs) were used. Secondly, the research was focused on the selection of aptamers for tau. To this aim two SELEX (Systematic Evolution of Ligands by EXponential enrichment) methods were compared, both based on Capillary Electrophoresis (CE) for partitioning step of the process. Whether with CE-SELEX (first method), no significant affinity improvement was measured, using the CE-Non-SELEX (second method) affinity of the DNA library for tau protein was consistently improved. After isolation of a limited population of aptamer candidates, five sequences were chosen to be analyzed for their affinity for the target. Fluorescence Anisotropy (FA) measurements and SPR highlight similar behavior for the selected sequences, despite the detection principles of these techniques are significantly different. In conclusion the work highlight versatility of SPR technology used both for quantitative analysis and for new selected aptamers characterization in terms of affinity for the analyte tau. The above mentioned versatility is of great interest in a field such AD, which is rapidly expanding. Lowering the total tau levels has been recently identified as a new goal for therapy. Therefore many drug candidates are likely going to be tested in the near future. SPR technology is already widely used in pharmaceutical industry to investigate novel molecules, since it gives access to a large panel of information. In this panorama aptamer technology may improve the overall quality of the analytical data, allowing better comparison among drug candidates. With respect of these receptors, the thesis opened the door to new studies for DNA aptamers to recognize tau, with considerable advantages in term of the receptor stability. Moreover the whole potential of DNA aptamers selected in this work still remain to be explored. New selection methodologies, combined with fast progression of bioinformatics tools might give rise to affinity improvement, which will lead to sensitivity improvement for tau detection in the next few years

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Adducci, Benjamin Augustus. "Detection of a Surrogate Biological Threat Agent (Bacillus globigii) with a Portable Surface Plasmon Resonance Biosensor." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/73535.

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New methods and technology are needed to detect biological agents that threaten the health of humans and domestic animals. The bacterium Bacillus anthracis, causal agent of anthrax, has been used as a biological warfare agent. Here, we extend the work of Chinowksy et al. (2007) to the detection of a surrogate of B. anthracis, B. globigii (also known as B. atrophaeus, B. subtilis var. niger, B. subtilis var. subtilis) in a mixed sample containing two different species of Bacillus using a portable surface plasmon resonance (SPR) biosensor (SPIRIT 4.0, Seattle Sensor Systems). Two methods (direct capture and antibody injection) were used to determine the limit of detection for spores of B. globigii and to detect spores of B. globigii in a mixed sample containing at least one other Bacillus spp. Spores of B. globigii were detected on freshly coated sensors (not previously exposed to spores) with direct capture at a minimum concentration of 10^7 spores/mL, and with antibody injection at a concentration of 10^5 spores/mL. Spores of B. globigii were also detected when mixed with B. pumilus spores in the same sample at equal concentrations (107 spores/mL) using antibody injection. An SPR method using synthetic miRNA was adapted to the portable SPR unit (SPIRIT), and preliminary experiments suggested that the target sequence could be detected. SPR methods using nucleic acids have an exciting future in the detection of biological agents, such as B. anthracis. With the availability of portable instrumentation to accurately detect biological warfare agents such as B. anthracis, emergency responders can implement emergency protocols in a timely fashion, limiting the amount of people and domestic animals exposed.
Master of Science

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14

Adamson, Roslin Jane. "Probing GPCR-Gα interactions : a functional study by EM and SPR." Thesis, University of Oxford, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.669745.

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15

Bang, Hyungseok. "INTEGRATED OPTICAL SPR (SURFACE PLASMON RESONANCE) SENSOR BASED ON OPTOELECTRONIC PLATFORM." Doctoral diss., University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3289.

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Current major demands in SPR sensor development are system miniaturization and throughput improvement. Structuring an array of integrated optical SPR sensor heads on a semiconductor based optoelectronic platform could be a promising solution for those issues, since integrated optical waveguides have highly miniaturized dimension and the optoelectronic platform enables on-chip optical-to-electrical signal conversion. Utilizing a semiconductor based platform to achieve optoelectronic functionality poses requirements to the senor head; the sensor head needs to have reasonably small size while it should have reasonable sensitivity and fabrication tolerance. This research proposes a novel type of SPR sensor head and demonstrates a fabricated device with an array of integrated optical SPR sensor heads endowed with optoelectronic functionality. The novel integrated optical SPR sensor head relies on mode conversion efficiency for its operational principle. The beauty of this type of sensor head is it can produce clear contrast in SPR spectrum with a highly miniaturized and simple structure, in contrast to several-millimeter-scale conventional absorption type or interferometer type sensor heads. The integrated optical SPR sensor with optoelectronic functionality has been realized by structuring a dielectric waveguide based SPR sensor head on a photodetector-integrated semiconductor substrate. A large number of unit sensors have been fabricated on a substrate with a batch fabrication process, which promises a high throughput SPR sensor system or low-priced disposable sensors.
Ph.D.
Optics and Photonics
Optics and Photonics
Optics PhD

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16

Krause, Simone Janine [Verfasser]. "SPR-Analytik von Tetracyclinen in Matrices tierischer Herkunft / Simone Janine Krause." Wuppertal : Universitätsbibliothek Wuppertal, 2013. http://d-nb.info/1045118141/34.

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17

Arechabaleta, Rafael. "AFM and SPR studies of protein adsorption at solid/liquid interface." FIU Digital Commons, 1999. http://digitalcommons.fiu.edu/etd/1054.

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Membrane-like structure formed by surfactant molecules of didodecyldimethylammonium bromide (DDAB) on both HOPG and gold electrodes were studied with AFM and SPR techniques. The study shows that the thickness of the adsorbed layer of DDAB is strongly dependent on the concentration of the vesicle solution. We have also investigated the adsorption of redox protein, Cytochrome c, on graphite electrode with in situ tapping mode AFM. The protein adsorbs spontaneously onto the electrode covered with an adsorbed phosphate layer and forms a uniform monolayer. The adsorbed protein exhibits a reversible electron transfer at 0.17 V (Ag/AgCI) once the electrode potential has been increased to 0.75V. Using surface plasmon resonance spectroscopy we have measured subtle conformational change in protein, Cyt c, due to electron transfer of a single electron on MPA-coated gold electrode. The electron transfer induced change in the resonant angle is about 0.006 deg., which corresponds to ~ 0.2 A decreases in the thickness. This is consistent with that reduced state is more compact than the oxidized state.

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18

Carregaro, Fernanda. "Estudo das proteínas pequenas ricas em prolina (SPRRs) em câncer de cabeça e pescoço." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/41/41131/tde-18012013-153012/.

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As proteínas pequenas ricas em prolina (small proline-rich protein/SPRRs) compreendem uma sub-classe específica de precursores da camada córnea, codificadas por uma família multi-gênica do complexo de diferenciação epidérmica mapeado no cromossomo 1q21. Vários estudos têm sugerido que as SPRs estão relacionadas com proliferação epitelial elevada e processos malignos. O presente trabalho teve como objetivo investigar a participação das SPRs no desenvolvimento de carcinomas epidermóides de cabeça e do pescoço e no fenótipo da célula neoplásica. O perfil de expressão de onze genes SPRRs foi avaliado em cinco linhagens celulares (FADU, HEP-2, UM-SCC-38, SCC-9) e em carcinomas primários da cabeça e pescoço, utilizando PCR em tempo real. Os tumores foram classificados em agressivos (A) e menos agressivos (LA) dependendo da presença ou da ausência de células neoplásicas nos nódulos linfáticos regionais. Os resultados revelaram baixa expressão de genes SPRRs em todas as linhagens celulares, exceto o SPRR4. Por outro lado, foram observados níveis elevados de transcritos de SPRR2G, SPRR4 e SPRR2E e níveis reduzidos de transcritos de SPRR3 tanto nos grupos A e LA de carcinomas. A expressão ectópica de SPRR2E resultou em menor capacidade de invasão celular em ensaio de câmara de Boyden, bem como em mudança do fenótipo epitelial para fibroblastóide, mas não afetou a proliferação celular ou a migração. Após o tratamento das células HEP-2 com a proteína anti-inflamatória anexina A1 (peptídeo AC2-26), ocorreu um aumento substancial de expressão da maioria dos SPRRs, sugerindo uma associação entre SPRs e inflamação. Os genes SPRRs possuem sequências altamente conservadas e, após uma análise filogenética utilizando o método de neighbor-joining, os resultados indicaram um grupo homogêneo, que incluiu SPRR2 e SPRR4, e um grupo mais heterogêneo com SPRR1 e SPRR3. Aparentemente, a diversidade de sequência destes genes é baixa. Isto sugere que o controle da dosagem da proteína pode ser mais importante para o desempenho de sua função que a complexidade estrutural. A compreensão da função das SPRs avançou bastante nos últimos anos, mas muitas questões sobre o seu papel no processo neoplásico ainda permanecem sem resposta. Muitos dados são ainda necessários para identificar sua associação com outras proteínas e com vias de sinalização. Portanto, é importante melhorar nosso conhecimento sobre a regulação e a função de cada RPN, para que as descobertas obtidas na pesquisa básica sejam traduzidas em aplicações clínicas
The small proline rich proteins (SPRs) constitute a specific sub-class of cornified cell envelope precursors, encoded by a multi-gene family which are part of the epidermal differentiation complex on chromosome 1q21. Several studies have suggested that the SPRs are related to increased epithelial proliferation and to malignant processes. The present work aimed to investigate the participation of SPRs in the development of head and neck squamous cell carcinomas and in the phenotype of the neoplastic cell. The expression profile of eleven SPRRs genes was evaluated in five cell lines (FaDu, HEP-2, UM-SCC-38, SCC-9) and in primary carcinomas from head and neck, using real time PCR. The tumors were classified as aggressive (A) and less aggressive (LA) depending on the presence or absence of neoplastic cells in the regional lymph nodes. The results revealed low expression of SPRRs genes in all cell lines, except SPRR4. Otherwise, high levels of SPRR2G, SPRR4 and SPRR2E and low levels of SPRR3 transcripts were observed in both A and LA carcinomas. Ectopic SPRR2E expression resulted in reduced cell invasion evaluated by a Boyden chamber assay together with morphologic changes from epithelial to fibroblast-like phenotype, but did not affected cell proliferation or migration. After treatment of HEP-2 cell line with the anti-inflammatory protein annexin A1 (peptide Ac2-26), there was a substantial increase of expression of most SPRRs, suggesting an association between SPRs and inflammation. The SPRRs genes have highly conserved sequences and, after a phylogenetic analysis using the neighbor-joining method, the results indicated a homogeneous group including SPRR2 and SPRR4, and a more heterogeneous group with SPRR1 and SPRR3. Apparently, the sequence diversity of these genes is low. This suggests that the control of protein dosage may be more important to the performance of their function than the structural complexity. The understanding of the function of SPRs has advanced in the past years but many questions on their role in the tumorigenic process still remain unanswered. Much more data are required to recognize their association to other proteins and signaling pathways. Therefore, it is important to improve our knowledge on the regulation and function of each SPRs in order to translate findings from basic research into clinical applications

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19

Jiménez-Castells, Carmen 1982. "Capture and identification of carbohydrate-binding proteins by SPR and CREDEX-MS." Doctoral thesis, Universitat Pompeu Fabra, 2010. http://hdl.handle.net/10803/7237.

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Carbohydrate-binding proteins of non-immunological origin -lectins- have been recognized over the last decades as decisive players in numerous biological processes, ranging from cellcell communication, fertilization, pathogen-cell adhesion to metastasis. Consequently, there is an increasing interest in finding powerful and nanosized tools to screen for these molecules and to study their carbohydrate interactions in detail. Here, two complementary approaches are described to characterize lectin-carbohydrate interactions with high sensitivity, low sample consumption, and without the need for sample labelling: SPR and CREDEX-MS. In SPR, we have developed an approach where the sugar is immobilized onto a sensor surface through a tailor-made peptide module that allows (1) to capture the lectin, (2) to characterize the interaction through kinetic and thermodynamic parameters, and (3) to identify the interacted protein by mass spectrometry. In CREDEX-MS, based on proteolytic excision of proteincarbohydrate complexes and mass spectrometric analysis, the peptides comforming the carbohydrate binding domain are identified.
Las lectinas (proteínas de origen no inmune capaces de reconocer azúcares) se han revelado en las últimas décadas como participantes cruciales en multitud de procesos biológicos, tales como la comunicación célula-célula, la fertilización, la adhesión del patógeno a la célula y la metástasis, entre muchos otros. Por lo tanto, existe un gran interés en el desarrollo de técnicas analíticas potentes para el estudio de las interacciones lectina-carbohidrato. En este trabajo, se describen dos aproximaciones complementarias mediante las cuales se pueden caracterizar las interacciones lectinas-azúcar con gran sensibilidad, poca utilización de muestra y sin la necesitad de ningún marcaje. En la técnica basada en resonancia de plasmón superficial (SPR), el azúcar es inmovilizado sobre una superficie a través de un módulo peptídico, lo cual permite (1) capturar la lectina, (2) caracterizar su interacción mediante parámetros cinéticos y termodinámicos y (3) identificar posteriormente la proteína mediante espectrometría de masas. Complementariamente, la técnica CREDEX-MS, basada en la excisión proteolítica del complejo proteína-azúcar y posterior análisis por espectrometría de masas, nos permite identificar los péptidos que forman parte del dominio de unión al azúcar.

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20

Ekström, Emma. "SPR-based method for concentration determination of proteins in a complex environment." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-181524.

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In this project a method based on surface plasmon resonance has been developed for determining the concentration of several His-tagged proteins in complex solutions. It showed large dynamic range, no measureable non-specific binding and high sensitivity (with linear range around 0.1–10 μg/ml depending on the proteins). The method showed a low variation when checked on MBP-His during an extended time period. The concentrations of the His-tagged protein in the lysate has also been determined and compared with other alternative methods. This method will later be used to analyse protein concentrations during development and optimization of chromatographic purification process.

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21

Carandente, Mario. "FE simulation of the SPR process to predict joint characteristics : innovation report." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/94058/.

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Self-pierce riveting (SPR) is the core joining technology used by Jaguar Land Rover (JLR) to join aluminium & mixed material body in white (BIW). Currently, the application of this process has a serious constraint to the business due to the high investment and intensive labour required by physically testing joint feasibility. This is a critical issue especially where different stacks need to be joined by one SPR gun. In this case, the selection of a common rivet/die combination which suits different material stacks requires labour intensive work that in some cases can create long delays during a vehicle development and commissioning. In this context, the development of a simulation technique, based on Finite Element Analysis (FEA), could allow virtual assessment of the manufacturing feasibility of a joint. This will enable significant business benefits including: saving time, costs and materials requirement for the experimental trials. Three major challenges need to be addressed: short CPU time, accuracy and robustness in order for its application in a manufacturing environment. To achieve these objectives, detailed numerical methods capable of reproducing the key factors affecting the experimental process like tooling, boundary conditions and material plastic deformation are developed. For the first time, a thermo-mechanical finite element model for simulation of the SPR process has been proposed. This allowed consideration of the increase in temperature due to friction and plastic deformation generated during the rivet insertion. The effect of thermal softening and strain hardening were characterized for the development of the substrate material model and their influence on the numerical simulation was assessed. This study has been validated via production line data and a significantly high level of correlation between simulation and experimental data for over 1000 joints representative of a vehicle platform has been achieved. The application of the developed simulation technique will enable several business benefits such as significant reduction of engineering time and costs in contrast to the experimental procedure. These advantages allow a smooth implementation of the SPR process in a JLR production line by providing engineering recommendations rapidly and consistently. All these features, combined with accuracy and robustness have enabled the application of the developed tool into JLR business.

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22

Cao, Yihong. "Sugar and Peptide mimics for SPR Characterization of autoantibodies in monoclonal gammopathy." Phd thesis, Université de Cergy Pontoise, 2013. http://tel.archives-ouvertes.fr/tel-00877262.

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IgM monoclonal gammopathy is a common age-related demyelinating sensory and motor polyneuropathy. It has been shown to be associated with antibodies against myelin-associated glycoproteins (MAG/SGPG). The HNK-1 carbohydrate epitope is a terminal 3-sulfo-glucuronyl residue attached to lactosamine structures and it is shared both in MAG and SGPG (SO4-3-GlcA(β1-3)Gal-(β1-4)GlcNAc(β1-3)Gal-(β1-4)Glcβ(1-1′)Cer). It is mostly expressed in the nervous system and plays an important role in preferential motor reinnervation. Nevertheless, the HNK-1 epitope is difficult to be isolated and synthesized and diagnostic assays used in the clinics are not always reproducible and reliable. Therefore in our study, our goal is to identify a simple synthetic diagnostic tool (peptide or monosaccharide), mimetic of the HNK-1 epitope, able to recognize antibodies in neurogammopathies sera by Surface Plasmon Resonance to be used in earlier stage patients and possibly to monitor disease activity. For this reason, we firstly tried to synthesize this trisaccharide and then we achieved the synthesis of its terminal monosaccharides with different function groups (octyl glucopyranoside, octyl glucuronic acid, octyl 3-O-sulfo-glucuronic acid and 8-amino octyl 3-O-sulfo-glucuronic acid). Then 10 linear and cyclic peptides conformationally and/or structurally mimicking HNK-1 were also synthesized (LSETTI, LSETTl, cyclo(-TTILSE-), cyclo(-TTlLSE-), cyclo(-TKTlLSE-), cyclo(-TETKlLSE-), TYTKlLSE, TY(SO3)TKlLSE, cyclo(-TYTKlLSE-) and cyclo(-TY(SO3)TKlLSE-)). The SPR kinetic binding affinities of all these sugar and peptide mimics were studied with commercial anti HNK-1 antibody using Biacore. Moreover, mimics with highest binding affinities were chosen for antigen-antibody interaction study in IgM gammopathy patients' serum.

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23

Salazar, A. "Conception d'un Imageur CMOS à Colonne Active pour un Biocapteur Optique SPR." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00932309.

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Cette thèse présente la conception et le développement d'un imageur CMOS pour bio-capteurs optiques basé sur la résonance plasmonique de surface ou SPR (de l'anglais Surface Plasmon Resonance). Premièrement, les conditions optimales pour la résonance de plasmon dans une interface compatible avec un processus CMOS/Post-CMOS sont obtenus par modélisation avec le logiciel COMSOL. Deuxièmement, un imageur CMOS à Colonne Active de 32x32 pixels est réalisé en technologie CMOS 0,35 m. Dans une interface or-eau avec excitation du prisme et une longueur d'onde de 633 nm, on constate que pour des prismes avec des indices de réfraction de 1,55 et 1,46, le couplage SPR optimal se produit à des angles d'incidence de 68,45◦ et 79,05◦ avec les épaisseurs des couches d'or de 50 nm et 45 nm respectivement. Dans ces conditions, environ 99,19% et 99,99% de l' ́energie de la lumière incidente sera transférée au plasmon de surface. Nous montrons aussi qu'un changement de 10−4 RIU dans l'indice de réfraction du milieu diélectrique, produit un changement de 0,01◦ dans l'angle de résonance de plasmonique, pour un schéma de modulation d'intensité lumineuse ce changement correspond à une variation de 0,08% dans l'énergie de la lumière réfléchie vue par le photodétecteur. Pour l'imageur CMOS conu, une photodiode caisson-N/subtrat-P est choisie en raison de sa faible capacit ́e de jonction, qui se traduit par un rendement quantique élevé et un gain de conversion élevé. Les simulations sur ordinateur avec Cadence et Silvaco donnent une capacité de jonction de 31 fF et un rendement quantique maximum de 82%. Le pixel de l'imageur est basé sur une configuration à trois transistors (3T) et a un facteur de remplissage de 61%. Le circuit de lecture utilise une technique de Colonne Active (ACS) pour réduire le bruit spatial (FPN) associés aux capteurs à pixels actifs traditionnels (APS). En outre pour compléter la réduction du bruit, un Double Echantillonnage Non-Corrélé (NCDS) et un Double Echantillonnage Delta (DDS) sont utilisés. Un montage optique expérimental est utilisé pour caractériser les performances de l'imageur, les résultats obtenus sont un gain de conversion de 7.3 V/e-, une photodiode avec une capacité de jonction de 21.9 fF, un bruit de lecture de 324,5 μV, ́equivalant approximativement à 45 lectrons, et une gamme dynamique de 62,2 dB. Les avantages de l'ACS et NCDS-DDS sont observés dans les bas niveaux de FPN de pixel et colonne de 0,09% et 0,06% respectivement. Le travail présenté dans cette thèse est une première étape vers le but de d ́evelopper une plateforme de biocapteur entièrement intégrée basée sur SPR, incorporant la source de lumière, l'interface SPR, le canal microfluidique, les éléments optiques et l'imageur CMOS.

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24

Subramanian, Kannan. "Kinetics of insulin - insulin receptor interaction using a surface plasmon resonance (SPR)." Thesis, University of Canterbury. Chemical and Process Engineering, 2014. http://hdl.handle.net/10092/9327.

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Type 2 diabetes or adult onset diabetes, has been a global epidemic for the past two decades, and the number of new cases accelerates every year. Insulin resistance is one of the major factors behind this, wherein the insulin receptor, which signals to regulate glucose levels, based on the hormone insulin, loses its sensitivity. Obesity is one other major concern which is caused due to the improper balance between the caloric intake and the energy utilized. Gastric bypass surgeries (GBP) are performed to avert obesity. However, a beneficial side-effect is that the state of insulin resistance is reset to near baseline levels within a few days after the procedure. The reason behind this remains unexplained, with possible humoral effects, hypothesized to occur after the bariatric procedure. In this work, high-five insect cell line was utilized to recombinantly produce full length insulin receptors (IR). However commercially sourced IR ectodomains (eIR – soluble version of the full length IR with the completely extracellular α subunits along with extracellular and transmembrane regions of the β subunit), were used to study the interaction. Measuring the kinetics of IR-insulin interactions is critical to improving our understanding of this disease. In this study, a multiplex surface plasmon resonance (SPR) assay was developed for studying the interaction between insulin and the eIR. A scaffold approach was used in which anti-insulin receptor monoclonal antibody 83–7 (Abcam, Cambridge, UK) was first immobilized on the SPR sensorchip by amine coupling, followed by eIR capture. The multiplex SPR system (ProteOn XPR36TM, Bio-Rad Laboratories, Hercules, CA) enabled measurement of replicate interactions with a single, parallel set of analyte injections, whereas repeated regeneration of the scaffold between measurements caused variable loss of antibody activity. The main approach was to replicate the physiological IR-insulin interaction using this assay. It was also observed that insulin at higher concentrations tend to form dimers and hexamers in solution. This was tested using size exclusion chromatography analysis and proved to be true. Therefore an alternative analyte with the similar binding properties and affinity of insulin and at the same time with reduced self- association characteristics was explored. Lispro, the analogue of insulin with reduced self-association properties (generated by swapping of residue 28 and 29 with Lys and Pro respectively) was finally used to study the interaction with eIR. Interactions between recombinant human insulin with eIR-A (A isoform of the insulin receptor ectodomain) followed a two-site binding pattern (consistent with the literature), with a high-affinity site (dissociation constant KD1 = 38.1 ± 0.9 nM) and a low-affinity site (KD2 = 166.3 ± 7.3 nM). The predominantly monomeric insulin analogue Lispro had corresponding dissociation constants KD1 =73.2 ± 1.8 nM and KD2 =148.9 ± 6.1 nM, but the fit to kinetic data was improved when conformational change factor was included in which the high-affinity site was converted to the low-affinity site. Kinetics of interaction of insulin with eIR-A and eIR-B isoforms were then compared. eIR-A bound insulin with apparently higher affinity (with both the binding sites) when compared with eIR-B. This was again consistent with literature that IR-A had two-fold higher affinity for binding insulin than IR-B. The assay was further extended to study the effect of external factors such as glucose, visfatin on this interaction. Glucose (the main biomolecule which is regulated by the IR-insulin interaction) was tested, if it had any direct effect on the interaction. It was observed that glucose did not have any effect on eIR-insulin interactions. Visfatin, an adipocytokine which has been highly debated in literature for its insulin mimetic effects and IR binding properties, was then tested. The standard assay did not provide much insights as the reference channel immobilized with 83-7 monoclonal antibody to the receptor had much affinity for visfatin, leading to non-specific binding and negative responses. Therefore, in an alternative methodology was used - visfatin, Lispro and insulin were immobilized on separate channels along with bovine serum albumin immobilized on reference channel and eIR isoforms used as analyte to study the effect of visfatin on IR. This study showed that visfatin, a higher molecular weight protein compared to insulin, bound both the eIR isoforms. This is consistent with literature that visfatin binds IR at a site distinct from insulin, but the assay described here could not confirm the fact that it mimicked the signalling carried out by IR-insulin binding. Further studies are required to interpret the kinetics of visfatin-eIR interaction. To my knowledge, this is the first SPR assay developed to study eIR-insulin interactions in real-time. This could potentially be extended to study the interaction of insulin with full length insulin receptors and the effect of humoral and other external factors on the interaction, without the need for insulin labelling.

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Banville, Frédéric Alexandre. "Amélioration de la résolution latérale en microscopie SPR/MCWG par reconstruction d'images." Mémoire, Université de Sherbrooke, 2014. http://hdl.handle.net/11143/6743.

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Les recherches pharmacologiques nécessitent des outils d'analyse capables de caractériser et d'étudier des structures ou phénomènes biologiques. Une plate-forme de microscopie exploitant la résonance de plasmons de surface permet de faire l'acquisition d'images étudiant des phénomènes au niveau de cellules individuelles. Les images acquises par ce type de plate-forme présentent la variation d'indice de réfraction du milieu observé en couplant une lumière incidente aux plasmons de surface à l'interface d'un métal et d'un diélectrique. La faible résolution latérale de ces images ne permet cependant pas d'en distinguer tous les détails. Cette limite de résolution est associée aux propriétés de l'onde de surface qui entraînent une dégradation de l'image par l'étalement directionnel de l'information sur plusieurs pixels. De nombreux groupes de recherche ont travaillé sur ce problème de résolution en explorant des alternatives matérielles, que ce soit au niveau du montage d'acquisition ou des échantillons. Cependant, ceux-ci ont dû faire certains compromis afin d'améliorer la résolution latérale occasionnant une limitation en résolution temporelle ou en indice de réfraction. L'approche préférée dans ce projet de maîtrise est l'utilisation de techniques de post-traitement des images (déconvolution, algorithme de reconstruction d'images) acquises par le système de microscopie. Cette approche permet de conserver un bon contraste dans les images acquises et une bonne résolution temporelle. Ce projet vise à améliorer la résolution latérale en microscopie de résonance de plasmons de surface (SPR) en utilisant un algorithme de reconstruction d'images. Une méthode comme celle-ci n'a jamais été exploitée pour résoudre ce problème de limitation en résolution. Dans ce projet, une image de meilleure résolution est obtenue en combinant l'information pertinente de plusieurs images où la direction d'excitation des plasmons de surface diffère. Ces images sont acquises à partir d'échantillons de guides d'ondes à gaine métallique (MCWG) dont les matériaux et structures sont connus. Ceux-ci sont composés de quatre couches et ont tout d'abord été fabriqués. Ces échantillons ont permis l'acquisition d'images de structures dont les dimensions et les paramètres sont connus. Un algorithme de restauration d'images a été développé et implémenté pour retirer la dégradation linéaire observée dans les images de microscopie SPR acquises. Celui-ci détermine l'information nécessaire à l'exécution de l'algorithme à partir des images acquises, et améliore la résolution en microscopie SPR par une opération logicielle ne faisant pas de compromis au niveau matériel. L'algorithme a été validé auprès des échantillons MCWG dont la couche diélectrique est composée de structures synthétiques ou de cellules biologiques. Une amélioration de 6 à 1 micromètres sur structures synthétiques a été démontrée, tandis que le traitement permet de distinguer des détails des images cellulaires qui n'étaient pas identifiables avant. Ainsi, grâce à cette amélioration de la résolution, l'application de cet algorithme facilitera l'étude et le développement de nouveaux médicaments pharmacologiques.

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26

Salazar, Soto Arnoldo. "Conception d'un imageur CMOS à colonne active pour un biocapteur optique SPR." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENT063/document.

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Cette thèse présente la conception et la mise en œuvre d'un imageur CMOS pour être utilisé dans biocapteurs intégrés basés sur Résonance Plasmonique de Surface (SPR). Tout d'abord, les conditions optimales pour la résonance plasmon dans une interface compatible CMOS / post-CMOS sont obtenus par modélisation avec COMSOL. Deuxièmement, un imageur CMOS de Colonne Actif (CMOS-ACS) du 32x32 pixels est mis en œuvre sur une technologie CMOS 0,35 um. Dans une interface d'or-eau avec une excitation de prisme, on constate que pour les prismes avec des indices de réfraction de 1,55 et 1,46, le couplage optimal avec le plasmon est obtenu pour des films d'or d'une épaisseur de 50 et 45 nm, respectivement. Dans ces conditions, environ 99,19% et 99,99% de l'énergie de la lumière incidente est transférée à le surface plasmon pour les deux prismes respectivement, à condition que la lumière incidente, avec une longueur d'onde de 633 nm, arrive avec un angle d'incidence de 68,45° et 79,05° respectivement. Il est également obtenu qu'un changement de RIU 10-4 de l'indice de réfraction du milieu diélectrique, produit un changement de 0,01 ° dans l'angle de résonance de plasmons qui, dans un schéma de modulation d'intensité de lumière produit une variation de 0,08% dans la lumière réfléchie au photodétecteur. En ce qui concerne le imageur CMOS, une photodiode n-well/p-substrate est choisi comme l'élément de photodétection, en raison de sa faible capacité de jonction, ce qui conduit à un rendement élevé et le gain de conversion élevé comparativement à une photodiode n-diff/p-substrate. Des simulations sur ordinateur avec Cadence et Silvaco produit une capacité de jonction de 31 FF et 135 fF respectivement. Le pixel de l'imageur est basé sur une configuration à trois transistors (3T) et présente un facteur de remplissage de 61%. Le circuit de lecture utilise une technique de capteur de colonne actif (ACS) pour réduire le bruit à motif fixe (Fixed Pattern Noise ou FPN en anglais) liée au le Capteur à Pixels Actif (APS) traditionnelle. En outre, Non-Corrélés Echantillonnage Double (Non-Correlated Double Sampling ou NCDS en anglais) et Delta double échantillonnage (DDS) sont utilisés comme techniques de réduction du bruit. Un montage optique expérimental est utilisé pour caractériser les performances de l'imageur, et nous avons obtenu un gain en conversion de 7,3 uV/e-, une capacité de jonction de la photodiode de 22 fF, un bruit de lecture de 324,5 uV, ce qui équivaut à 45 électrons, et une gamme dynamique de 50,5 dB. Les avantages de l'ACS et NCDS-DDS sont observées dans le niveau faible de FPN du pixel et de la colonne, avec une valeur de 0,09% et 0,06% respectivement. Le travail présenté dans cette thèse est une première étape vers l'objectif de développer une plateforme entièrement intégrée SPR pour biocapteurs, incorporant source de lumière, l'interface SPR, canal microfluidique, les éléments d'optique et imageur CMOS
This dissertation presents the design and implementation of a CMOS imager for use in integrated biosensors based on Surface Plasmon Resonance. First, the optimal conditions for plasmon resonance in a CMOS/Post-CMOS compatible interface are obtained by COMSOL modelling. Second, a 32x32-pixel CMOS-Active Column Sensor (CMOS-ACS) is implemented on 0.35 um CMOS technology. In a gold-water interface with prism excitation, it is found that for prisms showing refractive indexes of 1.55 and 1.46, optimal plasmon coupling is obtained for gold films with thicknesses of 50 and 45 nm respectively. Under these conditions, approximately 99.19% and 99.99% of the incident light's energy is transferred to the surface plasmon for both prism respectively, provided that the incident light, with a wavelength of 633 nm, arrives with incidence angles of 68.45° and 79.05° respectively. It is also obtained that a change of 10-4 RIU in the refractive index of the dielectric medium, produces a change of 0.01° in the plasmon resonance angle, which under a light intensity modulation scheme produces a change of 0.08% in the reflected light's energy reaching the photodetector. Concerning the CMOS imager, a n-well/p-substrate photodiode is selected as the photosensing element, due to its low junction capacitance, which results in high efficiency and high conversion gain compared to the n-diff/p-substrate photodiode. Computer simulations with Cadence and Silvaco produced a junction capacitance of 31 fF and 135 fF respectively. The imager's pixel is based on a three-transistor (3T) configuration and shows a fill factor of 61%. The readout circuitry employs an Active Column Sensor (ACS) technique to reduce the Fixed Pattern Noise (FPN) associated with traditional Active Pixel Sensors (APS). Additionally, Non-Correlated Double Sampling (NCDS) and Delta Double Sampling (DDS) are used as noise reduction techniques. An experimental optical setup is used to characterize the performance of the imager, obtaining a conversion gain of 7.3 uV/e-, a photodiode junction capacitance of 21.9 fF, a read noise of 324.5 uV, equivalent to ~45 e- and a dynamic range of 50.5 dB. The benefits of ACS and NCDS-DDS are observed in the low pixel and column FPN of 0.09% and 0.06% respectively. The work presented in this thesis is a first step towards the goal of developing a fully integrated SPR-biosensing platform incorporating light source, SPR interface, microfluidic channel, optical elements and CMOS imager

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27

Stegmann, Darren Edward. "The investiation into the synthesis of 2,5-Diphenyloxazole in Streptomyces polyantibioticus SPR." Master's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/13421.

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Includes bibliographical references.
As part of an antibiotic-screening programme, an actinomycete, Streptomyces polyantibioticus SPRT, was isolated from soil collected from the banks of the Umgeni River, KwaZulu-Natal Province, South Africa. It exhibited antibiosis against M. tuberculosis H37RvT, prompting interest in its antibiotic production. An antibiotic produced by S. polyantibioticus SPRT was isolated and its structure determined by nuclear magnetic resonance (NMR) and X-ray crystallography to be 2,5- diphenyloxazole (DPO). Of great interest is the independent confirmation of the antibiotic activity of DPO and extension of the data to show activity against non-replicating persistent cells of M. tuberculosis. It seems likely that 2,5-DPO is synthesized non-ribosomally by S. polyantibioticus SPRT. It is proposed that DPO is synthesised from the starting units of benzoic acid and -hydroxyphenylalanine or phenylalanine, undergoing peptide bond formation followed by cyclization and decarboxylation to form DPO.

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Boulade, Marine. "Imagerie SPR optimisée en résolution pour l'étude et la détection de bactéries." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAS004/document.

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L’étude, la détection et l’identification de pathogènes est une problématique majeure pour la sécurité alimentaire et la médecine. Cependant, les pathogènes bactériens présents à de faibles concentrations nécessitent souvent une période de plus de 36h pour être identifiés par les méthodes standards. Ce délai est extrêmement contraignant pour des domaines où la rapidité du diagnostic est un facteur clé. Il y a donc une forte demande pour le développement d’outils pour mieux comprendre le comportement bactérien et ainsi développer des techniques de détection plus rapides et plus performantes.Les systèmes d’imagerie SPR sont largement utilisés pour l’analyse d’interactions moléculaires, car ils permettent une mesure en parallèle, en temps réel et sans marquage, tout en étant faciles d’utilisation et compatibles avec des milieux complexes. Cette technique a montré son efficacité pour l'étude et la détection de bactéries en utilisant les interactions moléculaires avec les anticorps, mais les délais de détection restent pénalisants.Dans ce contexte, un nouveau système d’imagerie permettant l’étude et la détection spécifique de pathogènes bactériens performant est développé en mettant à profit les avancées récentes en imagerie SPR optimisée en résolution. Notre système permet d'améliorer les temps de détection de pathogènes en milieux modèles grâce à sa capacité à détecter des bactéries individuelles. Il peut également être utilisé pour l'étude de l'interaction entre bactéries et surfaces spécifiques. Des premiers tests montrent que notre instrument est capable de caractériser le comportement bactérien de plusieurs souches bactériennes en interaction avec des surfaces fonctionnalisées par des espèces chimiques différentes
The study, detection and identification of pathogens is a major issue for food safety and medicine. However, bacterial pathogens present at low concentrations often require a period of more than 36 hours to be identified by standard methods. This delay is extremely constraining for areas where rapid diagnosis is a key factor. There is therefore a strong demand for the development of tools to better understand bacterial behavior and thus develop faster and more efficient detection techniques.SPR imaging systems are widely used for the analysis of molecular interactions, as they allow parallel, real-time and unlabeled measurement, while being easy to use and compatible with complex media. This technique has proven effective in the study and detection of bacteria using molecular interactions with antibodies, but detection times remain penalizing.In this context, a new imaging system allowing the study and specific detection of high-performance bacterial pathogens is being developed, taking advantage of recent advances in SPR imaging optimized in resolution. Our system improves pathogen detection times in model environments through its ability to detect individual bacteria. It can also be used to study the interaction between bacteria and specific surfaces. Initial tests show that our instrument is capable of characterizing the bacterial behaviour of several bacterial strains in interaction with surfaces functionalized by different chemical species

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29

Gharbi, Tasnim. "Bicouches Cuivre/oxyde : propriétés optiques, géométriques et structurales, énergie d’activation et SPR." Electronic Thesis or Diss., Troyes, 2022. http://www.theses.fr/2022TROY0009.

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L'objectif de cette thèse est de déterminer conjointementles épaisseurs et la permittivité relative de bicouches de Cuivre et d’oxyde à partir de mesures d’absorbance. Les hypothèses sur le type d’oxyde et les modèles d’inclusion d’air sont comparées, mises en œuvre et exploitées. Les meilleurs modèles en terme de qualité d’ajustement aux données expérimentales sont reliés à la structure des matériaux. Ce problème inverse est résolu en utilisant des métaheuristiques : PSO (Particle Swarm Optimization), ABC (Artificial Bee Colony) et EM (EvolutionaryMethod) qui sont comparées. Ces méthodes sont hybridées avec les méthodes du gradient et de Nelder-Mead. Les résultats obtenus sont utilisés pour évaluer et discuter l’énergie d’activation de l’oxyde de cuivre et pour étudier les propriétés d’un capteur SPR (Surface Plasmon Resonance) utilisant ce type de bicouche Cuivre/Oxyde
The main purpose of this thesis is to determine simultaneously the thicknesses and the relative permittivity of copper and oxide bilayers from absorbance measurements. We compare and analyze the assumptions on oxide type and air inclusion models. We discuss the best models in terms of goodness off it to experimental data to provide the structure of the materials. We solve this inverse problem by using metaheuristics:PSO (Particle Swarm Optimization), ABC (Artificial Bee Colony) and EM (Evolutionary Method). We compare these methods including hybridization with the gradient and Nelder-Mead methods. We use the results obtained to evaluate and discuss theactivation energy of copper oxide and to study theproperties of an SPR (Surface Plasmon Resonance) sensor using this type of copper/oxide bilayer

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30

Sevajol, Marion. "Caractérisation structurale et biophysique de Elmo1 et des interactions avec son partenaire." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00875173.

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Les protéines eucaryotes Elmo (Engulfment and Cell Motility) forment une famille de régulateurs conservés qui jouent un rôle central dans les processus biologiques reposant sur le remodelage du cytosquelette d'actine comme la phagocytose et la migration cellulaire et régulé par les GTPases de la famille Rho. Les protéines Elmo régulent la fonction des protéines Dock (Downstream of Crk), qui sont des Facteurs d'Echange de Guanine (GEF) atypiques pour les GTPases Rac1 et Cdc42. Le mécanisme de régulation connu à ce jour, repose sur l'interaction entre les 200 résidus C-terminaux d'Elmo et les 180 premiers résidus N-terminaux de Dock. Cependant, le rôle précis des différents domaines et motifs identifiés dans ces régions n'est pas encore défini. En effet, les données fonctionnelles, biochimiques et structurales rapportées à ce jour semblent contradictoires quant à la contribution de l'extrémité C-terminale d'Elmo qui comprend un motif polyproline et le domaine SH3 N-terminal de Dock. Nous avons donc étudié la contribution de l'extrémité C-terminale de Elmo1 à l'interaction entre Elmo1 et le domaine SH3 de Dock1 en utilisant notamment la résonance plasmonique de surface. Nos données démontrent la capacité du domaine SH3 de Dock1 à interagir avec Elmo1, indépendamment de l'extrémité C-terminale contenant le motif polyproline. Toutefois, la présence de cette région conduit à une augmentation significative du temps de demi-vie du complexe Elmo1/Dock1. En parallèle, des expériences de diffusion des rayons X aux petits angles nous ont permis de déterminer des enveloppes tridimensionnelles de la protéine Elmo1. Ces données nous permettent ainsi de proposer un premier modèle à basse résolution dans lequel nous localisons les parties N et C-terminales de Elmo1. De façon surprenante cette étude semble indiquer un changement de conformation de la région N-terminale de Elmo1 ainsi qu'une interaction possible de cette même région avec le domaine SH3 de Dock1.

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Jarske, André Oliveira Silva. "Modificação eletroquímica da superfície de filmes finos de ouro SERS e SPR ativos." reponame:Repositório Institucional da UFS, 2011. https://ri.ufs.br/handle/riufs/1087.

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Thin metal films have attracted much interest because they provide a way to produce surface plasmon resonance (SPR) in the Kretschmann configuration. This technique is a very sensitive for determining small changes at the interface between a metallic layer and a dielectric medium, and the metals generally used are silver and gold once their surface plasmon resonances are located in the visible range. Thin films of gold, due their stability and diversity applications, have been extensively studied by electrochemistry, surface enhanced Raman spectroscopy (SERS) and techniques of Microscopic such as AFM and STM. The Raman technique has been used to the analysis of organics compounds in determined system. However, in very low concentration levels is inefficient due to weak signal or interference from noise. A developed method to markedly increase the signal of a species presented at many levels is the SERS. One of the major considerations for the formation of a SERS-active surface is surface roughness, and this has been realized by various ways. In the present work, we analyzed the efects of various oxidation-reduction cycles (ORCs) on the surface of the thin films of gold using the techniques of cyclic voltammetry, microscopy, UV-Vis spectroscopy and SPR, which will be used to evaluate the efficiency of electrochemically modified substrates as SERS and SPR active. Initially, the film was cycling in a solution of H2SO4 to remove impurities from the surface. After this procedure, the 50 nm and 100 nm thick gold films, deposited on a glass substrate, were subjected to a series of ORCs in a solution of H2SO4 containing 0,005 M KCl electrolyte. As the number of ORCs is increased, the roughness of the film increased. We used techniques of microscopy, Spectroscopy UV-Vis, Resonance Plasmon Surface and Cyclic Voltammetry to characterize the surface of the film as a function of roughness. A “home − made” SPR system based on the configuration of Kretschmann was utilized for analyzed the changes provoked in surface film before and after the electrochemically modified. The medium size of the gold islands deposited was analyzed for Atomic Force Microscopy (AFM) and Scanning Tunneling Microscopy (STM). This same metallic film, after passing for oxidation processes and reduction, was used to obtain a spectrum SER using an organic molecule the 2-thiouracil adsorbed on the surface of the film. The results observed for AFM, STM and cyclic voltammetry shows that surfaces electrochemically modified increase the roughness, and that the changes modified o depth of the signal SPR. These change provoked electrochemistry after various ORC improve significantly the Raman sign of molecules adsorbed on the surfaces of the metallic films. Finally, we conducted an evaluation of the roughness factor obtained through the techniques of AFM, STM and cyclic voltammetry. _______________________________________________________________________________________ RESUMO: Filmes finos metalicos tem despertado muito interesse devido a possibildade de produzir Ressonancia de Plasmons de Superfıcie (SPR) utilizando uma configuracao de Kretschmann. Esta tecnica e muito sensıvel na determinacao de pequenas mudancas na interface entre uma camada metalica e um meio dieletrico, e os metais usados geralmente sao prata e ouro, uma vez que a ressonancia de plasmon da superfıcie desses metais esta localizada na regiao do visıvel. Esses filmes, devido a sua estabilidade e diversidade de aplicacoes, tem sido extensivamente estudados por tecnicas eletroquımicas, espectroscopia Raman intenficada por superfıcie (SERS) e por tecnicas de microscopia tais como o AFM e STM. A Espectroscopia Raman tem sido utilizada para a analise de compostos organicos em determinados sistemas. No entanto, em sistemas que possuem concentracoes muito baixas, o sinal Raman e extremamente fraco e ineficiente, ou sofre interferencias de ruıdos. Um dos metodos desenvolvidos para aumentar significativamente o sinal de uma especie adsorvida sobre uma superfıcie metalica em varios nıveis e o SERS. Uma das consideracoes importantes para a formacao de um substrato SERS ativo e a rugosidade da superfıcie, e a obtencao dessas superfıcies tem sido realizado de diversas maneiras. No presente trabalho, analisamos o efeito de diferentes ciclos de oxidacao-reducao (ORCs) sobre a superfıcie de filmes finos de ouro, utilizando as tecnicas de voltametria cıclica, microscopias, espectroscopia UV-Vis e SPR, que serao utilizadas para avaliar a eficiencia dos substratos modificados eletroquimicamente como SERS e SPR ativos. Inicialmente, o filme e ciclado em uma solucao de H2SO4 para remover as impurezas da superfıcie. Apos este procedimento, os filmes com espessuras de 50 e 100 nm, depositados sobre um substrato de vidro, foram submetidos a uma serie de ORCs em uma solucao de H2SO4.

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32

Brian, Björn. "Microarray Technology for Kinetic Analysis of Vesicle Bound Receptor-Ligand Interactions." Thesis, Linköping University, The Department of Physics, Chemistry and Biology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8739.

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A proof-of-concept for a novel microarray used to study protein-ligand interaction in real-time using label-free detection is presented. Many of todays commercially available instruments lack the ability to immobilize membrane proteins. At the same time, the pharmaceutical industry develops drugs directed towards membrane-bound receptors. The need to study drug-target kinetics and to be able to screen for new medical substances is high. To study the biomolecular interactions in real-time, imaging surface plasmon resonance (iSPR) is used. A patterned sensor surface with hydrophobic barriers assisting in the piezodispensing of NeutrAvidin with complex-bound biotin-ssDNA is created. Histidine-tagged proteins are immobilized at the vesicle surface using divalent nitrilotriacetic acid. The concept of the vesicle immobilization, the protein-binding to vesicles and the protein-ligand interaction is initially studied using a Biacore instrument. The dissociation of the ligand IFNα2 from its receptor ifnar-2 (wt) are in accordance with the literature. In the imaging SPR experiments, it is found that the dissociation of IFNα2 from the ifnar-2 (wt) receptor is slower than expected, probably due to rebinding of the ligand. It is also found that imidazole is needed to avoid vesicle-vesicle interaction. The immobilization of proteins had to be done on-line i.e. when the vesicles were bound to the surface. Depending on the mixture of receptors at the vesicle surface the affinity for the ligand was changed. The results achieved were reproducible.

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33

Han, Jeongwoo. "Development of an electronically tunable ultra-wideband radar imaging sensor and its components." Texas A&M University, 2003. http://hdl.handle.net/1969.1/3904.

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Novel microwave transmitter and receiver circuits have been developed for implementing UWB (Ultra-Wideband) impulse radar imaging sensor operating in frequency band 0.2 to 4 GHz. with tunable operating frequency band. The fundamental system design parameters such as the required transmitting pulse power and the pulse duration were estimated for a presumed specific application, the pavement assessment. The designed transmitter is the tunable monocycle pulse generator with tuning capability for the output pulse duration from 450- to 1200- ps, and has relatively high transmitting pulse power from 200 to 400 mW. Tuning of the pulse duration was implemented by novel PIN diode switch configuration and decoupling circuit, and boosting of transmitting pulse power was made possible by using a high power pulse driving circuit and SRD coupling circuit. The synchronous sampling receiver system was designed by using the integrated sampling mixer and two reference clock oscillators placed in the transmitter and receiver respectively for timing control. A novel integrated CSH (Coupled-Slotline Hybrid)sampling mixer has been developed along with the design of the strobe pulse generator appropriate for the impulse radar system. The integrated sampling mixer has unprecedented conversion loss of 2.5 dB for the pulse signal, bandwidth 5.5 GHz, and dynamic range 50 dB. The introduced UWB LNA (Low Noise Amplifier) design operating up to 4 GHz should be useful for weak signal detection applications. The design of the UWB microstrip quasi-horn antenna was optimized for short pulse transmission with respect to the input return loss and the pulse stretching effect. For signal detection in the signal processing stage, the background subtraction technique and B-scan data format were used. A novel signal monitoring technique was introduced in the signal processing to compensate the frequency modulation effect of the reference clock. The test results for the complete system with respect to some sample multi-layer structures shows good receiving pulse waveform with low distortion, enough pulse penetration depth for 13Â pavement sample structure, and minimum 1-in of range resolution.

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34

Pearson, David Scott. "Reversible Photoregulation of Binding of the Serine Protease α-Chymotrypsin to a Functional Surface." Thesis, University of Canterbury. Chemistry, 2007. http://hdl.handle.net/10092/2508.

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This thesis presents the first example of reversible photoregulation of the binding of a protease, α-chymotrypsin, to a surface. A modular approach is used involving the azobenzene photoswitch group, a surface linker and an enzyme binding group. This approach is designed to be easily extended to the photoregulation of binding of other proteases to surfaces by use of enzyme binding groups selective to these proteases. Chapter one gives a brief outline of some of the important areas involved in to this work, including molecular switches, proteases and surface modification. Chapter two describes the synthesis of azobenzene-containing boronate esters designed as photoswitch inhibitors of α-chymotrypsin. Boronate esters were prepared containing the aminophenylboronate group or the peptidomimetic borophenylalanine group for enzyme binding and a range of substituents designed for enzyme affinity and/or surface attachment. Syntheses primarily involved peptide coupling reactions and azobenzene formation by condensation of nitrosobenzenes and anilines. Coupling reactions were successfully carried out using EDCI or isobutyl chlorofomate in several cases where other reagents gave unacceptable decomposition. Chapter three describes the syntheses and HPLC stability studies of derivatives of a noncovalent α-chymotrypsin inhibitor. Several dipeptide-based compounds containing either an amide group for surface attachment or an azobenzene group for photoswitching were prepared, primarily using peptide coupling reactions. Each compound was incubated with α-chymotrypsin to assess its stability, and all were found by HPLC monitoring to be stable to α-chymotrypsin catalysed hydrolysis. Chapter four describes syntheses of azobenzene-containing trifluoromethylketones and α-ketoesters designed as photoswitch inhibitors of α-chymotrypsin. Trifluoromethylketones/α-ketoesters containing amine groups for surface attachment were prepared, primarily using peptide coupling reactions, but could not be isolated due to the incompatibility of the electrophilic ketone and primary amine groups. Trifluoromethylketones/α-ketoesters containing terminal alkynes for surface attachment were prepared either by the attachment of an alkyne substituent group to a symmetrical azobenzene core or by Pd-catalysed reaction of a protected alkyne with an azobenzene having a halide substitutent. Chapter five describes syntheses of sulfur-containing surface linkers for use in surface attachment of the photoswitch inhibitors described in chapters 2-4. A range of compounds containing disulfide or protected thiol groups for surface attachment and azide or carboxylic acid groups for inhibitor attachment were prepared. Syntheses primarily involved coupling of functionalised alcohols/amides to carboxylic acid-containing disulfides/thioacetates. Selected linkers were attached to azobenzenes by amide coupling or azide-alkyne cycloaddition for surface attachment, photoswitching and/or enzyme assay. Azide-alkyne cycloaddition yields were initially poor, but were improved by use of stoichiometric amounts of copper catalyst. Chapter six describes UV/vis photoisomerisation studies and enzyme assays carried out to assess enzyme photoswitching of the compounds described in chapters 2-5. The trifluoromethylketones and α-ketoesters described in chapter 4 gave the best results, with moderate inhibition of α-chymotrypsin (µM affinity constants) and up to 5.3 fold changes in inhibition on UV/vis irradiation. Many of the boronate esters described in chapter 2 were found to inhibit α-chymotrypsin, but were somewhat unstable to irradiation. The dipeptide-based compounds described in chapter 3 were inactive against α-chymotrypsin. Good photoisomerisation was obtained for an azobenzene containing a symmetrical disulfide surface linker and poor photoisomerisation was obtained for an azobenzene containing a lipoic acid surface linker. Chapter seven describes surface attachment of selected photoswitch inhibitors and studies of photoregulated enzyme binding to the resultant functional surfaces. Self assembled monolayers (SAMs) of disulfides were formed on gold surfaces and characterised by electrochemistry and contact angle measurements. Binding of α-chymotrypsin to SAMs containing a photoswitch inhibitor was detected by quartz crystal microbalance (QCM), but was found to be largely irreversible. An alkyne-containing photoswitch inhibitor was attached to a surface plasmon resonance (SPR) chip in a two step procedure involving generation of an azide modified surface followed by azide-alkyne cycloaddition. Binding of α-chymotrypsin to the resultant modified surface was detected by SPR and successfully regulated by UV/vis irradiation. Chapter eight provides conclusions for the work described in this thesis and suggests future directions. Chapter nine gives experimental details for the work described in this thesis.

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Vindas, Yassine Karim. "Résonance plasmon et développements instrumentaux vers la conception de biopuces et biocapteurs innovants." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY091/document.

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Ce travail de thèse porte sur la conception d’un « laboratoire-sur-fibre » original dédié à l’analyse moléculaire à distance, sans marquage et in vivo compatible dans l’avenir avec les examens endoscopiques et dédié à l’assistance aux diagnostiques. Notre approche est basée sur l’utilisation de faisceaux de fibres microstructurés. Lorsqu’ils sont correctement conçus et recouverts d’une couche d’or, ces assemblages de fibres présentent des propriétés plasmoniques intéressantes. Dans un premier temps, le modèle numérique utilisé pour atteindre une meilleure compréhension des phénomènes physiques impliqués dans l’optimisation de la sensibilité des capteurs est expliqué. Les simulations, basées sur l’optique géométrique, ont été utilisées pour optimiser la géométrie des pointes et l’épaisseur de la couche d’or dans le but d’améliorer les performances analytiques et permettre ainsi des détections d’interactions biochimiques. Le processus de fabrication des capteurs est ensuite expliqué depuis leur structuration par gravure chimique effectuée à l’ISM (Bordeaux) jusqu’à leur métallisation réalisée au CEA Grenoble. Une comparaison entre les comportements théoriques et expérimentaux et alors menée pour comprendre l’influence de l’hétérogénéité du dépôt d’or et des surfaces gravées sur la sensibilité optique. Ces propriétés optiques sont ensuite exploitées jusqu’à la preuve de concept d’analyses biochimiques déportées. Cette étape a été réalisée en deux temps : d’abord la sensibilité à l’indice local a été démontrée en détectant l’adsorption d’une couche organique auto-assemblée et ensuite un suivi de l’interaction spécifique entre deux brins d’ADN complémentaires a été effectué. Le manuscrit s’achève par une analyse des aspects plus complexes liés à la nature peu multimodale des fibres présentes dans le faisceau. La théorie des guides d’ondes est alors utilisée pour expliquer l’influence du caractère modal de la propagation de la lumière sur les réponses des fibres optiques
This Ph.D. thesis focuses on the design of an original “lab-on-fiber” tool for remote, label-free in vivo molecular analysis that could be dedicated in the future to endoscopic diagnosis. Our approach is based on functionalized microstructured optical fiber bundles. When appropriately designed and covered by a gold layer, those fibers exhibit interesting plasmonic properties. First, the numerical model used to reach a better understanding of the physical phenomena involved in the optimization of the sensor’s sensitivity is explained. The simulations based on ray optics were then used to optimize the fiber tip geometry and gold coating thickness to enhance the analytical performances and ultimately allow biochemical detections. The fabrication process of the sensor is then explained going from the chemical etching done by the ISM team (Bordeaux) to the metallization of the tips performed at the CEA Grenoble. A comparison between theoretical and experimental behaviors is then conducted to assess the influence of the heterogeneity of both the gold deposit and the etched surfaces on the optical sensitivity. Afterwards, we take advantage of those optical properties to perform remote biochemical analysis. This was achieved in two steps: we first proved that our sensor was sensitive to local optical index variations by detecting the adsorption of a thin self-assembled organic layer and ultimately a specific interaction between two complementary DNA strands was monitored. The last part of this work tackles the more difficult aspects of the few-modes fibers composing the bundle. Waveguide theory is then used to explain the influence of the modal characteristics of light propagation on the optical fibers responses

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Le, Du Julie. "Développement d'antagonistes des récepteurs CXCR2 contre les pathologies angiogéniques oculaires et le cancer." Electronic Thesis or Diss., Université Côte d'Azur, 2024. http://www.theses.fr/2024COAZ5067.

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L'angiogenèse, ou processus de formation de nouveaux vaisseaux sanguins, joue un rôle majeur dans la progression de nombreux cancers et diverses pathologies oculaires. Les récepteurs aux chimiokines CXCR2 sont impliqués dans ces processus en médiant la prolifération cellulaire, l'inflammation et la formation de nouveaux vaisseaux sanguins. Le but de cette thèse a donc été de développer des antagonistes des récepteurs CXCR2 pour inhiber ces mécanismes pathologiques, et en particulier l'angiogenèse pathologique tumorale et oculaire. Sur la base de recherches antérieures, nous avons étudié de nouveaux analogues de N,N'-diarylurée comme inhibiteurs de la voie ELR+CXCL-CXCR2, pour le traitement du cancer. Deux séries d'analogues ont été synthétisées afin d'étudier la relation structure-activité et d'optimiser un composé lead. Des évaluations sur des lignées cellulaires de cancer du rein, de la tête et du cou et de mélanomes uvéaux, ainsi que sur des cultures sphéroïdes 3D ont identifié un composé lead optimisé, montrant une inhibition significative de l'invasion, de la migration et de la néo-angiogenèse. De plus, des études de pharmacologie, de pharmacodynamie et de polymorphisme ont été réalisées. Dans le cadre des pathologies oculaires angiogéniques, le développement d'une seconde famille de composés a été poursuivi, avec notamment l'étude de nouvelles voies de synthèse en vue d'une montée en échelle pour une future production industrielle et des études de formulation afin de réaliser des préparations de principes actifs sous forme de collyre. Enfin, une nouvelle série de composés à visée anticancéreuse a été conçue et une voie de synthèse a été développée pour obtenir une première série d'analogues. L'évaluation des activités biologiques de ces composés a permis de dégager une relation de structure-activité préliminaire
Angiogenesis, the process of forming new blood vessels, plays a crucial role in the progression of various cancers and ocular diseases. CXCR2 chemokine receptors are implicated in these processes by mediating cell proliferation, inflammation, and the formation of new blood vessels. This thesis aims to develop CXCR2 receptor antagonists to inhibit these pathological mechanisms, particularly pathological tumor and ocular angiogenesis. Based on previous research, we investigated new N,N'-diarylurea analogues as inhibitors of the ELR+CXCL-CXCR2 pathway for cancer treatment. Two series of analogues were synthesized to study the structure-activity relationship and to optimize a lead compound. Evaluations on renal, head and neck cancer, and uveal melanoma cell lines, as well as on 3D spheroid cultures, identified an optimized lead compound showing significant inhibition of invasion, migration, and neo-angiogenesis. Additionally, pharmacology, pharmacodynamics, and polymorphism studies were conducted.In the context of ocular angiogenic diseases, the development of a second family of compounds was pursued, including the study of new synthetic routes for scaling up for future industrial production and formulation studies to create active ingredient preparations in the form of eye drops.Finally, a new series of anticancer compounds was designed, and a synthetic route was developed to obtain a first series of analogues. The evaluation of the biological activities of these compounds allowed the establishment of a preliminary structure-activity relationship

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37

Gelinsky-Wersing, Dagmar. "Kinetisches Modell für die Prozessanalyse von Displacement-Assays mit mono- und bivalenten Antikörpern." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-230751.

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Molecular and functional analysis of small molecule binding to protein can provoke insights into cellular signaling and regulatory systems as well as facilitate pharmaceutical drug discovery. In label free small molecule detection the displacement assay format can be applied. This assay format comprises the displacement of receptor molecules bond to immobilized ligand by a competition reaction with ligand in solution. This is beneficial because displacement of high molecular receptors is detected compared to low molecular ligand as in classical binding analysis therefore potentially lowering the method detection limit. It was hypothesized that with choosing appropriate measuring methods and theoretical modeling reaction rate constants can be determined separately in every kinetic stage of the assay format. Herein elucidating the dominant valence of antibody antigen binding in the established assay was of great importance. Using the Influenza Hemagglutinin (HA) peptid binding to mono or bivalent Anti-Hemagglutinin peptide antibody displacement assay formats could be established. The exact time resolved analysis of binding and dissolution of ligand HA and Anti-Hemagglutinin peptide antibody was achieved with surface plasmon resonance (SPR) spectroscopy. Mathematical models could be developed from kinetic equations of ligand binding to mono or bivalent antibody. With this, an accurate simulation of the SPR results was reached. The simulation plot had to be exactly adjusted to the SPR results to determine all kinetic rate constants defining ligand and receptor binding kinetics. Large variations in receptor concentration gave almost identical rate constants in binding; this proves the quality of SPR measurements and demonstrates consistence between measurement, simulation, and binding model. Maximum decline of SPR response could be used to determine ligand concentrations in analyte. Displacement dependence from antigen concentration was found to be exponential and was explained by rebinding. Kinetic data and models could be transferred for the simulation of almost stationary displacement assay formats realized with impedance and fluorescence spectroscopy. With the obtained results it was possible to detect the displacement of the bacterial signaling autoinducer AI-2 by a displacement assay format using periplasmic binding protein LuxP as receptor. Concluding it can be said that the hypothesis could be proved and the obtained results can facilitate the use of displacement assay formats in biosensing. Displacement assay formats should be especially interesting in small molecule detection and in compact integrated mass sensitive sensor designs suitable as mobile sensors in outdoor screening
Die Analyse des Bindungsverhaltens niedermolekularer Liganden an Proteine ist für die Aufklärung von biologischen Regulationssystemen oder bei der Suche neuer medizinischer Wirkstoffe von Wichtigkeit. Ein markierungsfreies Detektions¬prinzip zur Erfassung niedermolekularer Liganden ist die Displacement- oder Replacement-Methode. Bei dieser tritt die Bindung des Rezeptors an den immobilisierten Liganden mit der Bindung an freien Liganden in Konkurrenz, sodass anstelle der niedermolekularen Liganden die hochmolekularen Rezeptoren detektiert werden können. In dieser Arbeit wurde von der Hypothese ausgegangen, dass durch die Auswahl geeigneter Messverfahren und der zugeordneten Modellierung die einzelnen kinetischen Stadien des Displacements separat zur Bestimmung der kinetischen Konstanten der Displacementprozesse genutzt werden können. Dabei sollte unter anderem auch eine Aussage über die dominierende Valenz der Antigen-Antikörper-Bindung erreicht werden. Hierzu wurden auf der Basis des Modellsystems Hämagglutinin-Peptid/ Hämagglutinin-Antikörper Displacement-Assays mit mono- und bivalenten Anti-körpern entwickelt, anhand derer eine genaue zeitaufgelöste Analyse des Bindungs- und Ablösungsverhaltens vom Liganden HA an den Anti-HA-Antikörper (Rezeptor) mittels Oberflächenplasmonenresonanz(SPR)-Spektroskopie erzielt wurde. Ausgehend von den Reaktionsgleichungen zwischen Liganden und mono- und bivalenten Rezeptoren wurden mathematische Modelle entwickelt, die eine exakte Simulation der SPR-Ergebnisse ermöglichten. Durch genaues Anpassen der Simulationsplots an die Messplots konnten alle Ratenkonstanten, die die Kinetik der Reaktionen zwischen Liganden, Rezeptoren und ihren Komplexen bestimmen, ermittelt werden. Da auch für eine große Variation der Rezeptorkonzentrationen in der Analytlösung nahezu identische Werte für die Ratenkonstanten erhalten wurden, ergeben Messungen und Simulationen ein konsistentes Bild der Anbindungskinetik und bestätigen die Qualität der Messungen. Aus Messungen des maximalen Responsabfalles kann die Konzentration der freien Antigene beim Displacement ermittelt werden. Man findet eine exponentielle Abhängigkeit des Displacements von der Konzentration der freien Antigene, die sich durch den sogenannten „Rebindingeffekt“ erklären lässt. Die gewonnenen kinetischen Daten und entwickelten Modellierungsverfahren konnten zur Simulation quasistationärer Detektionsverfahren, die mit Fluoreszenz- und Impedanzspektroskopie durchgeführt wurden, erfolgreich angewandt werden. Die erzielten Erkenntnisse konnten auf ein wissenschaftlich herausforderndes biologisches System (LuxP/AI2) angewandt werden, bei dem das niedermolekulare Signalmolekül AI2 über ein Displacementassay detektiert wurde. Dieses System ermöglicht einen Einblick in die Intra- und Interspezieskommunikation bei Bakterien. Insgesamt zeigt sich, dass die hier formulierte Hypothese als bewiesen angesehen werden kann. Die in dieser Arbeit gewonnenen Erkenntnisse eröffnen verschiedene Einsätze der Displacementmethode in der Biosensorik. Insbesondere lassen sich damit kleine Moleküle markierungsfrei quantitativ bestimmen, ohne hoch präzise Analysengeräte einsetzen zu müssen. Damit ergibt sich die Möglichkeit, sehr kompakte integrierte massensensitive Sensoren, die nicht die Empfindlichkeit hochempfindlicher SPR-Spektrometer erreichen, zur Detektion kleiner Moleküle einzusetzen. Dies ist besonders für mobile Anwendungen von Interesse

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38

Salazar, Soto Arnoldo. "Conception et implémentation d'un imageur CMOS de colonne actif pour capteurs basés sur SPR." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-01062484.

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Cette thèse présente la conception et la mise en œuvre d'un imageur CMOS pour être utilisé dans biocapteurs intégrés basés sur Résonance Plasmonique de Surface (SPR). Tout d'abord, les conditions optimales pour la résonance plasmon dans une interface compatible CMOS / post-CMOS sont obtenus par modélisation avec COMSOL. Deuxièmement, un imageur CMOS de Colonne Actif (CMOS-ACS) du 32x32 pixels est mis en œuvre sur une technologie CMOS 0,35 um. Dans une interface d'or-eau avec une excitation de prisme, on constate que pour les prismes avec des indices de réfraction de 1,55 et 1,46, le couplage optimal avec le plasmon est obtenu pour des films d'or d'une épaisseur de 50 et 45 nm, respectivement. Dans ces conditions, environ 99,19% et 99,99% de l'énergie de la lumière incidente est transférée à le surface plasmon pour les deux prismes respectivement, à condition que la lumière incidente, avec une longueur d'onde de 633 nm, arrive avec un angle d'incidence de 68,45° et 79,05° respectivement. Il est également obtenu qu'un changement de RIU 10-4 de l'indice de réfraction du milieu diélectrique, produit un changement de 0,01 ° dans l'angle de résonance de plasmons qui, dans un schéma de modulation d'intensité de lumière produit une variation de 0,08% dans la lumière réfléchie au photodétecteur. En ce qui concerne le imageur CMOS, une photodiode n-well/p-substrate est choisi comme l'élément de photodétection, en raison de sa faible capacité de jonction, ce qui conduit à un rendement élevé et le gain de conversion élevé comparativement à une photodiode n-diff/p-substrate. Des simulations sur ordinateur avec Cadence et Silvaco produit une capacité de jonction de 31 FF et 135 fF respectivement. Le pixel de l'imageur est basé sur une configuration à trois transistors (3T) et présente un facteur de remplissage de 61%. Le circuit de lecture utilise une technique de capteur de colonne actif (ACS) pour réduire le bruit à motif fixe (Fixed Pattern Noise ou FPN en anglais) liée au le Capteur à Pixels Actif (APS) traditionnelle. En outre, Non-Corrélés Echantillonnage Double (Non-Correlated Double Sampling ou NCDS en anglais) et Delta double échantillonnage (DDS) sont utilisés comme techniques de réduction du bruit. Un montage optique expérimental est utilisé pour caractériser les performances de l'imageur, et nous avons obtenu un gain en conversion de 7,3 uV/e-, une capacité de jonction de la photodiode de 22 fF, un bruit de lecture de 324,5 uV, ce qui équivaut à 45 électrons, et une gamme dynamique de 50,5 dB. Les avantages de l'ACS et NCDS-DDS sont observées dans le niveau faible de FPN du pixel et de la colonne, avec une valeur de 0,09% et 0,06% respectivement. Le travail présenté dans cette thèse est une première étape vers l'objectif de développer une plateforme entièrement intégrée SPR pour biocapteurs, incorporant source de lumière, l'interface SPR, canal microfluidique, les éléments d'optique et imageur CMOS.

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39

Liang, Hao. "Data acquisition and analysis of a novel SPR biosensor using a laser line generator." Thesis, Högskolan i Gävle, Avdelningen för elektronik, matematik och naturvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-20037.

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40

Perry, Guillaume. "Contribution à la réalisation de dispositifs microfluidiques à base d’électromouillage pour la détection SPR." Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10104/document.

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Ces travaux de thèse ont porté sur l’étude de solutions originales pour limiter la biopollution dans des systèmes microfluidiques à base d'électromouillage (EWOD) couplés à un biocapteur à résonance de plasmons de surface (SPR). Deux approches complémentaires ont été étudiées. Dans un premier temps nous avons mis à profit la forte adsorption de protéines sur des nanofeuillets d'oxyde de graphène (GO): les caractérisations de mouillage de solutions contenant un mélange de GO et de protéines (albumine sérique bovine - BSA) ont permis de montrer que le GO maintenait en suspension les protéines en évitant leur adsorption sur la surface. Le résultat le plus remarquable obtenu concerne le déplacement par EWOD de BSA, à une concentration de 195ng/µL (pour 500ng/µL de GO), 30 fois plus que ce qu’il est possible de transporter sans GO. Nous avons montré que la présence des feuillets de GO n’altère pas l’activité enzymatique. Une autre solution a consisté à développer des surfaces superomniphobes (connues pour leur propriété d’auto-nettoyage) via un dépôt chimique de nanostructures d’oxyde de zinc (ZnO). Nous avons montré que certaines nanostructures de forme réentrante présentent des angles de contact supérieurs à 140°, des hystérésis inférieures à 20° pour des liquides de tensions de surface supérieures à 35mN/m. Pour finir, ces deux approches ont été validées pour l’application envisagée. L’interaction entre biomolécules et biodétecteur SPR a pu être validée (i) en contrôlant la désorption des protéines du GO par une solution basique, (ii) en réalisant des ouvertures dans les nanostructures de ZnO
This work reports on the study of original strategies to limit biofouling in Electrowetting-on-Dielectric (EWOD) based microfluidic devices coupled with a Surface Plasmon Resonance (SPR) biosensor. Two complementary approaches have been investigated. In the first part, we take advantage of the high adsorption capacity of graphene oxide (GO) for biomolecules: the wetting properties of a mixed solution containing Bovin Serum Albumine (BSA) and GO show that GO keeps proteins in suspension inhibiting their adsorption on the surface. The most important result concerns the EWOD motion of BSA droplet with a concentration of 195ng/µL (with 500ng/µL of GO). In this case, the BSA concentration is 30 times higher than the BSA concentration which can be displaced without GO. We show also that the presence of GO in the droplet does not alter the enzymatic activity of horseradish peroxidase (HRP) after GO/HRP displacement. The other developed solution consists in the development of superomniphobic surfaces (known for their self-cleaning properties) via chemical deposition of zinc oxide (ZnO) nanostructures. The chemically functionalized ZnO nanostructures display contact angles higher than 140° and hysteresis lower than 20° for liquids of surface tensions higher than 35 mN/m. To conclude, these two approaches have been validated for the targeted application. Interaction between biomolecules and the SPR biosensor can be realized (i) by controlling proteins’ desorption from GO in base solution, (ii) by making microapertures in ZnO nanostructured surfaces

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41

Bergström, Gunnar. "Exploring the SPR methodology for monitoring of critical attributes in toxicity testing and bioproduction." Licentiate thesis, Linköpings universitet, Teknisk biologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-73410.

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Analysis of biological components is central in bioprocess monitoring, process control, product quality control and cell based toxicity assaying. One of these themes that is pursued in this thesis is the use of biosensors for monitoring of molecular markers, exploiting the natural selectivity of biomolecules. Another is the use of glycoconjugates to monitor the activity of biomolecules in a flu vaccine process is studied and were the sensor is based on the concept of weak affinity giving fast response time for the sensor. A third theme is monitoring of cell cultures used for toxicity testing different protein markers is of interest. When developing biosensor surfaces for new antigens commercial preparations of antibodies are often used. In this work we have chosen to look at lactate dehydrogenase (LDH) and describe the preparation and characterisation of antibody used in biosensor surface development. The design of a sensor surface is important for the characteristics of a sensor. By binding antibodies in an oriented manner to the surface a better control of the properties of the antibodies is achieved. The demonstrated method also has the advantage of in situ purification and provides a flexible platform for antibody evaluation and sensor development. In one sentence this thesis explores the possibility of utilizing recognition elements of a biosensor surface. In particular, surface plasmon resonance (SPR) is used as the primary biosensing tool, however most findings in are relevant for other biosensors. Moreover, the thesis approaches existing bioanalytical impediments, such as purity and accessibility of the recognition elements on the sensor surface and preparation strategies to achieve this.

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Tai, Jiu-kai, and 戴久凱. "A CASCADED FORM OF SIDE-POLISHED SPR FIBER USED TO ENHANCE SPR EFFECT." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/gp2492.

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碩士
大同大學
光電工程研究所
95
The phenomenon of surface plasmon resonance is widely applied in the biological and chemical sensing for characterizing and quantifying biomolecular interactions. The traditional advantages of SPR detective method have high sensitive response, kinetic study in real-time, and label-free for biological sensing. Optical fiber sensor has the characteristics of small, low cost, and the same scheme on SPR. It is worthy to develop the fiber SPR sensor. A novel cascaded structure of a side-polished multi-mode SPR cascaded fiber sensor is presented. In our experiment we use a white light (halogens light) source to carry out the measurements and the results showed that the cascaded structure can enhance and improve the measurement sensitivity significantly. Besides, a laser diode operated at 690nm wavelength as the light source was applied to measure methanol, DI water, ethanol, 1-propanol, and 1-butanol solutions. The results show that in the case of two cascaded section of side-polished fibers in the refractive index range from 1.33 to 1.38 RI have almost 1.5 times sensitivity than the original fiber with single section, and almost twice sensitivity in the case of three cascade section of the side-polished fiber. Beside, a reflection structure had been also carried out for the same measurements. The reflection-type fiber SPR sensor enable we to realized the facility of probing measurement. .

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43

LISI, SAMUELE. "Novel approaches based on surface plasmon resonance biosensor for molecular diagnosis of Alzheimer's disease." Doctoral thesis, 2017. http://hdl.handle.net/2158/1080034.

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La tesi descrive nuove strategie di diagnostica molecolare della malattia di Alzheimer basate sulla tecnologia SPR. Nel lavoro vengono confrontati due tipi di recettori , uno di tipo commerciale (anticorpo) e uno opportunamente selezionato grazie alla collaborazione con l'Università Grenoble Alpes. L'uso di nanostrutture è inoltre investigato per migliorare le performances del sensore ottico sviluppato per l'analisi della proteina tau. - This thesis describes new analytical strategies for the detection of protein tau, one of the Alzheimer's disaese biomarker. The main technology used during the thesis is the Surface Plasmon Resonance. Two receptors were compared for their capability of tau detection. First of all combination between a commercial antibody and the use of nanostructures is described in the manuscript. Secondly aptamer selection (realized in collaboration with the Univeristy Grenoble Alpes) was realized by non- SELEX, giving rise to a new receptor for tau analysis.

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Chen, Shinn-Yuan, and 陳信源. "Investigation on ARROW-B SPR Chemical Sensors." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/19358544515011528928.

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碩士
國立交通大學
電子工程學系
85
A design of ARROW-B SPR chemical sensor for use in the field of environmentalmonitoring is presented. The use of an ARROW-B structure permits incorporationof a thick guiding region for efficient coupling to a single-mode fiber. In thisthesis, we present a rigorous model for the optical power transmittance of thistype of sensor. This model is used to determine the difference in normalizedoutput power between two sensing arms of the sensor, as a function of waveguide,metal film, buffer layer parameters. Our sensor is designed to operate in waterto detect low concentration pollution of water, and a high sensitivity for detectingchanges on the order of 10e-5 in the refractive index of analyte is achieved.

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Su, Chien Wei, and 蘇建維. "Enhanced Absorption by SPR for Solar Cell Application." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/66991037303996973966.

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碩士
國立臺灣大學
光電工程學研究所
95
Surface plasmon resonance (SPR) is a unique light-matter hybrid interaction that will transfer absorbed incident light energy into local enhanced electric field at the interface of metal and dielectric materials. It is of great interest for a variety of applications in metallic nanoparticles such as artwork [1], biosensor [2], data storage, SERS [3], nanolithography [4], therapy [5], NIR-blocked window [6], solar cell, and other researches on subwavelength optics [7]-[8]. The SPR in metallic nanoparticles (say, particle plasmon) can be analyzed by Mie theory [9]. The peak absorption wavelength of particle plasmon can be controlled by nanoparticles’ size, shape, spacing, and local dielectric environment [10]. In this thesis, we will describe an engineered enhancement of optical absorption in an organic photovoltaic cell via the excitation of SPR in spherical Au nanoparticles deposited on a device surface. We deposited gold nanoparticles with 5 nm in diameter on ITO (indium tin oxide) glass substrates and then coated poly (styrenesulfonate) / poly(2,3-dihydro-thieno-1,4-dioxin) (PEDOT) which can reduce the work function of metal atoms and poly [2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEHPPV) with Fullerene(C60) mixtures that work as p-type and n-type organic semiconductors, respectively. We work on both Mie theory simulation and experimental confirmation. Simulation results will help us know more about SPR phenomenon in our case that we can predict its resonance peak and how large enhancement it is over visible range. In experiment part, we do the I-V curve measurement and spectrum response. The enhancement in electromagnetic field absorption within a device results in increased photocurrent response in organic p-n junction diodes with gold nanoparticles over wavelength ranges. Compared with the same organic photovoltaic structures without gold nanoparticles, the proposed device shows about 40% power efficiency improvement under halogen light illumination. Furthermore, the enhancement peak occurs near 335nm. This result answers well to the prediction of simulation, which convince us SPR really works in organic solar cell. Finally, we introduce enhancement mechanism of electric field effect and heating effect. Because the mechanism has not been revealed clearly, we will investigate more about this topic in the future.

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Su, Ming-Chi, and 蘇明啟. "Advanced Structure Design for SPR Bio-sensor Device." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/23307704499866161903.

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碩士
國立臺灣大學
醫學工程學研究所
93
Surface Plasmon Resonance (SPR) is a novel optical sensing technique with advantages of label-free, high sensitivity, real-time monitoring, versatility (bio-chemistry reaction, concentration of molecule), and parallel detection. This research is focused on the improvement of system component , and we using the structure designs of 1D multilayer and 2D grating for enhanced performance. Based on the theory of optical admittance loci diagram, we designed a new asymmetric multilayer structure to replace traditional single gold layer. We applied the periodic refractive index change of two dielectric materials (TiO2/SiO2) combined with bimetallic design (gold/silver). SPR angle can be modulated to 61.52°, and reduced HMBW to 0.25°. The signal is located in the suitable range of measurement system, and our new device has not only a larger dynamic measurable range (1.33~1.48), but also higher resolution (8.13x10-6). In our experiment, we measured the angular shift of SPR and the reflective intensity change at a fixed angle. The resolution of the device is 8.13x10-6RIU. The multilayer structure was also used to simulate the position of nano-particle in micro-fluid channel. In order to minimize our detection system, we used the grating structure composed of 2D honeycomb array to couple surface plasmon wave and found at at proper incident wavelength of 833nm and angle of 50° has good SPR signal.

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Tasi, Shin-kai, and 蔡欣凱. "Wavelength-modulated circular heterodyne interferometry for SPR detection." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/41413719979870332014.

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碩士
國立中央大學
光機電工程研究所
98
A novel optical measurement technology“Wavelength-modulated circular heterodyne interferometry for SPR detection”is proposed. This study combined with heterodyne interferometry of high precision, real time measurement, and surface plasma resonance of high sensitivity and high resolution. This study uses direct modulation of a diode laser wavelength to produce heterodyne light source to reduce the costs, and proposes the concept of differential phase detection, which effectively remove the environmental impact on the system. Thus, this study can reach high-sensitivity and high resolution system effectiveness, to meet the needs of biomedical testing. According to the results, the sensitivity of the system is 1.21 × 104 (°/RIU) and the long time stability of differential phase is 0.048 degree, so the resolution of refractive index is up to 4 × 10-6 (RIU). This resolution is sufficient to detect the interface of biochemical reactions.

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Lee, Kuo-Hoong, and 李國宏. "Microfluidic systems for SPR sensing using microarray immunoassay." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/08040366249125116195.

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碩士
國立成功大學
工程科學系碩博士班
94
This study reports a novel microfluidic chip integrated with arrayed immunoassay for SPR (Surface plasmon resonance) phase imaging of specific bio-samples. The SPR imaging system uses a surface-sensitive optical technique to detect two-dimensional spatial phase variation caused by antibodies absorbed on a sensing surface composed of highly-specific proteins films. The developed system has a high resolution and a high-throughput screening capability and has been successfully applied to the analysis of multiple bio-molecules without the need for additional labeling in the long-term measurement. The microfluidic chip was fabricated by using MEMS (micro-electro-mechanical-systems) technology on glass and PDMS (Polydimethylsiloxane) substrates to facilitate well-controlled and reproducible analyte delivery. A micro flow sensor was fabricated to measure the pumping rate generated by the micropumps. In addition, since SPR detection is very sensitive to temperature variation, a micromachine-based temperature control module comprised of micro-heaters and a temperature sensor was used to maintain a uniform temperature with a variation less than 0.1°C during measurement. Besides, the SAM (self-assembled monolayers) technique was used to pattern the surface chemistry of the gold to adsorb rabbit IgG and its antibody to the modified substrates. The microfluidic chip is capable of transporting a specific amount of IgG solution inside multiple microchannels using micropumps/valves to the arrayed detection areas that are locally deposited so that highly-sensitive, highly-specific bio-sensing can be achieved. The developed microfluidic chips employed in SPR imaging experiments for immune detection could successfully detect the interaction of rabbit IgG and its antibodies. Various rabbit IgG concentrations and antibody interactions have been measured using the developed method. The integrated system was also tested for nonspecific interactions. Experimental data showed that no significant binding was found. The microfluidic chips were developed to have the potential to be widely used for bio-sensing applications. The development of microfluidic devices integrated with the SPR detecting system has several advantages, including being labeling-free, having a high sensitivity, and being capable of quantitatively analyzing nano-scale bio-molecules in real-time format. The developed system could be promising for various applications including medical diagnostics and biomedical research.

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Su, Chien Wei. "Enhanced Absorption by SPR for Solar Cell Application." 2007. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1308200715265000.

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Chang, Susanna, and 張端芳. "Array Format SPR Sensing Chip for Biomolecular Detection." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/72135069754763282453.

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碩士
國立臺灣大學
醫學工程學研究所
90
Surface Plasmon Resonance (SPR) has been used in biosensing techniques for decades. SPR sensors characterize the interaction of biomolecules by surface plasma wave (SPW), which interrogates biomolecules near the solid surfaces. SPR sensors can also detect the presence of biomolecules adsorption on a chemically modified surface by probing changes in the local refraction of index that occurs upon adsorption. In this thesis, principles of SPR theoretical backgrounds are briefly summarized. A robust MEMS-based fabrication process is introduced for SPR chip manufacture. The adsorption of albumin on chip surface will also be discussed in addition. SPR chip is integrated with an angular scanning SPR optical system. Different from conventional SPR bare gold chip, an array format SPR chip design is for multisensing site purpose. The array format SPR chip can be a real-time and parallel detection platform for various bio-molecules detection in one single optical system. SPR optical system in this thesis is rearranged and become a practical and manageable for experimental operation in this research.

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Dissertations / Theses on the topic 'SPR'

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