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Vukusic, Peter. "Sensing thin layers using surface plasmon resonance." Thesis, University of Exeter, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358142.
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Guo, Jing. "MULTI-MODE SELF-REFERENCING SURFACE PLASMON RESONANCE SENSORS." UKnowledge, 2013. http://uknowledge.uky.edu/ece_etds/13.
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Surface-plasmon-resonance (SPR) sensors are widely used in biological, chemical, medical, and environmental sensing. This dissertation describes the design and development of dual-mode, self-referencing SPR sensors supporting two surface-plasmon modes (long- and short-range) which can differentiate surface binding interactions from bulk index changes at a single sensing location. Dual-mode SPR sensors have been optimized for surface limit of detection (LOD). In a wavelength interrogated optical setup, both surface plasmons are simultaneously excited at the same location and incident angle but at different wavelengths. To improve the sensor performance, a new approach to dual-mode SPR sensing is presented that offers improved differentiation between surface and bulk effects. By using an angular interrogation, both surface plasmons are simultaneously excited at the same location and wavelength but at different angles. Angular interrogation offers at least a factor of 3.6 improvement in surface and bulk cross-sensitivity compared to wavelength-interrogated dual-mode SPR sensors.
Multi-mode SPR sensors supporting at least three surface-plasmon modes can differentiate a target surface effect from interfering surface effects and bulk index changes. This dissertation describes a tri-mode SPR sensor which supports three surface plasmon resonance modes at one single sensing position, where each mode is excited at a different wavelength. The tri-mode SPR sensor can successfully differentiate specific binding from the non-specific binding and bulk index changes.
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Nehru, Neha. "Reference Compensation for Localized Surface-Plasmon Resonance Sensors." UKnowledge, 2014. http://uknowledge.uky.edu/ece_etds/41.
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Noble metal nanoparticles supporting localized surface plasmon resonances (LSPR) have been extensively investigated for label free detection of various biological and chemical interactions. When compared to other optical sensing techniques, LSPR sensors offer label-free detection of biomolecular interactions in localized sensing volume solutions. However, these sensors also suffer from a major disadvantage – LSPR sensors remain highly susceptible to interference because they respond to both solution refractive index change and non-specific binding as well as specific binding of the target analyte. These interactions can severely compromise the measurement of the target analyte in a complex unknown media and hence limit the applicability and impact of the sensor. In spite of the extensive amount of work done in this field, there has been a clear absence of efforts to make LSPR sensors immune to interfering effects. The work presented in this document investigates, both experimentally and numerically, dual- and tri-mode LSPR sensors that utilize the multiple surface plasmon modes of gold nanostructures to distinguish target analyte from interfering bulk and non-specific binding effects. Finally, a series of biosensing experiments are performed to examine various regeneration assays for LSPR sensors built on indium tin oxide coated glass substrate.
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Badjatya, Vaibhav. "TUNABLE LASER INTERROGATION OF SURFACE PLASMON RESONANCE SENSORS." UKnowledge, 2009. http://uknowledge.uky.edu/gradschool_theses/588.
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Surface plasmons are bound TM polarized electromagnetic waves that propagate along the interface of two materials with real dielectric constants of opposite signs. Surface plasmon resonance (SPR) sensors make use of the surface plasmon waves to detect refractive index changes occurring near this interface. For sensing purposes, this interface typically consists of a metal layer, usually gold or silver, and a liquid dielectric. SPR sensors usually measure the shift in resonance wavelength or resonance angle due to index changes adjacent to the metal layer. However this restricts the limit of detection (LOD), as the regions of low slope (intensity vs. wavelength or angle) in the SPR curve contain little information about the resonance. This work presents the technique of tunable laser interrogation of SPR sensors. A semiconductor laser with a typical lasing wavelength of 650nm was used. A 45nm gold layer sputtered on a BK7 glass substrate served as the sensor. The laser wavelength is tuned to always operate in the region of highest slope by using a custom-designed LabVIEW program. It is shown that the sensitivity is maximized and LOD is minimized by operating around the region of high slope on the SPR curve.
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Johnston, Kyle S. "Planar substrate surface plasmon resonance probe with multivariant calibration /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/6069.
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Jorgenson, Ralph Corleissen. "Surface plasmon resonance based bulk optic and fiber optic sensors /." Thesis, Connect to this title online; UW restricted, 1993. http://hdl.handle.net/1773/5996.
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Matcheswala, Akil Mannan. "GOLD NANOSPHERES AND GOLD NANORODS AS LOCALIZED SURFACE PLASMON RESONANCE SENSORS." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_theses/60.
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A novel localized surface plasmon resonance (LSPR) sensor that differentiates between background refractive index changes and surface-binding of a target analyte (e.g. a target molecule, protein, or bacterium) is presented. Standard, single channel LSPR sensors cannot differentiate these two effects as their design allows only one mode to be coupled. This novel technique uses two surface plasmon modes to simultaneously measure surface binding and solution refractive index changes. This increases the sensitivity of the sensor.
Different channels or modes can be created in sensors with the introduction of gold nanospheres or gold nanorods that act as receptor mechanisms. Once immobilization was achieved on gold nanospheres, the technique was optimized to achieve the same immobilization for gold nanorods to get the expected dual mode spectrum. Intricate fabrication methods are illustrated with using chemically terminated self assembled monolayers. Then the fabrication process advances from chemically silanized nanoparticles, on to specific and systematic patterns generated with the use of Electron Beam Lithography.
Comparisons are made within the different methods used, and guidelines are set to create possible room for improvement. Some methods implemented failed, but there was a lot to learn from these unsuccessful outcomes. Finally, the applications of the dual mode sensor are introduced, and current venues where the sensors can be used in chemical and biological settings are discussed.
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Keathley, Phillip Donald. "DESIGN AND ANALYSIS OF NANO-GAP ENHANCED SURFACE PLASMON RESONANCE SENSORS." UKnowledge, 2009. http://uknowledge.uky.edu/gradschool_theses/643.
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Surface plasmon resonance (SPR) sensors are advantageous to other techniques of sensing chemical binding, offering quantitative, real-time, label-free results. Previous work has demonstrated the effectiveness of using dual-mode SPR sensors to differentiate between surface and background effects, making the sensors more robust to dynamic environments. This work demonstrates a technique that improves upon a previously optimized planar film dual-mode SPR sensor’s LOD by introducing a periodic array of subwavelength nano-gaps throughout the plasmon supporting material. First, general figures of merit for a sensor having an arbitrary number of modes are studied. Next, the mode effective index dispersion and magnetic field profiles of the two strongly bound modes found using a gap width of 20nm are analyzed. Qualitative analysis of the results demonstrates how such a design can enable better LODs in terms of each figure of merit. By optimizing a nano-gap enhanced sensor containing 20nm gaps, it is quantitatively demonstrated that the resulting modes improve upon almost every figure of merit, especially with respect to the orthogonality and magnitude of the sensitivity vectors, resulting in LODs approximately a factor of five less than the optimal planar design.
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Sommers, Daniel R. "Design and verification of a surface plasmon resonance biosensor." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/6967.
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The Microelectronics Group has been researching sensors useful for detecting and quantifying events in biological molecular chemistry, for example, binding events. Our previous research has been based primarily on quartz resonators. This thesis describes the results of our initial research of Surface Plasmon Resonance (SPR) based technology. This study contains the design and implementation of a fully functional SPR biosensor with detailed disclosure of monolayer construction, digital hardware interfaces and software algorithms for process the SPR sensors output.
An antibody monolayer was constructed on the biosensor surface with the goal of setting the strengths, weaknesses and limitation of measuring molecular events with SPR technology. We documented several characteristics of molecular chemistry that directly effect any measurements made using Surface Plasmon Resonance technology including pH, free ions, viscosity and temperature. Furthermore, the component used in our study introduced additional limitations due to wide variations amongst parts, the constraint of a liquid medium and the large surface area used for molecular interrogation. We have identified viable applications for this sensor by either eliminating or compensating for the factors that affect the measured results.
This research has been published at the inaugural IEEE sensors conference and to our knowledge is the first time a biosensor has been constructed by attaching a sensor to a PDA and performing all signal processing, waveform analysis and display in the PDAs core processor.
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Watkins, William L. "Study and development of localised surface plasmon resonance based sensors using anisotropic spectroscopy." Electronic Thesis or Diss., Sorbonne université, 2018. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2018SORUS505.pdf.
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La résonance de plasmon de surface localisée (LSPR) est définie comme l’oscillation collective du nuage d’électrons de conduction induite par un champ électrique externe. Dans le cas de nanoparticules composé de métaux nobles tels que l’or, l’argent, ou le cuivre,la résonance est localisée dans le visible ou le proche UV. La polarisabilité d’une nanoparticule est directement proportionnelle à quatre paramètres clefs : son volume, sa composition, sa forme et son milieu environnant. Ce sont ces propriétés qui font que la LSPR peut être utilisée à des fin de capteur. Dans le cas d’une particule isotrope, tel que la sphère, le spectre LSPR montre un seul pic d’absorption. Dans le cas d’une particule anisotrope, tel qu’une ellipsoïde, le spectre d’absorption a deux maxima distincts. Si on calcule la section efficace d’absorption en considérant une lumière non polarisée, on obtient deux maxima. Le point clef de ce type de système est la possibilité de découpler les deux résonances en utilisant une lumière polarisée. Dans cette description le système anisotrope est considéré comme microscopique, c’est à dire qu’il ne s’agit que d’une ou deux particules. Dans le cas d’un échantillon macroscopique, tel qu’une solution colloïdale d’ellipsoïdes ou nanotiges, le spectre d’absorption aura toujours deux maxima d’absorption, mais ceux-ci ne pourront pas être découplés car l’échantillon n’est pas globalement anisotrope. En revanche, si l’échantillon présente une anisotropie globale telle que des nanotiges alignés, ou des nanosphères organisées en ligne, il est possible d’avoir un spectre de plasmon dépendant de la polarisation de la lumière. Être capable de découpler les résonances d’un échantillon anisotrope permet de mesurer un spectre différentiel en prenant la différence des deux spectres d’absorption. Cela est expérimentalement possible en utilisant la spectroscopie de transmis- sion anisotrope qui permet la mesure de l’anisotropie optique. L’avantage est d’obtenir un spectre relative et différentiel donc plus stable et reproductible. De plus il est maintenant possible de suivre l’évolution de la réponse optique des particules plasmoniques, non plus en mesurant un déplacement spectral, mais en mesurant le changement d’intensité du signal à une longueur d’onde fixe. Cette méthode est utilisée pour deux cas d’études qui sont la mesure de l’interaction du dihydrogène avec des nanoparticules d’or, ainsi que la détection de faible pression partielle de dihydrogène dans un gaz porteur (argon, et air) à l’aide de palladium, pour des applications de capteur d’hydrogèneLocalised surface plasmon resonance (LSPR) is defined as the collective oscillation of the conduction electron cloud induced by an external electric field. In the case of nanoparticles composed of noble metals such as gold, silver, or copper, the resonance is located in the visible or near UV range. The polarisability of a nanoparticle is directly proportional to four key parameters: its volume, its composition, its shape and its surrounding environment. It is these properties that make LSPR useful for sensor applications. In the case of isotropic particles, such as spheres, the LSPR spectrum shows only one absorption peak. In the case of an anisotropic particle, such as an ellipsoid, the absorption spectrum has two or more distinct peaks. If the absorption cross-section is measured with unpolarised light, multiple maxima are obtained. The key point for these type of systems is the possibility to decouple the resonances using polarised light. In this description the anisotropic system is considered microscopic, i.e. it is only made of one or two particles. In the case of a macroscopic sample, such as a colloidal solution of ellipsoids or nanorods, the absorption spectrum will always have multiple absorption maxima, and they cannot be decoupled because the sample is not globally anisotropic.On the other hand, if the sample has a global anisotropy such as aligned nanorods, or nanosphere organised in lines, it is possible to have a plasmon spectrum dependent on the light polarisation. Being able to decouple the resonances of an anisotropic sample makes it possible to measure a differential spectrum by taking the difference of the two absorption spectra. This is experimentally possible by using anisotropic transmission spectroscopy which measures the optical anisotropy. The advantage is to obtain a relative and differential spectrum more stable and reproducible. Moreover, it is now possible to follow the evolution of the optical response of the plasmonic particles no longer by measuring a spectral shift but by measuring the change in intensity of the signal at a fixed wavelength. This method is used on two case studies which are the measurement of the interaction of dihydrogen with gold nanoparticles, as well as the detection of low partial pressure of dihydrogen in a carrier gas (argon, and air) using palladium nanoparticles, for hydrogen sensing applications
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Earp, Ronald Lee Jr. "Multiwavelength Surface Plasmon Resonance Sensor Designs for Chemical and Biochemical Detection." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30581.
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Surface plasmon resonance (SPR) sensors using multiwavelength light coupling are investigated to probe changes in refractive index that occur as a result of chemical or biochemical processes. Traditional SPR sensors have used angle modulation to facilitate detection at the sensor surface; however, the multiwavelength approach is novel and brings new functionality to SPR sensors.
The multiwavelength sensors are constructed on both fiber optic and bulk waveguides such as prisms. A thin metal film is deposited on the waveguide surface to support the surface plasmon (SP) mode. The evanescent field produced by light propagating through the waveguide can be coupled into the surface plasmon mode thus attenuating the transmitted light. This coupling is dependent upon phase matching between the light wavevector and the surface plasmon wavevector. The wavevectors are directly related to the wavelength of light, thickness of analyte on the sensor surface and the refractive index of the analyte. As these parameters change, the light output from the sensor will be affected. Other thin films can be subsequently deposited on the metal to functionalize the sensor surface for a particular analyte of interest. A theoretical background and details of the sensor construction is given.
The developed sensors are tested in a variety of application systems. Experimental results for refractive index sensing in bulk liquid applications is shown. Observed sensitivity approaches that of conventional SPR techniques. Alkyl-thiol monolayer systems are studied to investigate kinetics of formation and the thickness resolution of the sensor. A biochemical system is investigated to compare the sensors with other immunoassay techniques. Ionic self-assembled monolayer (ISAM) systems are investigated to probe structure and determine their usefulness as an immobilization layer for biochemical species.
A mathematical model based on Fresnel reflection equations is developed to predict sensor response. This model can be used to selectively vary sensor parameters to optimize the response for a specific analyte system or to calculate system parameters based on experimental results. Results from the various experiments are compared with the model.
Experimental results and interpretations are discussed along with future work and potential improvements. Classical SPR sensors are also discussed along with comparisons with the multiwavelength sensors. Future improvements to SPR sensors design are considered, as is the application of the technology to high-throughput drug screening for pharmaceuticals.Ph. D.
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Bathae, Kumaresh Prasanth. "OPTIMIZATION OF A DUAL-MODE SURFACE PLASMON RESONANCE SENSOR." UKnowledge, 2007. http://uknowledge.uky.edu/gradschool_theses/424.
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Surface plasmon waves are TM polarized charge density waves that propagate at the interface of two media with real dielectric constants of opposite sign (i.e. liquid dielectric and certain metals). Surface plasmon resonance (SPR) sensors use these waves to detect refractive index changes adjacent to the metal layer. Refractive index changes arise from the binding of an analyte (e.g. a target molecule, protein, or bacterium) to the functionalized metal layer or from interfering effects such as changes in solution index. Standard, single channel SPR sensors cannot differentiate these two effects as their design allows only one mode to be coupled. This novel self-referencing technique employs two surface plasmon modes to simultaneously measure surface binding and solution refractive index. Dual surface plasmon modes are achieved by matching the refractive indices on either side of the metal film. The two modes generated - symmetric, long-range surface plasmon (LRSP) and anti-symmetric, short-range surface plasmon (SRSP) - have different field profiles and hence assist in differentiating solution refractive index changes from surface layer formation. Amorphous Teflon, with a refractive index close to water, is chosen as the buffer layer and gold is chosen as the metal layer. Magnesium fluoride, with a higher index than Teflon, is used as the buffer layer when using ethanol as the base solution. The sensor operation was optimized through simulations to yield higher sensitivity, lower reflectivity and resonances within the spectrometers range. Optimization results showed good performance over a wide range for Teflon, MgF2 and gold thicknesses which helped in the fabrication of the sensor. Demonstration of self-referencing operation was done through two different sets of experiments: (1) formation of an alkanethiol self-assembled monolayer on gold in the presence of ethanol and methanol solutions having different refractive indices and (2) streptavidin-biotin binding with solutions of different NaCl concentration and thus different refractive indices. In both these experiments, the resonance wavelengths were accurately predicted, reflectivity varied by 10-15% and sensitivity by 25% from that of the simulated values.
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Kumaresh, Prasanth Bathae. "Optimization of a dual-mode surface plasmon resonance sensor." Lexington, Ky. : [University of Kentucky Libraries], 2007. http://lib.uky.edu/ETD/ukyelen2007t00566/PrasanthBathaeKumaresh_MSThesis.pdf.
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Thesis (M.S.)--University of Kentucky, 2007.Title from document title page (viewed on June 11, 2007). Document formatted into pages; contains: xviii, 123 p. : ill. (some col.). Includes abstract and vita. Includes bibliographical references (p. 119-122).
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Chang, Sehoon. "Organic/inorganic hybrid nanostructures for chemical plasmonic sensors." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39545.
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The work presented in this dissertation suggests novel design of chemical plasmonic sensors which have been developed based on Localized Surface Plasmon Resonance (LSPR), and Surface-enhanced Raman scattering (SERS) phenomena. The goal of the study is to understand the SERS phenomena for 3D hybrid (organic/inorganic) templates and to design of the templates for trace-level detection of selected chemical analytes relevant to liquid explosives and hazardous chemicals. The key design criteria for the development of the SERS templates are utilizing selective polymeric nanocoatings within cylindrical nanopores for promoting selective adsorption of chemical analyte molecules, maximizing specific surface area, and optimizing concentration of hot spots with efficient light interaction inside nanochannels. The organic/inorganic hybrid templates are optimized through a comprehensive understanding of the LSPR properties of the gold nanoparticles, gold nanorods, interaction of light with highly porous alumina template, and the choice of physical and chemical attributes of the selective coating.
Furthermore, novel method to assemble silver nanoparticles in 3D as the active SERS-active substrate has been demonstrated by uniform, in situ growth of silver nanoparticles from electroless deposited silver seeds excluding any adhesive polymer layer on template. This approach can be the optimal for SERS sensing applications because it is not necessary to separate the Raman bands of the polyelectrolyte binding layer from those of the desired analyte. The fabrication method is an efficient, simple and fast way to assemble nanoparticles into 3D nanostructures.
Addressable Raman markers from silver nanowire crossbars with silver nanoparticles are also introduced and studied. Assembly of silver nanowire crossbar structure is achieved by simple, double-step capillary transfer lithography. The on/off SERS properties can be observed on silver nanowire crossbars with silver nanoparticles depending on the exact location and orientation of decorated silver nanoparticles nearby silver nanowire crossbars.
As an alternative approach for the template-assisted nanostructure design, porous alumina membrane (PAM) can be utilized as a sacrificial template for the fabrication of the nanotube structure. The study seeks to investigate the design aspects of polymeric/inorganic hybrid nanotube structures with plasmonic properties, which can be dynamically tuned by external stimuli such as pH.
This research suggests several different organic/inorganic nanostructure assemblies by various template-assisted techniques. The polymeric/inorganic hybrid nanostructures including SERS property, pH responsive characteristics, and large surface area will enable us to understand and design the novel chemical plasmonic sensors.
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Para, Prashanthi. "FABRICATION OF NANOSTRUCTURES FOR IMPROVED PERFORMANCE OF ELECTROCHEMICAL SENSORS AND FOR REFERENCE COMPENSATION IN LOCALIZED SURFACE PLASMON RESONANCE SENSORS." UKnowledge, 2009. http://uknowledge.uky.edu/gradschool_theses/130.
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L‐glutamate is associated with several neurological disorders; thus, monitoring fast dynamics of L‐glutamate is of great importance in the field of neuroscience. Electrode miniaturization demanded by many applications leads to reduced surface area and decreased amounts of immobilized enzymes on coated electrodes. As a result, lower signal‐to‐noise ratios are observed for oxidase‐enzyme based sensors. To increase the signal‐to‐noise ratio we have developed a process to fabricate micro‐ and nano‐ structures on the microelectrode surface.
Localized surface‐plasmon resonances (SPR) has been extensively used to design label‐free biosensors that can monitor receptor‐ligand interactions. A major challenge with localized SPR sensors is that they remain highly susceptible to interference because they respond to both solution refractive index changes and surface binding of the target analyte. The key concept introduced in the present work is the exploitation of transverse and longitudinal resonance modes of nanorod arrays to differentiate between bulk refractive index changes and surface interactions. The transverse bulk sensitivity of the localized SPR sensor (107 nm/RIU) remains competitive with typical single mode gold nanosphere SPR sensors. The figure of merit for the device’s cross‐sensitivity (1.99) is comparable to that of typical wavelength‐interrogated propagating SPR sensors with self referencing.
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Bender, William John Havercamp. "A chemical sensor based on surface plasmon resonance on surface modified optical fibers." Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/40097.
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A sensor is described which utilizes the phenomenon of surface plasmon resonance to detect changes in refractive index of chemical or biochemical samples applied to a surface modified optical fiber.
The sensor is constructed by polishing a short section of the lateral surface of an optical fiber to its evanescent field surrounding the fiber core. One or more thin films are applied to the polished section of the fiber to produce the sensing element. One of the films is the metal silver, which acts as the support for the surface plasmon.
Under the proper conditions, TM polarized energy propagating in the fiber can be coupled to a surface plasmon electromagnetic mode on the metal film. This coupling depends on the wavelength, the nature of the fiber, the refractive index and thickness of the thin films applied to the fiber, and the refractive index of a chemical sample in contact with the modified surface. The fiber to plasmon coupling is seen as a large attenuation of the light reaching the distal terminus of the fiber.Ph. D.
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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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Reaver, Nathan George Frederick. "Development and Characterization of Aptamers for the use in Surface Plasmon Resonance Sensors for the Detection of Glycated Blood Proteins." University of Toledo / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1373319138.
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Khalid, Muhammad. "A highly integrated surface plasmon resonance sensor based on a focusing diffractive optic element." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18444.
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Surface plasmon resonance (SPR) sensing is now widely used in biosensing applications. There is significant scope to reduce the cost and complexity of existing commercial devices by increasing the level of optical integration. This thesis presents an SPR sensor that utilizes a diffractive optical element (DOE) which is integrated directly into the sensor-head and which significantly reduces the optical complexity. This design is intended for eventual mass replication via a suitable molding technique. This system is designed to be used within an angular sensing scheme and the DOE delivers the required 15º angular beam divergence. The beam-steering optics are modeled using ray-tracing, while the diffraction efficiency analysis of the DOE is performed using both scalar and rigorous techniques. The complete design, fabrication and experimental results are presented.La détection par résonance plasmonique de surface est fréquemment employée dans les biocapteurs. Il serait donc avantageux de réduire le coût et la complexité des appareils commerciaux en augmentant leur niveau d'intégration optique. Cette thèse présente un capteur par résonance plasmonique de surface qui utilise un élément d'optique diffractive intégré directement dans la tête du capteur pour simplifier le système optique. Le capteur est conçu pour être éventuellement fabriqué à grande échelle par moulage. Le système est basé sur la détection angulaire et l'élément diffractif permet d'obtenir les 15 degrés de divergence nécessaire. L'optique utilisée pour contrôler le faisceau lumineux est modelée par lancer de rayon alors que l'analyse de l'élément diffractif est accomplie à l'aide de méthodes scalaires et vectorielles. La conception et la fabrication du système sont présentées, ainsi que des résultats de tests expérimentaux.
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Howe, Carmel Leah. "Developing a novel sensor technology for detecting neural activity based on surface plasmon resonance." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/52244/.
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One of the main goals of contemporary systems neuroscience is to understand how sensory inputs are processed, networks are formed and the resulting functional outputs. To achieve this, a recording technique is required that can detect action potentials with single-cell resolution for a long period of time across a large network. Current imaging techniques available are limited in at least one of the four elements needed to fulfill this aim (a) the technique needs to be able to detect every action potential (b) from every neuron (c) for a long period of time (d) from an entire network. Neural activity has been shown to produce fast intrinsic optical signals that are the result of refractive index changes causing light scattering and birefringence associated with membrane depolarisation. To date no one has successfully managed to exploit these intrinsic optical signals in a practical robust recording system. Surface plasmon resonance (SPR) is a technique that can detect extremely small changes in refractive index and is capable of detecting this membrane localised refractive index change with a high spatio-temporal resolution. This thesis describes the design and development of an imaging system based on surface plasmon resonance to detect the refractive index change of a cell membrane during neural activity. This thesis, first theoretically examines the different processes that occur during neural activity that could affect the resulting SPR response. The change in refractive index and therefore, light intensity was calculated considering the reorientation of dipoles and ion flux during an action potential. The planar gold surfaces required to produce surface plasmon resonances were characterised and the imaging system was shown to be sensitive enough to detect these small refractive index changes. There were no visible light intensity changes after recording the optical response from one action potential. This led to the development of the experimental protocol and a data analysis tool was developed to align and average over a number of action potentials to reduce the noise floor as much as possible and increase the signal-to-noise ratio. Unfortunately, it was determined to a high degree of certainty that no action potentials were detected by the planar gold SPR sensors. It was hypothesised the SPR signal from these cell membrane localised refractive index changes was averaged across the relatively large surface area of the planar gold sensor which was why no response was detected. A novel sensor design was investigated by reducing the gold sensor size to that of one cell to improve coupling or isolation of the plasmons to a single cell. SPR at planar metal/dielectric interfaces and localised SPR for metal nanoparticles have both been extensively studied, but it is less clear what happens to the optical properties at the micrometer scale. Gold patterns of different sizes in the micrometer range were therefore, produced using photolithography. Typical SPR responses were observed for all gold microstructures, however, as expected they were not as sensitive and were wider than that of the planar gold controls. This phenomenon became more pronounced as the length of the gold structure decreases, as expected because of the spatial constriction of the propagating surface plasmon. Although the sensitivity of the micron-sized gold surfaces was less than that of the planar gold surface, with the latter unable to detect these refractive index changes. The process still suggested that the SPR technique could be successfully implemented to detect individual action potentials. Reducing the sensor size to that of one cell could improve coupling and stop the signal being averaged across the sensor. Unfortunately, it was determined to a high degree of certainty that no action potentials were detected by the gold microstructure SPR sensors.
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Torrance, David. "Influence of the Local Dielectric Environment and its Spatial Symmetry on Metal Nanoparticle Surface Plasmon Resonances." Honors in the Major Thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1195.
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This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.Bachelors
Sciences
Physics
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Kitenge, Denis. "Optical detection of CO and H2 based on surface plasmon resonance with Ag-YSZ, Au and Ag-Cu nanoparticle films." Scholar Commons, 2009. http://scholarcommons.usf.edu/etd/2047.
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Silver, gold, and copper metallic nanoparticle films have been utilized in various MEMS devices due to not only their electrical but also their optical properties. The focus of this research is to study the detection at room temperature of carbon monoxide (CO) and hydrogen (H2) via Surface Plasmon Resonance (SPR) phenomenon of silver-embedded Yttrium Stabilized Zirconium (Ag-YSZ) nanocomposite film, gold (Au) nanoparticle film, and an alloy film of silver-copper (Ag-Cu) , grown by the Pulsed Laser Deposition (PLD). To determine the appropriate film materials for quick and accurate CO and H2 detection at room temperature with the PLD technique, the growth process was done repeatedly. Optical tools such as X-Ray Diffraction, Alpha Step 200 Profilometer, Atomic Force Microscopy, and Scanning Electron Microscopy were used to characterize thin films.
The gas sensing performance was studied by monitoring the SPR band peak behavior via UV/vis spectrophotometer when the films were exposed to CO and H2 and estimating the percent change in wavelength. The metallic nanoparticle films were tested for concentration of CO (100 to 1000 ppm) and H2 (1 to 10%). Silver based sensors were tested for the cross-selectivity of the gases. Overall the sensors have a detection limit of 100 ppm for CO and show a noticeable signal for H2 in the concentration range as low as 1%. The metallic films show stable sensing over a one-hour period at room temperature. The SPR change by UV/vis spectrophotometer shows a significant shift of 623 nm wavelength between 100 ppm CO gas and dry air at room temperature for the alloy films of Ag-Cu with a wider curve as compared to silver and gold films upon their exposure to CO and H2 indicating an improvement in accuracy and quick response.
The results indicate that in research of CO and H2 detection at room temperature, optical gas sensors rather than metal oxide sensors are believed to be effective due to not only the absence of chemical involvement in the process but also the sensitivity improvement and accuracy, much needed characteristics of sensors when dealing with such hazardous gases.
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Palframan, Mark C. "Real Time Biological Threat Agent Detection with a Surface Plasmon Resonance Equipped Unmanned Aerial Vehicle." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23241.
Full textAbstract:
A system was developed to perform real-time biological threat agent (BTA) detectionwith a small autonomous unmanned aerial vehicle (UAV). Biological sensors just recently
reached a level of miniaturization and sensitivity that made UAV integration a feasible task.
A Surface Plasmon Resonance (SPR) biosensor was integrated for the first time into a small
UAV platform, allowing the UAV platform to collect and then quantify the concentration
of an aerosolized biological agent in real-time. A sensor operator ran the SPR unit through
a groundstation laptop and was able to wirelessly view detection results in real time. An
aerial sampling mechanism was also developed for use with the SPR sensor. The collection
system utilized a custom impinger setup to collect and concentrate aerosolized particles.
The particles were then relocated and pressurized for use with the SPR sensor. The sampling
system was tested by flying the UAV through a ground based plume of water soluble
dye. During a second flight test utilizing the onboard SPR sensor, a sucrose solution was
autonomously aerosolized, collected, and then detected by the combined sampling and SPR
sensor subsystems, validating the system\'s functionality. The real-time BTA detection system
has paved the way for future work quantifying biological agents in the atmosphere and
performing source localization procedures.
Master of Science
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Damos, Flavio Santos. "Aplicação da ressonancia de plasmon de superficie e da microbalança de cristal de quartzo na investigação de processos interfaciais visando o desenvolvimento de sensores." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/248396.
Full textAbstract:
Orientador: Lauro Tatsuo KubotaTese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: O presente trabalho descreve as aplicações da ressonância de plásmon de superfície (surface plasmon resonance-SPR) e da microbalança de cristal de quartzo (quartz crystal microbalance-QCM) na investigação de processos interfaciais, visando o melhor entendimento e aplicação dos sistemas investigados bem como o estabelecimento das aplicações da técnica SPR aliada à eletroquímica. Neste sentido são apresentadas investigações do comportamento óptico-eletroquímico da molécula de azul de metileno (sistema 1), polímeros condutores (sistema 2) e monocamadas auto-organizadas (sistema 3). A escolha de tais sistemas, embora distintos, tem a finalidade de exploração ampla da técnica SPR na investigação de processos superficiais e interfaciais. O uso da técnica SPR na investigação do sistema 1 mostra a sua aplicabilidade no monitoramento do intumescimento de filmes em dimensões nanométricas e a investigação de processos adsortivos e difusionais com elevada sensibilidade. Assim sendo, a técnica SPR foi aplicada na investigação de processos de formação de filmes finos de polímeros condutores, bem como os processos de dopagem destes filmes. Neste sentido, foi investigada a eletropolimerização do pirrol e da polianilina bem como o efeito de dopantes aniônicos sobre as propriedades ópticas e eletroquímicas destes materiais. As medidas ópticas obtidas foram correlacionadas aos processos de dopagem e desdopagem dos filmes confeccionados mediante um estudo comparativo destes processos por QCM tendo em vista a consolidação da mesma na investigação de tais processos. Por fim, com o propósito de explorar a sensibilidade da técnica SPR a sistemas de dimensões sub-nanométricas, foram investigadas monocamadas auto-organizadas de ácido 11-mercapto-undecanóico e mono(6-deoxi-6-mercapto)-b-ciclodextrina. Neste sentido, foram determinadas a espessura e a constante dielétrica destes filmes, assim como a cinética de adsorção destes empregando um modelo de adsorção fundamentado na adsorção, desorção e re-arranjo molecular
Abstract: The present work describes the applications of surface plasmon resonance (SPR) and quartz crystal microbalance (QCM) in the investigation of interface processes in the attempt to improve the understanding and application of the investigated systems as well as the establishment of the applications of the SPR allied with electrochemical techniques. In this sense, are presented the investigation of the electrochemical behavior of the methylene blue molecule (system 1), conducting polymers (system 2) and self-assembled monolayers (system 3). The selection of these systems, although distinct, has a focus on the exploration of the SPR technique in the investigation of surface and interface processes. The use of SPR technique in the investigation of the system 1 shows its applicability in the monitoring of swelling of films in nanometric size as well as the investigation of adsorptive and diffusional processes with high sensitivity. Thus, SPR was applied in the investigation of construction of thin conducting polymer films as well as its doping processes. In this sense, were investigated pyrrole and aniline electropolymerization as well as the effects of anionic dopants on its optical and electrochemical properties. The optical measurements were correlated with the doping and dedoping processes of the films by means of a comparative study of these processes by QCM due to the better establishment of this technique in the investigation of these processes. Finally, with the purpose of explore the sensitivity of the SPR technique in sub-nanometric size systems, the SPR technique was applied in the investigation of selfassembled monolayers of 11-mercapto-undecanoic acid and mono(6-deoxy-6-mercapto)-b- cyclodextrin. In this sense, were determined the thickness and dielectric constant of these films as well as the adsorption kinetic by using a kinetic model based on adsorption, desorption and re-arrangement of molecules
Doutorado
Físico-Química
Mestre em Química
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Schreiber, Benjamin, Dimitra Gkogkou, Lina Dedelaite, Jochen Kerbusch, René Hübner, Evgeniya Sheremet, Dietrich R. T. Zahn, Arunas Ramanavicius, Stefan Facskoa, and Raul D. Rodriguez. "Large-scale self-organized gold nanostructures with bidirectional plasmon resonances for SERS." Technische Universität Chemnitz, 2018. https://monarch.qucosa.de/id/qucosa%3A23477.
Full textAbstract:
Efficient substrates for surface-enhanced Raman spectroscopy (SERS) are under constant development, since time-consuming and costly fabrication routines are often an issue for high-throughput spectroscopy applications. In this research, we use a two-step fabrication method to produce self-organized parallel-oriented plasmonic gold nanostructures. The fabrication routine is ready for wafer-scale production involving only low-energy ion beam irradiation and metal deposition. The optical spectroscopy features of the resulting structures show a successful bidirectional plasmonic response. The localized surface plasmon resonances (LSPRs) of each direction are independent from each other and can be tuned by the fabrication parameters. This ability to tune the LSPR characteristics allows the development of optimized plasmonic nanostructures to match different laser excitations and optical transitions for any arbitrary analyte. Moreover, in this study, we probe the polarization and wavelength dependence of such bidirectional plasmonic nanostructures by a complementary spectroscopic ellipsometry and Raman spectroscopy analysis. We observe a significant signal amplification by the SERS substrates and determine enhancement factors of over a thousand times. We also perform finite element method-based calculations of the electromagnetic enhancement for the SERS signal provided by the plasmonic nanostructures. The calculations are based on realistic models constructed using the same particle sizes and shapes experimentally determined by scanning electron microscopy. The spatial distribution of electric field enhancement shows some dispersion in the LSPR, which is a direct consequence of the semi-random distribution of hotspots. The signal enhancement is highly efficient, making our SERS substrates attractive candidates for high-throughput chemical sensing applications in which directionality, chemical stability, and large-scale fabrication are essential requirements.
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Schuster, Tobias. "Entwurf und experimentelle Untersuchung eines faseroptischen Oberflächenplasmonenresonanz-Sensors." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-203235.
Full textAbstract:
In der medizinischen Diagnostik, Bioverfahrenstechnik und Umwelttechnik besteht ein steigender Bedarf an kompakten Analysegeräten für die schnelle Vor-Ort-Detektion spezifischer biochemischer Substanzen. Im Rahmen der Arbeit wurde daher ein neuartiger faseroptischer Sensor entwickelt, der in der Lage ist kleinste Brechzahländerungen, z.B. durch molekulare Bindungsprozesse, zu detektieren. Die hohe Empfindlichkeit an der vergoldeten Spitze der Sensorfaser beruht auf der Oberflächenplasmonenresonanz (SPR) einer einzelnen Mantelmode, die durch ein langperiodisches Fasergitter (LPG) ermöglicht wird. Die Übertragungsfunktion des Sensors wurde unter Verwendung eines Schichtwellenleitermodells schnell und präzise modelliert. Es konnte gezeigt werden, dass in einem wässrigen Umgebungsmedium die höchste Empfindlichkeit im Spektralbereich um 660 nm unter Annahme einer rund 35~nm dicken und 2~mm langen Goldbeschichtung erreicht wird. Weiterhin wurde nachgewiesen, dass mit einer intermediale Schicht aus Cadmiumsulfid die SPR der Mantelmode in einen höheren Spektralbereich verschoben und damit die Empfindlichkeit deutlich verbessert werden kann. Um eine geringe Polarisationsabhängigkeit des Sensors sicherzustellen, wurde ein nasschemisches Abscheidungsverfahren für die allseitige Goldbeschichtung der Sensorfaser entwickelt. Die spezifischen optischen Eigenschaften dieser Abscheidungen wurden mit Hilfe von LPGs untersucht, die durch eine spezielle UV-Belichtung hergestellt wurden. Die Experimente ergaben, dass die komplexe Permittivität nasschemischer Abscheidungen mit Schichtdicken oberhalb von 50~nm mit aufgedampften Goldschichten vergleichbar ist. Die Verluste der adressierten Mantelmoden wurden mit einer äquivalenten Sensoranordnung aus zwei identischen LPG untersucht. Dabei konnte ein Skalierfaktor abgeleitet werden, der die effiziente Berechnung der Mantelmodendämpfung erlaubt. Es wurde nachgewiesen, dass die Brechzahlauflösung etablierter volumenoptischer SPR-Sensoren mit einer einfachen Transmissionsmessung an einer geeigneten Wellenlänge erreicht werden kann. Die äußerst kompakte Sensorfläche des faseroptischen Sensors ermöglicht darüber hinaus die Untersuchung deutlich kleinerer Probenvolumina ohne ein zusätzliches mikrofluidisches System zu benötigen. Es wurde gezeigt, dass sekundäre Brechzahländerungen aufgrund von Temperaturschwankungen oder unspezifische Ablagerungen durch eine differentielle Auswertung zweier identischer Sensoren kompensiert werden können. Die verbleibende Querempfindlichkeit wird durch die Polarisationsabhängigkeit der Sensoren bestimmt. Die geringste Querempfindlichkeit konnte daher mit einer homogenen nasschemischen abgeschiedenen Sensorfläche nachgewiesen werdenCompact analysis devices which facilitate the rapid detection of specific biochemical substances are in increasing demand in the fields of point-of-care medical diagnostics, bioprocess engineering and environmental engineering. The aim of this work was therefore to design a novel fiber-optic sensor able to detect small refractive index changes such as those caused by molecular binding processes. The high level of sensitivity at the gold-plated tip of the sensor fiber stems from the surface plasmon resonance (SPR) of a single cladding mode, which is the result of a long-period fiber grating (LPG). The transfer function of the sensor was calculated quickly and accurately using a slab waveguide model. It was observed that the highest level of sensitivity in an aqueous ambient medium is achieved at a wavelength of 660 nm assuming a gold coating of 35 nm in thickness and 2 mm in length. Furthermore, it was demonstrated that an intermedial cadmium sulfide layer shifts the SPR of the cladding mode towards higher wavelengths, thus leading to significantly enhanced sensitivity. An electroless plating process for the omnidirectional deposition of gold on the sensor fiber was developed in order to minimize the sensor\'s dependency on polarization. The specific optical properties of the gold layer deposited were investigated with the aid of LPGs fabricated using a special UV exposure method. The experiments showed the complex permittivity of electroless platings with a thickness of over 50 nm to be comparable with that of evaporated gold layers. The losses of the addressed cladding modes were investigated using an equivalent sensor setup consisting of two identical LPGs. This facilitated the determination of a scaling factor enabling the effcient calculation of cladding mode attenuation. It was demonstrated that it is possible to obtain the refractive index resolution of established volume optical SPR sensors with the aid of simple transmission measurements at a specific wavelength. Moreover, the extremely compact sensing area of the fiber-optic sensor enables the investigation of smaller sample volumes without the need for an additional microfluidic system. Secondary refractive index changes caused by temperature fluctuations or unspecific binding events can be compensated for by means of the differential interrogation of two identical fiber-optic sensors. The residual cross sensitivity is determined by the polarisation dependency of the sensor. The lowest cross sensitivity was therefore demonstrated in combination with a homogeneous electroless plated sensor surface
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Zheng, Rui. "The Development of an Aptamer-based Surface Plasmon Resonance (SPR) Sensor for the Real-time Detection of Glycated Protein." University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1352917255.
Full text
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Read, Thomas. "Antibody screening using a biophotonic array sensor for immune system response profile." Thesis, University of Exeter, 2013. http://hdl.handle.net/10871/14742.
Full textAbstract:
With a population both increasing in number and age, comes a need for new diagnostic tools in the healthcare system, capable of diagnosing and monitoring multiple disorders in a cheap and effective way to provide personalised healthcare. Multiplex label-free biosensors have the potential to rejuvenate the current system. This thesis details the assessment of an ‘in house’ built labelfree array screening technology that has potential to be a point-of-care diagnostic for personalised medicine – the Array Reader. The performance of the Array Reader platform is considered in detail and optimised for both antibody and protein screening arrays. A Global Fit protocol is developed to extract kinetic constants for all protein-protein interactions, assuming a Langmuir adsorption binding model. Standard operating procedures are developed to provide optimised dynamic range, sensitivity, reproducibility and limit of detection of immuno-kinetic assay. A new antibody bio-stack signal amplification strategy is formed, improving the detection limit 60-fold. As a consequence, the bio-stack resulted in a novel method for determining the plasmon field penetration depth, defining the assay sensing volume at the nanoparticle surface. Antibody screening arrays were investigated with an IgG quantification assay to determine total IgG content from serum samples. It relied on the ability of protein A/G to bind antibodies via the Fc region. Specific antigens were used to measure the binding properties of the antibody Fab region. By characterising both regions, we have gained insight into the overall ability of an antibody to trigger an immune response. Protein screening assay were investigated targeting C-reactive protein (CRP), a marker of inflammation. The assays performance characteristics compared favourably with clinically used CRP assays. Finally, an antibody screening array was developed to assess the efficacy of a vaccine against Yersinia pestis in a non-human primate model. The vaccine screening array is an excellent example of the versatility of the platform and just one of many possible applications for the future.
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"Phase detection techniques for surface plasmon resonance sensors." Thesis, 2011. http://library.cuhk.edu.hk/record=b6075189.
Full textAbstract:
In addition, this project also investigated schemes that might enhance the phase change in the SPR sensor. The "double-pass" and "multi-pass" approaches through which the SPR phase can be amplified upon hitting the sensor surface more than once, have been experimentally studied and successfully demonstrated. A double-pass method can immediately offer two times of phase change as compared to the singlepass one. Accordingly the multi-pass scheme offers a higher then two times phase enhancement. Such improvement in phase detection is extremely important for biosensing applications involving small molecules, small proteins, DNA and etc. Another approach for detection performance improvement is to incorporate a multilayer configuration for the biosensing surface. In order to improve the dynamic measurement response, we proposed to use a multiple resonant angle measurement approach in conjunction with the single-beam self-referenced phase-sensitive SPR configuration. With the use of many multiple incident angles, the system provided sensing capability that covers a refractive index (RI) 1.33 to over 1.38. A 128-element array detector was employed to measure the resonance phase change over the range of the incident angles to ensure a reasonably continuous phase response curves achievable from the system.This project is concerned with the development and optimization of optical sensors based on measuring the phase change of surface plasmon resonance (SPR) effect. The phase sensitive SPR technique provides very high sensitivity performance due to the fact that an abrupt phase jump occurs near the resonance dip, thus resulting in large phase shift with very small change in the sensing medium. A range of different measurement techniques for enhancing system sensitivity have been investigated. Moreover we also studied the phase change characteristics around the SPR dip region by means of simulation in order to explore various approaches for achieving further improvement in sensitivity and as well as wide dynamic range. Since SPR is caused by electron charge density oscillations in metal surface in which the wave momentum required for plasmon wave excitation is always larger than that for free space, an inverted prism-coupling scheme (prism-metal-dielectric) is commonly used and this configuration was also employed in our experimental setup, particularly for the SPR biosensor based on differential phase Mach-Zehnder interferometer configuration. This design primarily operates by taking advantage of the fact that SPR only affects the p-polarization while leaving the s-polarization unchanged. This means that differential phase measurement between the p- and s- polarizations will result in SPR signals that are completely free from any disturbances that are common to both channels. Experimental results obtained from glycerin/water mixtures indicate that the sensitivity limit of our scheme is 5.48 x 10 -8 refractive index unit per 0.01° phase change. To our knowledge, this is a significant improvement over previously obtained results when gold is used as the sensor surface. While acknowledging that accurate optical alignment is a crucial requirement for the Mach-Zehnder interferometer and it is often not easy to maintain high degree alignment accuracies in practical situations, we have developed a versatile and low cost single-beam self-referenced phase-sensitive surface SPR sensing system. The system exhibits a root-mean-square phase fluctuation of +/-0.0028° over a period of 45 minutes, i.e. a resolution of +/-5.2x10 -9 refractive index units. The enhanced performance has been achieved through the incorporation of three design elements: (i) a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected; (ii) a differential measurement scheme to eliminate spurious signals not related to the sensor response; (iii) elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulator. Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional florescence-based techniques.
Wu, Shu Yuen.
Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: .
Thesis (Ph.D.)--Chinese University of Hong Kong, 2011.
Includes bibliographical references (leaves 132-147).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract also in Chinese.
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Chiu, Wei-I., and 邱瑋懿. "Surface Modification on Nanoparticles for Enhancing Localized Surface Plasmon Resonance Sensors." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/42057801542750620527.
Full textAbstract:
碩士國立臺灣師範大學
化學系
103
In this research, we developed three kind of LSPR(Localized surface plasmon resonance) sensor by modify nano Au or coating others compounds. First of all, we use MPTMS modify Carbon nanotube that it can adsorb on nano Au. Repeat absorb carbon nanotube and nano Au Staggered. We got mutilayer gold/carbon nanotube LSPR sensor. It not only improve the sensitivity of VOCs also reduce the pieces of sensor.Second, we use ionic solution coating on nano particles.Ionic solution has low volatility, low inflammability,and stable at many physical properties. We take adventage of ionic solution can catch more VOCs that sensor can responses bigger signal. Finally, we use absorbent polymer mix salts to developed humidity sensor. Different kinds of salts has varied absorbing properties. We mix several kinds of salts in polymer make a humidity sensor wide sensing range.
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Guan, You-Lun, and 官有倫. "Investigation of Surface Plasmon Resonance Sensors based on Prism Couplers." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/98328315102711554862.
Full textAbstract:
碩士國立清華大學
材料科學工程學系
95
Surface plasmon resonance (SPR) is a physical phenomenon which occurs in an interface between metal and dielectric materials. A biosensor based on SPR can provide various excellent characteristics such as high sensitivity, rapid examination, label-free pretreatment, and real-time monitor. Thus, an SPR biosensor is often utilized for biodetection and immunochemistry. In this thesis, first we simulated SPR results of two kinds of adhesion layers, titanium and chromium, and measure their experimental SPR results. Both simulations and observations confirm that the SPR curves with titanium display narrower FWHM and lower reflectivity than those with chromium because of smaller internal damping within titanium. Next, we discuss the influence of thicknesses of gold film on SPR. The simulated SPR results of various thicknesses of gold film by Matlab are compared with their experimental data. Our experimental results indicate that a gold layer of 47 nm thick presents the best coupling efficiency to exhibit the deepest reflectance minimum, which is in a good agreement with our numerical simulation. Furthermore, we also observe that the angle shift of the reflectance minimum is highly sensitive to different analytes attached on the surface of the gold film but independent with its thickness. Furthermore, we utilize the aforementioned innovative properties of the SPR biosensor to investigate the binding condition of biomolucules. A couple of high affinity biomolecules, biotin and streptavidin, are adopted to examine the functions of the home-made SPR biosensor. First, the pretreatment of self-assembly is used to immobilize the biotin on the gold film of SPR substrate, and the characteristic absorption peaks of FT-IR of the biotin indicate that indeed the biotin anchors on the gold film. Afterwards, the measurements of various concentrations of streptavidin by home-made SPR system display its high sensitivity; even the 10-8 M of streptavidin can be detected. In addition, we increase the injection rate of streptavidin solution but there is not a significant change because the determining step of kinetic theory is the binding between the biotin and the streptavidin. Currently we are further developing and improving the performance of our SPR biosensors including reduction of cost, miniaturization for portable SPR sensors, and enhancement of the sensitivity for the next generation of SPR systems.
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Li, Chung-Hsun, and 李忠勳. "Design and Fabrication of Lithium Niobate Surface Plasmon Resonance Sensors." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/87596665232887881617.
Full textAbstract:
碩士國立臺灣大學
光電工程學研究所
94
Lithium niobate (LiNbO3) based surface plasmon resonance (SPR) sensor is demonstrated in this paper. LiNbO3 possesses the birefringence and the good electro-optical (EO) effect. We use the birefringence to fabricate the waveguide where only TM-polarized wave can be guided on +Z-cut LiNbO3 with the proton-exchanged method. Then the thin film of gold and titanium dioxide (TiO2) are sequentially deposited on the surface of the waveguide. Gold is used to excite surface plasma wave (SPW) and the oxide layer can adjust the operated range of refractive index of analyte to 1.33 ~ 1.4. With 60nm-thick gold, 35 and 40nm-thick TiO2, SPR is successfully excited on LiNbO3 and the sensitivities are respectively determined to be 436.84nm/RIU and 501.32nm/RIU with wavelength interrogation, which agree well with the theoretical simulation. This waveguide-based SPR sensor requires no extra polarization controller. Thus the size of the SPR sensor system can be reduced further. In addition, LiNbO3 has good EO effect, which can be utilized to change the phase shift caused by SPR, and the highly sensitive sensor can be achieved by phase interrogation in previous papers. Therefore, the highly sensitive sensor system with the EO effect possessed by LiNbO3 has a great potential on fabrication cost and the size of the sensor system. We discuss the phase shift with the modeling and finish the design of the Mach-Zehnder based SPR sensor. The calculated sensitivity is as high as 9.62848 10-8 RIU.
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Chu, Yi-Shin, and 朱怡欣. "Design and Fabrication of Waveguide-based Surface Plasmon Resonance Sensors." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/53689902456068334659.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
93
This is to study the influences of analyte refractive index, metal film thickness, and interaction length on the behavior of waveguide-based surface plasmon resonance (SPR) sensors. To understand the basic characteristics of the device, multilayer structure with complex indices is simulated based on transfer matrix method and complex mode tracking technique. Moreover, SPR sensors using Ge-doped SiO2 optical waveguide on Si substrate, and Au as the sensing film are successfully implemented by semiconductor fabrication process. The sensitivity and SPR-induced attenuation as high as 5532.33 nm/RIU and 14.80 dB, respectively, are observed. The experimental results exhibit the same trend as predicted by the simulation.
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Huang, Chiao-Pang, and 黃喬邦. "Study of Optimal Design in Surface Plasmon Resonance Based Sensors." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/21909257480833838209.
Full textAbstract:
碩士國立臺灣大學
光電工程學研究所
97
In this thesis, we introduce the history of Surface plasmon resonance, and its development in recent years. Focusing on theoretical derivation and electromagnetic wave field analysis of the surface plasmon based sensor to obtain the principle for figuring out the effect of each parameters. Including thickness, refractive index, and corresponding incident angle of each layer. Furthermore, analysis about the TM polarized electromagnetic wave distribution between dielectric material and metal by using waveguide theory and couple mode theory. Based on above approaching to analyze the structure adding dielectric nano-layer with high refractive index on conventional Krestchmann’s geometry. We obtain much better sensitivity results than convention one and the principle might be applied in other application. Here the simulation software we use the software including RSoft, COMSOL and MathCAD to repeat the research done by former then compare with the design of this paper. Finally, we conclude the optimal design principle that most sensitive in change of refractive index respect to incident angle under different thickness layers and materials.
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Pao, Ming-Chi, and 包明麒. "Surface plasmon resonance sensors based on a new heterodyne interferometry." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/57211197537379113662.
Full textAbstract:
碩士國立清華大學
原子科學系
91
The investigation of surface plasmon resonance by several measurement systems based on the measurement of intensity or the measurement of phase are described in this dissertation. The measurement systems consist of (1) an optical intensity-based system, (2) an intensity-based interferometric system, (3) a heterodyne interferometric system, and (4) a novel common-path heterodyne interferometric system. The former two are based on the measurement of intensity while the others are based one the measurement of phase. Among them, the novel common-path heterodyne interferometric system, which is built with a pair of quarter waveplates to improve the measurement sensitivity, is my original design. The surface plasmon resonance for each measurement system is theoretical and experiment verified. The results from each system are used to make a comparism. In effect, the most sensitive one is my original design, the novel common-path heterodyne interferomatic system. The measurement resolution of refractive index for this system is theoretically estimated to be 4×10-9RIU(refractive index unit). An experiment result of 3.4×10-6RIU has been achieved by this study. Furthermore, a protein-protein interaction experiment is also included. So far, the detection limit for protein of 0.3μg/ml has been obtained. Both the measurement resolution and the detection limit for protein have a great space to improve in the near future.
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Fan, Wan Ting, and 范菀庭. "Fabrication and characterization of surface plasmon resonance sensors incorporated with metal/dielectric/metal surface plasmon structures." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/71287521979993452453.
Full textAbstract:
碩士長庚大學
光電工程研究所
102
he enhancement of sensitivity and precision of surface plasmon resonance (SPR) sensors by metal/dielectric/metal (MDM) structures was investigated in this work. Based on numerical simulation, both the MDM SPR sensors with appropriate parameters and the traditional SPR sensors were fabricated. The full width at half maximum of the MDM SPR sensor under angular interrogation was found to be narrower than that of traditional SPR sensor both in numerical simulation and in practice. In addition, a novel MDM SPR sensor featured with the function of self-correction was developed. The principle of this device was based on the facts that an odd-symmetric surface plasmon wave (SPWodd) and an even-symmetric SPW (SPWeven) can be sustained by the MDM structure and another SPW (SPWAu/solution) can be sustained by the bottom metal/analyst interface. As the bottom metal is thin enough, SPWodd and SPWAu/solution can couple with each other and then split into two SPW modes, SPWodd-like and SPWAu/solution-like with the intended characteristics. The resonance angle of SPWAu/solution-like can be pushed to approach the critical angle by this coupling effect and the sensitivity associated with this resonance is therefore improved. Besides, the SPWodd-like is barely affected by the refractive index variation of the solution. This fact indicates that the SPWodd-like signal can be adopted as a reference for canceling the common mode noises during the measurement. Details of the realization are included in this thesis.
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Mai, Li-wei, and 麥立偉. "Sensitivity-tunable Surface Plasmon Resonance Sensor." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/42124698638113378346.
Full textAbstract:
碩士國立中央大學
光機電工程研究所
100
A novel optical measurement technology “Sensitivity-tunable surface plasmon resonance sensor” is proposed. This system has advantage of high sensitivity and high resolution by employing heterodyne interferometry for SPR phase detection. Besides, the sensitivity is tunable according to difference of samples by adjusting the azimuthal angle of quarter wave plate. This technique is quite a potential sensing system with two-dimension. In this study, the pure water and alcohol solutions are used to estimate sensitivities and resolutions. Increasing the azimuthal angle makes a better sensitivity while sample’s refractive index is higher. In additional, to tune the quarter wave plate can provide a larger dynamic range as the difference of refractive index larger. According to the results, the best sensitivity of this system is 1.7×10^5 (°/RIU). The resolution is 5.3×10^-7 RIU with the stability of phase drift 0.09 degree. Meanwhile, the sensing area is 2mm×2mm.
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Liu, Hsiang-Yu, and 劉祥瑜. "STUDY OF SENSITIVITY AND RESONANCE RESPONSE FOR THREE-LAYER STRUCTURE SURFACE PLASMON RESONANCE FIBER SENSORS." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/54yg9a.
Full textAbstract:
碩士大同大學
光電工程研究所
102
In this Thesis, we proposed a new three-layer structure Surface Plasmon Resonance (SPR) fiber sensors, adding an extra nano Au thin film on the Indium Tin Oxide (ITO) film surface of a bilayer Au/ITO SPR fiber sensor, to investigate the sensing sensitivity and the influence of the surface plasmon resonance. We introduced an ITO thin film as the dielectric layer on the Au film surface of an original SPR fiber sensor and deposited an extra nano Au film layer on the ITO surface by sputtering method. The sensing sensitivity and the strength of resonance of the SPR fiber sensors have been study by changing the thickness of the superficial nano Au film. A series of different refractive indices of oil are dropped on the nano Au surface of the three-layer SPR fiber sensor to analyze the center wavelength of the SPR dip curve in respect to the changes of the surface nano Au film thickness. The thickness of the nano Au film enable us to alter the center wavelength of the SPR dip curve and to increase the sensing sensitivity. But the increasing of superficial nano Au film thickness also leads to the degradation of the surface plasmon resonance. The experimental results show that the superficial Au film with 2.11 nm thickness of the Au/ITO/Au Three-layer SPR fiber sensor possesses optimum SPR sensing outcomes, such as better sensing sensitivity than that of original bilayer SPR fiber sensor.
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Lin, Min-Ping, and 林旻平. "Chemical Sensor Based on Surface Plasmon Resonance." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/66667296742937328926.
Full textAbstract:
碩士國立臺灣大學
高分子科學與工程學研究所
100
Numerous food safety incidents take place in recent years. For example, the 2008 Chinese milk scandal of which adulterated melamine was found in infant milk powder. Additionally, plasticizer (such as, bis(2-ethylhexyl) phthalate(DEHP), Benzyl butyl phthalate(BBP), dibutyl phthalate(DBP)) was used to replace palm oil in foods and drinks as a clouding agent in 2011, Taiwan. Therefore, to quickly and accurately characterize food or ingredients is extremely important for preventing damage from toxic substances. To approach this goal, there is a novel methodology of rapid detection by adopting surface-enhanced Raman scattering (SERS) effect on highly sensitive substrate. It will be powerful in detecting drugs and chemicals. In this study, we develop a simple and low cost solution process to fabricate a novel Ag coated monodispersive silica colloid monolayer substrate to enhance Raman scattering signals of organic dyes, plasticizer and ketamine. By tuning the process parameters, a significant enhancement of Raman scattering by surface plasmon was observed. We also found that there is a relationship between the absorption wavelength of chemicals and the Raman excitation wavelength. The enhancement factor of Raman signal would be higher since the overlapped wavelength. The enhancement factor of organic dyes on our SERS substrate is 40,000 times. For the plasticizers, the enhancement factor of plasticizers on our SERS substrate is 21,000 times. A simple extraction method was used to remove the interference efficiently, leading to the lowest detecting limits 40 ppm and 20 ppm of plasticizer and ketamine respectively. Consequently, the developed SERS method with high sensitivity, low cost and quick detection in this study will be beneficial for the design and fabrication of functional devices and sensors.
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Lin, Yen-Yu, and 林延諭. "Sensor Sensitivity Investigation for Surface Plasmon Resonance." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/72629701155473000966.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
101
Surface plasmon resonance is a physical phenomenon that happens between the interface of metal and dielectric materials. By applying this feature onto the biosensing applications, the real-time high sensitivity and label-free detection are possessed. Therefore, it has been extensively utilized in bio-detection and immunochemistry for its efficiency in analyzing the refraction index of detected materials. In this research, through actual operations and simulations, the actions and influences from different detected materials will be investigated for two different kinds of surface plasmon resonance sensors, hybrid plasmonic waveguide and prism coupling sensors. For the hybrid plasmonic waveguide, the optimal sensitivity of sub-micrometer single-mode siliconwire under the optical fiber communication wavelength band was designed through the FDTD numerical simulation software analysis. The process technology of hybrid plasmonic waveguides adopted the standard 0.35-μm I-line stepper semiconductor lithography in HsinChu National Nano Device Laboratories. The 0.35-μm wide Al-Si-Cu alloy was successfully placed through three-layer photomasks on top of the sub-micrometer siliconwire that is 0.4 μm in width using the exposure energy manipulation and precise alignment between layers. Under the prism coupling for sensor operations, Matlab commercial software was applied for numerical simulation and analysis. The simulation results showed that with a wavelength of 1550 nm, the lowest reflectance and favorable coupling efficiency were achieved at 30-nm thick gold film. Additionally, the resonance angle will deviate from the covered materials. The experimental results demonstrated that when the angular modulation was used as our detection method, the sensor sensitivity for resonance angles could reach 131.32 deg/RIU among a refraction index of 1.3119~1.326749. And when the DI water was taken as the detected material, its resolution could achieve 1.4306 deg-1. The sensor sensitivity for glucose concentration would reach 1786.4 dB/RIU when the incident angle reaches 61.9° with a wavelength of 1550 nm. This sensor sensitivity level could identify between 100 mg/dL to 1000 mg/dL of glucose concentration which could successfully detect changes in glucose concentration. Hence, this could be utilized to efficiently monitor the small variation amount in glucose concentration. Moreover, the 1 μg/ml and 10 μg/ml concentrations of Mycobacterium tuberculosis DNA that MacKay Hospital provided were also successfully detected in the wavelength domain through the prism coupling surface plasmon resonance. From the report, the commercial bioequipment, NanoDrop 2000c from Thermo Fisher Scientific, for Mycobacterium tuberculosis DNA could achieve 0.4 μg/ml, which is close to the half of our tested data, 1 μg/ml. In conclusions, the wavelength modulated surface plasmon resonance owns the potential for future sample-saving microfluidics technologies.
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張添棋. "Effects of Bending the Optical Fibers on Surface Plasmon Resonance Fiber-Optic Sensors." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/p54kc9.
Full textAbstract:
碩士國立嘉義大學
電子物理學系光電暨固態電子研究所
106
Optical fiber sensors have a number of advantages such as small size and reusability and can be used for the real-time measurement of dynamic changes without requiring any labeling. Currently, such sensors are widely applied in biosensing. This study uses multimode optical fibers with core diameters of 1000 and 365 μm to develop surface plasmon resonance fiber-optic sensors. First, diamond grinding sheets with different particle sizes were used to polish the sides of the multimode optical fibers until the thickness of the fibers was equal to half of their diameter. Next, a thin gold film was vapor deposited on the polished surface to fabricate a surface plasmon resonance fiber-optic sensor, whereas gold nanoparticles were deposited on the polished surface by a chemical surface modification method to fabricate a localized surface plasmon resonance-based fiber-optic sensor. A halogen lamp was used as a light source that directly coupled the light into the multimode optical fibers by a focusing an objective lens. Finally, an optical spectrometer was used to detect changes in the surface plasmon resonance associated with the transmitted light spectrum using the two sensors under different degrees of bending of optical fibers in a sucrose aqueous solution with different refractive indices. Results show that the light intensity at the center of resonance, wavelength, and sensitivity of the fiber-optic sensors with 365 and 1000 μm core diameters changed with the degree of bending of the optical fibers. The sensitivity of the surface plasmon resonance fiber-optic sensor with a thin gold film and core diameter of 1000 μm significantly increased with the degree of bending of the optical fiber. On the other hand, the wavelength at the center of resonance of the localized surface plasmon resonance-based fiber-optic sensor with gold nanoparticles had a stable and linear relation with the change in the refractive index of the sucrose aqueous solution caused by the change in the degree of bending of the optical fiber. Keywords: Surface plasmon resonance; Localized surface plasmon resonance; Fiber-optic sensor; Multimode optical fibers; Vapor deposition; Gold film; Chemical surface modification method; Gold nanoparticle
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Wu, Yin-Cyuan, and 吳胤駩. "Study of Lactoferrin Sensors on the Localized Surface Plasmon Resonance of Gold Nanoparticles." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/19718690262127365571.
Full textAbstract:
碩士國立雲林科技大學
材料科技研究所
99
This research uses sodium citrate-tannin reduction method to fabricate 20nm glod nanoparticles, which bond on ITO glass substrates through self-assembly to form gold nanolayer. Anti-human lactoferrin is bonded on gold nanolayer and forms sensing layer by biomolecule immobilization. The theorem of sensing is to take the advantage of the localized surface plasmon resonance(LSPR) that gold particles possess when in nano size. This characteristics enable gold nanoparticles to construct a high-sensitive, high-definition and real-time detective lactoferrin sensor. This research aims to explore how the different fabricating conditions of gold nanoparticles self-assembled monolayer and multilayer can affect the covered rate and uniformed rate. Also, the performance of gold nanoparticle LSPR sensor when detecting lactoferin is under disscussion. The results indicate that under the condition of using sodium citrate aqueous solution as reducing agent, 100 units of 0.01% HAuCl4 solution and 1 unit of 1% sodium citrate aqueous solution can fabricate stable distributed 20 nm gold nanoparticles. During the process of gold nanoparticle self-assembling layer, using GPTS solution, which blends GPTS, DI water and ethanol, to modify function group, and bonding gold nanoparticles for 8 hours afterward, better covered rate and uniformed rate gold nanoparticle monolayer is produced. Continuely using GPTS solution to modify the monolayer substract enable fabricating bi-layer with better roughness and higher gold nanoparticles covered rate. The gold nanoparticle LSPR sensor has good specificity to lactoferrin solution. The method-detection limit is 0.5 µg/ml, linear detective range is between 0.5µg/ml to 2µg/ml, and the responding time is 10 minutes. This sensor has effective performance to unknown-concentration lactoferrin in human breast milk.
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Wu, Tien-Ming, and 吳添銘. "Study of Sensors based on the Localized Surface Plasmon Resonance of Gold Nanoparticles." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/80317788264388033170.
Full textAbstract:
碩士國立雲林科技大學
電子與資訊工程研究所
95
The theorem of this research applies the localized surface plasmon resonance of gold nanoparticles. The absorbance spectrum varied with different refraction indices and dielectric constants of the environment.Fabricated LSPR biosensors have a high sensitivity, high resolvability and being capable of quantitatively analyzing nano-scale bio-molecules in real-time and labeling-free. We use 5nm gold nanoparticles to make self-assembled monolayer(SAM) and multilayers nano-thinfilms on MPTMS modified glass substrates. Then those films were used to detect silver ion, to analyze the immunoassay of antigen and antibody by UV-VIS spectrophotometers, and to test sucrose solution with different refractive indices.The results show that the signal will vary linearly under different refractive index and the different gold nanoparticle layers affect the linearity. The gold nanoparticles, modified by the organic functional group, show execellent selectivity, and effectively binding with silver ions. Besides, the absorbance and peak wavelength of these self-assembled films show obvious red-shifted. For detecting silver ion solutions, the detection limit can reach to 0.5×10-3 M. The sensitivity results of immunoassay for Mouse antigen, antibody and BSA can attain down to 0.5ng/ml. Self-assembled nano-thinfilms, either monolayer or multilayers, show promising results for LSPR biosensors.
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Lo, Ya-Ling. "Optical Enhanced Nanoparticle-Based Surface Plasmon Resonance Sensor." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1107200417441400.
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Alqarni, Sondos. "Terahertz Surface Plasmon Resonance Sensor for Material Sensing." Thesis, 2014. http://hdl.handle.net/10012/8355.
Full textAbstract:
Terahertz wave (THz) is comprised of electromagnetic waves carrying frequencies from 0.1 to 30 THz. Terahertz radiation has the ability to interact with a wide range of materials, such as plastic and paper, and to provide low-‐energy probing of the system's electronic nature, including inter/intra-‐molecular motions and Debye relaxation -‐ these are not accessible by other wavelengths. Further appealing feature for THz ray is the nonionizing nature and the distinctive optical response of various materials are important for analyzing diverse applications such as material quality control, pharmaceutical, industrial production lines, and biological. Upon that THz waves have been utilized for imaging and spectroscopy, especially Terahertz Time-‐Domain Spectroscopy (THz-‐TDS) associated to its ability in measuring the change in the electric field with high sensitivity in time-‐domain.
Surface plasmon-‐polaritons (SPPs) at metal-‐dielectric interfaces have been proven for several decades as a reliable technique for surface analysis and investigation of thin films due to the two dimensional nature of SPPs and the strong electromagnetic field at the interface. Extraordinary transmission of light through subwavelength hole arrays has attracted many areas of applications including optical data storage, near field microscopy, optical displays, and thin film sensing. The enhancement in the tunneled transmission light stemming from the coupling with SPP by the surface configurations has been explored through the waveguide theory and the grating theory of the frequency-‐selective characteristic of SPP resonances.
At THz frequencies, the extraordinary transmission through thin metallic hole arrays has been demonstrated through the excitation of SPP on the metal–dielectric interface confining the incident THz pulse around the holes, hence precluding THz pulse from easily passing and attenuating into the conductor. Implementing THz SPP in thin film sensing has great potential for industrial applications because the two dimensional nature of SPPs and the strong electromagnetic field at the interfacewith the THz natural reaction with the material provides reliable measurements of thin film spectroscopy including optical and dielectric constants, film thickness, and inhomogeneities at interfaces with high precision. This motivates the investigation of the characteristics such as purity of thin organic film including PMMA and those used in organic light emitting diode (OLED) through THz SPR devices.
Two SPR devices contain either 2D periodic circular or square hole array in 500 nm Al on an 5 mm-‐thick intrinsic silicon, or a single subwavelength aperture surrounded by concentric periodic grooves of a set period in a metal plate (which is known as a Bull’s eye structure), and was fabricated by following the micro-‐ fabrications process encompassed from UV photolithography and wet and dry etching to transfer the pattern into the Al film. The SPR device consisting of 2D periodic circular or square hole array with and without thin Poly(methyl methacrylate) (PMMA) film on it is placed at the focus of the THz beam in transmission THz-‐TDS, where the spectrum is obtained from the Fourier-‐ transformed sample and reference THz pulses. The transmission is obtained from the ratio between the sample spectrum and reference spectrum, whereas the phase change is the phase difference between the two spectra. To avoid overlap with water absorption lines, the optimal SPR device design has a period of 320 μm and square holes of 150 μm side length. We successfully confirmed the theoretical SPR frequencies for metal-‐silicon mode and demonstrate a shift to 0.9211 THz due to 2 μm of PMMA layer on the surface.
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Li, Kuan-ting, and 李冠廷. "Surface Plasmon Resonance Sensor Based on Tilted Gratings." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/17467017292843528539.
Full textAbstract:
碩士逢甲大學
自動控制工程學系
104
In this study, an optical fiber-based microsensor is developed by designing tilted optical fiber grating measurement system based on surface plasmon resonance technology. The tilted fiber gratings were applied to excite the surface plasma wave and evanescent coupling with a surface plasmon resonance. In order to improve its sensing sensitivity, we have polished single side of optical fiber in the written tilted fiber gratings. The fabrication process is divided into three steps. First, by writing tilted fiber gratings in optical fiber, the light can enter into cladding. Second, by using side polishing fabrication in the written tilted fiber gratings, enhance the evanescent field can be enhanced obviously. Finally, by using a sputtering machine to deposit metal films on the surface of optical fibers, they are main media of surface plasma resonance. The sensors have been completed after above-mentioned fabrication. In this study, the incident light with 780 nm wavelength was used as the laser source because the wavelength approaches surface plasmon resonance wavelength. It have good sensing sensitivity and the space of tilted fiber gratings is 780 nm. Experimental results show that the sensitivity of brine and blanching water are 48.11 nm/RIU and 158.73 nm/RIU respectively.
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Lo, Ya-Ling, and 羅雅鈴. "Optical Enhanced Nanoparticle-Based Surface Plasmon Resonance Sensor." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/28932906663828751053.
Full textAbstract:
碩士國立臺灣大學
電機工程學研究所
92
Nanotechnology is the most attractive term in science literature. And the noble metal nanoparticles which has size- and shape-dependent properties has promoted a great deal of excitement during the last decades. These nanostructure materials have potential in many areas such as biological detection, drug delivery system, low threshold lasers, sensors and optical filters. In this thesis, we utilize the Kretschmann configuration surface plasmon resonance to investigate the optical properties of two types of nanoparticles, the rod- and sphere-shaped nanoparticles with four different sizes of nanosphere and four different absorption wavelengths of nanorods. The nanoparticles are deposited on the gold substrate with self-assembly technique. The ellipsometry method is utilized for the measurements of the optical constants of the nanosphere layer. Furthermore, the nanorods are employed for the testing of bio-sensitivity with ALV virus and IgG antibody. The nanosphere layer exhibits the size-dependent FWHM and reflectance of the surface plasmon resonance dip. The nanorods display a narrower SPR dip than the nanosphere. These are partly related to the nanoparticle behaviors of scattering spectra. The depositions of nanoparticle enhance the optical field in the vicinity of the particle and form a strong perturbation of the electromagnetic filed. Thus this phenomenon greatly influences the variation of the refractive index. We utilize the mechanism to amplify the SPR signal and can detect the concentration of antigen down to 6x10^-13 g/mL so far.
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"Surface Plasmon Resonance (SPR) Bio-Sensors to Detect Target Molecules in Undiluted Human Serum." Doctoral diss., 2015. http://hdl.handle.net/2286/R.I.35425.
Full textAbstract:
abstract: Biosensors aiming at detection of target analytes, such as proteins, microbes, virus, and toxins, are widely needed for various applications including detection of chemical and biological warfare (CBW) agents, biomedicine, environmental monitoring, and drug screening. Surface Plasmon Resonance (SPR), as a surface-sensitive analytical tool, can very sensitively respond to minute changes of refractive index occurring adjacent to a metal film, offering detection limits up to a few ppt (pg/mL). Through SPR, the process of protein adsorption may be monitored in real-time, and transduced into an SPR angle shift. This unique technique bypasses the time-consuming, labor-intensive labeling processes, such as radioisotope and fluorescence labeling. More importantly, the method avoids the modification of the biomarker’s characteristics and behaviors by labeling that often occurs in traditional biosensors. While many transducers, including SPR, offer high sensitivity, selectivity is determined by the bio-receptors. In traditional biosensors, the selectivity is provided by bio-receptors possessing highly specific binding affinity to capture target analytes, yet their use in biosensors are often limited by their relatively-weak binding affinity with analyte, non-specific adsorption, need for optimization conditions, low reproducibility, and difficulties integrating onto the surface of transducers. In order to circumvent the use of bio-receptors, the competitive adsorption of proteins, termed the Vroman effect, is utilized in this work. The Vroman effect was first reported by Vroman and Adams in 1969. The competitive adsorption targeted here occurs among different proteins competing to adsorb to a surface, when more than one type of protein is present. When lower-affinity proteins are adsorbed on the surface first, they can be displaced by higher-affinity proteins arriving at the surface at a later point in time. Moreover, only low-affinity proteins can be displaced by high-affinity proteins, typically possessing higher molecular weight, yet the reverse sequence does not occur. The SPR biosensor based on competitive adsorption is successfully demonstrated to detect fibrinogen and thyroglobulin (Tg) in undiluted human serum and copper ions in drinking water through the denatured albumin.Dissertation/Thesis
Doctoral Dissertation Electrical Engineering 2015
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Wu, Chien-Lin, and 吳建霖. "Fabrication and Characterization of Localized Surface Plasmon Resonance Sensors for Mid-Infrared Range Applications." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/rnms86.
Full textAbstract:
碩士國立臺灣大學
光電工程學研究所
107
Recently the fabrication of metallic nano-structures and subsequent applications to sensing based on localized surface plasmon resonance (LSPR) has drawn a lot of attentions. By nanotransfer printing (nTP) method, fabrication of quality SPR sensors was realized in our lab. However, the applications were limited in the visible range, so extension to mid-infrared is attractive. In this thesis, we study how to fabricate metallic nanodisks. Through a novel fabrication process, the periodic metallic nanodisks were made onto silicon chip and D shaped silicon core fiber. To simulate the optical characteristics of the LSPR sensors, a commercial software, FDTD Solutions was used in this study. The simulated results revealed the trends of the measured transmission spectra and the characteristics of LSPR were also confirmed and discussed. In refractive index sensing, various concentrations of glucose solution were under test, and the resonant wavelengths of the spectra shifted as the concentration changed. The fingerprint signal in mid infrared range was enhanced by LSPR.
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HUA, JIAN-TING, and 華健廷. "Implementation of Surface Plasmon Resonance Sensor System Using Guided-Mode Resonance Filter." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/86qw3r.
Full textAbstract:
碩士國立虎尾科技大學
光電工程系光電與材料科技碩士班
106
This paper mainly studies the application of surface plasmon resonance (SPR) and guided mode resonance (GMR) elements. The grating structure is fabricated using nanoimprinting and coated with titanium dioxide (Tio2) or gold (Au) film. We polarized the led flashlight as an experimental light source and incident on the SPR element. When turning the SPR angle and measuring with a spectrometer, it can be seen that the intensity of the reflected light at a specific wavelength is significantly decreased. If the refractive index of the medium on the SPR element is changed, the resonance wavelength will shift too. Then, the reflected light of the SPR element is incident on the guided mode resonance (GMR) element, and the angle of the guided mode resonant element is adjusted to resonate at our predicted wavelength. After changing the refractive index, if the SPR resonance wavelength coincides with the GMR resonance wavelength, it will decrease in the intensity measurement, so that the function of the concentration sensor can be achieved.