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Littérature scientifique sur le sujet « EIS-biosensor »

Auteur : Grafiati

Publié le 1 avril 2023

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Articles de revues sur le sujet "EIS-biosensor"

Oliveira, A. C., et L. H. Mascaro. « Evaluation of Acetylcholinesterase Biosensor Based on Carbon Nanotube Paste in the Determination of Chlorphenvinphos ». International Journal of Analytical Chemistry 2011 (2011) : 1–6. http://dx.doi.org/10.1155/2011/974216.

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An amperometric biosensor for chlorphenvinphos (organophosphorus pesticide) based on carbon nanotube paste and acetylcholinesterase enzyme (CNTs-AChE biosensor) is described herein. This CNTs-AChE biosensor was characterized by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The SEM result shows the presence of CNTs and small lumps, due to the enzyme AChE, which has a type of cauliflower formation. From EIS analysis is possible to observe increasedRtcfor CNTs-AChE biosensor when compared to the carbon nanotube paste electrode for the reaction [Fe(CN)6]4−/3−. Using a chronoamperometric procedure, a linear analytical curve was observed in the4.90×10-7–7.46×10-6 M range with limit of detection of1.15×10−7 M. The determination of chlorphenvinphos in the insecticide sample proved to be in agreement with the standard spectrophotometric method, with a 95% confidence level and with a relative error lower than 3%. In this way, the CNTs-AChE biosensor presented easy preparation, fast response, sensitivity, durability, good repeatability, and reproducibility.

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Manickam, Arun, Aaron Chevalier, Mark McDermott, Andrew D. Ellington et Arjang Hassibi. « A CMOS Electrochemical Impedance Spectroscopy (EIS) Biosensor Array ». IEEE Transactions on Biomedical Circuits and Systems 4, n^o 6 (décembre 2010) : 379–90. http://dx.doi.org/10.1109/tbcas.2010.2081669.

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Le, Hien T. Ngoc, et Sungbo Cho. « Sensitive Electrochemical Detection of Phosphorylated-Tau Threonine 231 in Human Serum Using Interdigitated Wave-Shaped Electrode ». Biomedicines 10, n^o 1 (22 décembre 2021) : 10. http://dx.doi.org/10.3390/biomedicines10010010.

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The development of an electrochemical biosensor for the detection of phosphorylated-tau threonine 231 (p-tau231), a biomarker of Alzheimer’s disease (AD), has yet to be achieved. Therefore, in this study, we developed a simple, small size, cheap, and sensitive electrochemical biosensor based on an interdigitated wave-shaped electrode via an activated self-assembled monolayer to preserve a specific anti–p-tau231 antibody (IWE/SAM/EDC-NHS/anti–p-tau231). Detection of p-tau231 in human serum (HS) using the biosensor was undertaken using electrochemical impedance spectroscopy (EIS). The change in charge-transfer resistance (Rct) in the EIS analysis of the biosensor indicated the detection of p-tau231 in HS within a wide linear range of detection (10−4–101 ng mL−1), and a low limit of detection (140 pg mL−1). This lower limit is less than the detection level of p-tau231 in cerebrospinal fluid (CSF) (700 pg mL−1) of AD patients and the level of CSF p-tau231 of patients with mild cognitive impairment (501 pg mL−1), demonstrating the possibility of using the biosensor in detection of p-tau231 at early stage AD. A high binding affinity and low dissociation constant (Kd) between anti–p-tau231 and p-tau231 in HS was demonstrated by using a biosensor and Kd was 7.6 pM, demonstrating the high specific detection of p-tau231 by the biosensor. The good selectivity of the biosensor for the detection of p-tau231 with differential analytes was also examined in this study.

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Gasparyan, L. F., I. A. Mazo, V. V. Simonyan et F. V. Gasparyan. « EIS Biosensor for Detection of Low Concentration DNA Molecules ». Journal of Contemporary Physics (Armenian Academy of Sciences) 55, n^o 1 (janvier 2020) : 101–9. http://dx.doi.org/10.3103/s1068337220010144.

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Zhou, Yaoyu, Lin Tang, Xia Xie, Guangming Zeng, Jiajia Wang, Yaocheng Deng, Guide Yang, Chen Zhang, Yi Zhang et Jun Chen. « Sensitive impedimetric biosensor based on duplex-like DNA scaffolds and ordered mesoporous carbon nitride for silver(i) ion detection ». Analyst 139, n^o 24 (2014) : 6529–35. http://dx.doi.org/10.1039/c4an01607f.

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Jamshaid, Talha, Ernandes Taveira Tenório-Neto, Abdoullatif Baraket, Noureddine Lebaz, Abdelhamid Elaissari, Ana Sanchís, J. Pablo Salvador et al. « Development of Novel Magneto-Biosensor for Sulfapyridine Detection ». Biosensors 10, n^o 4 (21 avril 2020) : 43. http://dx.doi.org/10.3390/bios10040043.

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In this work, we report the development of a highly sensitive biosensor for sulfapyridine detection based on an integrated bio micro-electromechanical system (Bio-MEMS) containing four gold working electrodes (WEs), a platinum counter electrode (CE), and a reference electrode (RE). Firstly, the cleaned WEs were modified with 4-aminophenylacetic acid (CMA). Then, (5-[4-(amino)phenylsulfonamide]-5-oxopentanoic acid (SA2BSA) was immobilized onto the transducers surface by carbodiimide chemistry. The analyte was quantified by competitive detection with SA2BSA immobilized on the WE toward a mixture of Ab155 antibody (with fixed concentration) and sulfapyridine. In order to obtain a highly sensitive biosensor, Ab155 was immobilized onto magnetic latex nanoparticles surface to create a 3D architecture (Ab-MLNp). Using electrochemical impedance spectroscopy (EIS), we investigated the influence of the Ab-MLNp on the sensitivity of our approach. The optimized system was analyzed, as competitive assay, with different concentrations of sulfapyridine (40 µM, 4 µM, and 2 nM) and with phosphate buffer solution. From data fitting calculations and graphs, it was observed that the EIS showed more linearity when Ab-MLNp was used. This result indicates that the magnetic latex nanoparticles increased the sensitivity of the biosensor.

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Li, Jing, Byung Kun Kim, Kang-Kyun Wang, Ji-Eun Im, Han Nim Choi, Dong-Hwan Kim, Seong In Cho, Won-Yong Lee et Yong-Rok Kim. « Sensing Estrogen with Electrochemical Impedance Spectroscopy ». Journal of Analytical Methods in Chemistry 2016 (2016) : 1–6. http://dx.doi.org/10.1155/2016/9081375.

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This study demonstrates the application feasibility of electrochemical impedance spectroscopy (EIS) in measuring estrogen (17β-estradiol) in gas phase. The present biosensor gives a linear response (R2=0.999) for 17β-estradiol vapor concentration from 3.7 ng/L to 3.7 × 10−4 ng/L with a limit of detection (3.7 × 10−4 ng/L). The results show that the fabricated biosensor demonstrates better detection limit of 17β-estradiol in gas phase than the previous report with GC-MS method. This estrogen biosensor has many potential applications for on-site detection of a variety of endocrine disrupting compounds (EDCs) in the gas phase.

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Antunes, Rafael Souza, Douglas Vieira Thomaz, Luane Ferreira Garcia, Eric de Souza Gil, Vernon Sydwill Sommerset et Flavio Marques Lopes. « Determination of Methyldopa and Paracetamol in Pharmaceutical Samples by a Low Cost Genipa americana L. Polyphenol Oxidase Based Biosensor ». Advanced Pharmaceutical Bulletin 9, n^o 3 (1 août 2019) : 416–22. http://dx.doi.org/10.15171/apb.2019.049.

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Purpose: Jenipapo fruit (Genipa americana L) is a natural source of polyphenol oxidases (PPOs) whose potential in pharmaceutical analysis is noteworthy. Henceforth, this work reports the electrochemical study of a low-cost PPO-based biosensor produced from the crude extract of Jenipapo fruits and accounts a practical approach to employ this biosensor in the determination of methyldopa and paracetamol in pharmaceutical samples. Methods: In order to investigate the electrochemical properties of the biosensor, theoretical and practical approaches were employed, and both samples and the biosensor were analyzed through electrochemical impedance spectroscopy (EIS) and voltammetric techniques, namely: differential pulse voltammetry (DPV) and cyclic voltammetry (CV). Results: showcased that the biosensor presented good analytical features, as well as low detection limits (8 μmol L-1 for methyldopa and 5 μmol L-1 for paracetamol). The relative standard deviation was less than 5% mid-assay. Conclusion: The use of this biosensor is a reliable, low cost and useful alternative in the pharmaceutic determination of phenolic drugs (e.g. methyldopa and paracetamol).

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Yang, Jie, Dawei Li, Zengyuan Pang et Qufu Wei. « Laccase Biosensor Based on Ag-Doped TiO2 Nanoparticles on CuCNFs for the Determination of Hydroquinone ». Nano 11, n^o 12 (décembre 2016) : 1650132. http://dx.doi.org/10.1142/s1793292016501320.

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A novel nanomaterial composed of copper and carbon nanofibers (CuCNFs) decorated with Ag-doped TiO2 (Ag–TiO[Formula: see text] nanoparticles was prepared through electrospinning, carbonization and solvothermal treatment. The composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The obtained composites were mixed with laccase and Nafion to construct novel hydroquinone biosensor. The electrochemical behavior of the novel biosensor was studied using cyclic voltammetry (CV) and chronoamperometry. The results demonstrated that the biosensor possessed a wide detection linear range (1.20–176.50[Formula: see text][Formula: see text]M), a good selectivity, repeatability, reproducibility and storage stability. This work provides a new material to design more efficient laccase (Lac) based biosensor for hydroquinone detection.

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Zhou, Yong. « Novel Approach to Fabricate an Amperometric Biosensor for Glucose Based on Nafion, Azure І and Gold Nanoparticles ». Advanced Materials Research 345 (septembre 2011) : 331–33. http://dx.doi.org/10.4028/www.scientific.net/amr.345.331.

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A novel approach to fabricate an amperometric biosensor for the detection of glucose was described. By means of self-assembled technique and the opposite-charged adsorption, Nafion(Naf), Azure І (Azu), gold nanoparticles (nano-Au) and glucose oxidase (GOD) were immobilized on the gold electrode subsequently. The GOD immobilized on the nano-Au monolayer was stable and retained its functional activity. The stepwise self-assemble procedure of the immunosensor was further characterized by means of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The factors influencing the performance of the resulting biosensor were studied in detail. The biosensor could detect the glucose in a range of 5.1×10-6~4.0×10-3mol/L.

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Thèses sur le sujet "EIS-biosensor"

Taing, Meng-Houit. « Characterisation and Fabrication of a Multiarray Electrolyte-Insulator-Semiconductor Biosensor ». Thesis, Griffith University, 2009. http://hdl.handle.net/10072/365195.

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Label free detection methods are preferred in biological sensing applications due to their convenience, low reagent usage, and minimal equipment dependence. EIS (Electrolyte-Insulator-Semiconductor) is a type of biosensor that achieves this through the sensing of the intrinsic charges present within a biological entity such as a cell or DNA. The charge generates a field which modulates the width of the depletion region within the semiconductor and can be detected using capacitance measurements. To enable the system to be more functional, a chip containing an array of biosensors allows the detection of multiple biological entities simultaneously, leading to a faster and more convenient system. Furthermore, if the characteristics of the each sensor are identical, a single sensor maybe chosen as a reference (an isolated sensor used to measure background noise and drift) to eliminate problems relating to drift and solution background noise. These issues have been addressed by developing a simple and cost effective EIS multi-array biosensor using standard saw cutting tools and industry standard C-V characterisation methods. A lateral shift in the C-V curve represents a change in the depletion region width which is an indication of charge presence. Polyelectrolytes are the main type of charge species used to characterise the system. Initial tests began with a single sensor in a controlled environment using custom made apparatus and equipment for a high level of control. Results indicate a linear response to the charged species across a range of concentrations which confirmed its usefulness in a biosensing application. The approximate sensitivity of the device was determined to be 20mV voltage shift per 50µM of PE added. Device sensitivity was shown to have improved by 23% when the C-V curve was used to identify substrates with lower doping concentrations (that gave a steeper C-V gradient in the depletion region) compared to a higher doped substrate. The single sensor was improved by fabricating multiple electrodes on a single chip using anodic bonding processes coupled with saw cutting methods to create finger-like structures. It demonstrated similar characteristics to the single sensor system with the advantage of having more than one sensor on a single chip. A good level of consistency was found across all sensors (within 2%) which allow accurate comparisons to be made between sensors with low calibration requirements. As a result, a reference sensor can be integrated into the system for cancelling out noise, solution background and drift. The study also shows that the device responds immediately to charges after a 10 minute polyelectrolyte adsorption period, allowing it to be a relatively fast and rapid system. Future packaging solutions such as the realisation of flow-through (for lab-on-chip) and dip systems are a possible application outcome for this technology. These devices can be deployed in areas including industrial monitoring processes, hospital and clinical care services, environmental control and defence sectors for automated, remote, on-site, real-time and portable analysis of specific analytes.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Engineering
Science, Environment, Engineering and Technology
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Wen, Xuejin. « Design, Fabrication, and Characterization of Field-Effect and Impedance Based Biosensors ». The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1308312352.

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Kapita, Patrick Mvemba. « Development of Measurement Systems for Biosensing Applications ». Doctoral thesis, Università di Siena, 2020. http://hdl.handle.net/11365/1111250.

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A health condition called “Oxidative Stress” (OS), resulting from an excessive level of Reactive Oxygen Species (ROS) is a “state harmful to the body, which arises when oxidative reactions exceed antioxidant reactions because the balance between them has been lost”[1] OS appears to be associated with and might be a cause of, many serious diseases such as cardio-vascular accidents, cancer, Parkinson’s and Alzheimer’s[2]. This is not surprising as ROS are free oxygen radicals that can attack lipids, proteins, cellular membranes, enzymes and even modify DNA. Extensive correlation studies have shown that the complex impedance spectrum of blood samples from patients diagnosed with an OS syndrome differs significantly from the spectra obtained from the blood of healthy people, which is quite normal as the presence of an excessive amount of ROS should affect the physico-chemical properties of a blood sample. Measuring the complex impedance spectrum of a blood sample can be done quickly by means of low-cost electronic devices, making possible and affordable the early detection of OS among a large population. In order to quantitatively evaluate the OS, the impedance spectra being insufficient, the concentration of oxidative stress markers such as hydrogen peroxyde, malondialdehyde or F2 isoprostanes needs to be measured. Such measurements can, for instance, be used for monitoring the severity of a disease during a treatment. These concentration measurements are traditionally based upon analytical techniques but recently biosensors acting as transducers transforming directly a specific biochemical reaction into a measurable signal have been developed. They are essentially obtained by modifying the surface of metal or carbon electrodes using biomaterials such as enzymes antibodies or DNA that allow bindings or catalytic reactions with other specific biomaterials to occur on the surface of the electrodes. The resulting modifications of the electrical properties of the medium separating the electrodes can be analyzed through ad-hoc electronic and signal processing systems to yield the desired concentration. Biosensors have the advantages of rapid analysis, low-ost and high-precision. They are widely used in various fields, such as medical care, disease diagnosis and food analysis [3]. Hydrogen peroxide (H2O2) generated by cellular processes directly via two-electron reduction of molecular oxygen or indirectly via dismutation of superoxide, is the most widely studied ROS and its overproduction results in OS. Therefore, an ability to quantify the level of hydrogen peroxide and by ricochet the assessment of oxidative stress can be useful in order to assess certain health conditions occurring inside the body and as a result, an integrated electrochemical biosensor coupled with the hydrogen peroxide quantification can become a practical solution as a point of care device at home[4] Most of the time, H2O2 biosensors are based on HRP (Horseradish peroxidase) which is the most commonly used enzyme in the design of biosensors that can supervise the activity of oxidases and determine in terms of concentration, oxidase substrate such as lactate oxidase, cholesterol oxidase, or glucose oxidase, which all induce the production of hydrogen peroxide (HRP’s substrate). In the first part of this research, we explore the development of low-cost and compact measurement systems aiming to determining the impedance of biological samples as they grant access to information from electrical cellular characteristics. It is indeed possible to measure capacitance or conductance that are dependent on the health state of cells. The development of such measurement systems allowing the portability of biological essays requires sensitive electronics. Afterward, in the second part of our work, we explore the design of an electrochemical biosensor by immobilizing an enzyme (HRP) onto the surface of golden electrodes in order to detect and assess the analyte, hydrogen peroxide (H2O2). We also discuss the design of a potentiostat readout circuit to measure and convert the biosensor’s current. The combined results of the two parts of this work can be considered as a first prototype of a low cost and robust instrument easy to use in the field, away from a biological laboratory, with the goal of reaching the so called “point of care diagnostic” [5] The present thesis is organized as follows: Chapter I, introduces the present thesis. In Chapter II, we provide an overview in the field of biosensing technology. Chapter III deals with the design of a portable EIS measurement system to investigate reactive oxygen species in blood. Chapter IV presents an improved version of the previously designed instrument. Moreover, it points out the significance of EIS-based blood analysis through relevant medical diagnosis parameters such as hematocrit and erythrocyte sedimentation rate, extracted from the measured impedance spectra. In Chapter V we discuss on one hand the design of the H2O2 biosensor, and on the other hand the realization of the front-end circuit of the amperometric sensor. Finally, in Chapter VI, a conclusion is drawn..

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Fuku, Xolile Godfrey. « Cytochrome C biosensor for the determination of trace level arsenic and cyanide compounds ». Thesis, University of the Western Cape, 2011. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_4183_1319807269.

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In this work, an electrochemical method based on a cyt c biosensor has been developed, for the detection of selected arsenic and cyanide compounds. Boron Doped Diamond (BDD) electrode was used as a transducer, onto which cyt c was immobilised and used for direct determination of Prussian blue, potassium cyanide and arsenic trioxide by inhibition mechanism. The sensitivity as calculated from cyclic voltammetry (CV) and square wave voltammetry (SWV), for each analyte in phosphate buffer (pH= 7) was found to be (1.087- 4.488 Ã10-9 M) and the detection limits ranging from 0.0043- 9.1 Î¼M. These values represent a big improvement over the current Environmental Protection Agency (EPA) and World Health Organisation (WHO) guidelines.

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« A Multiplexing Immunosensor for the Quantification of Cytokine Biomarkers ». Doctoral diss., 2012. http://hdl.handle.net/2286/R.I.15805.

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abstract: Biosensors offer excellent diagnostic methods through precise quantification of bodily fluid biomarkers and could fill an important niche in diagnostic screening. The long term goal of this research is the development of an impedance immunosensor for easy-to-use, rapid, sensitive and selective simultaneously multiplexed quantification of bodily fluid disease biomarkers. To test the hypothesis that various cytokines induce empirically determinable response frequencies when captured by printed circuit board (PCB) impedance immunosensor surface, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods were used to test PCB biosensors versus multiple cytokine biomarkers to determine limits of detection, background interaction and response at all sweep frequencies. Results indicated that sensors for cytokine Interleukin-12 (IL-12) detected their target over three decades of concentration and were tolerant to high levels of background protein. Further, the hypothesis that cytokine analytes may be rapidly detected via constant frequency impedance immunosensing without sacrificing undue sensitivity, CV, EIS, impedance-time (Zt) methods and modeling were used to test CHITM gold electrodes versus IL-12 over different lengths of time to determine limits of detection, detection time, frequency of response and consistent cross-platform sensor performance. Modeling and Zt studies indicate interrogation of the electrode with optimum frequency could be used for detection of different target concentrations within 90 seconds of sensor exposure and that interrogating the immunosensor with fixed, optimum frequency could be used for sensing target antigen. This informs usability of fixed-frequency impedance methods for biosensor research and particularly for clinical biosensor use. Finally, a multiplexing impedance immunosensor prototype for quantification of biomarkers in various body fluids was designed for increased automation of sample handling and testing. This enables variability due to exogenous factors and increased rapidity of assay with eased sensor fabrication. Methods were provided for simultaneous multiplexing through multisine perturbation of a sensor, and subsequent data processing. This demonstrated ways to observe multiple types of antibody-antigen affinity binding events in real time, reducing the number of sensors and target sample used in the detection and quantification of multiple biomarkers. These features would also improve the suitability of the sensor for clinical multiplex detection of disease biomarkers.
Dissertation/Thesis
Ph.D. Bioengineering 2012

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Actes de conférences sur le sujet "EIS-biosensor"

Taing, Meng, et Denis Sweatman. « Fabrication techniques for an arrayed EIS biosensor ». Dans 2009 11th Electronics Packaging Technology Conference (EPTC). IEEE, 2009. http://dx.doi.org/10.1109/eptc.2009.5416557.

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Taing, M., et D. Sweatman. « Microfabricated EIS biosensor for detection of DNA ». Dans Microelectronics, MEMS, and Nanotechnology, sous la direction de Dan V. Nicolau. SPIE, 2005. http://dx.doi.org/10.1117/12.638652.

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Tseng, Shin-Hua, Dion T. Tseng, Tzu-Cheng Lee, Tsai-Mu Cheng, Jyh-Yuan Yang, Ruo-Yu Hsieh, Chuan-Mei Tsai et Chia-Ching Chang. « Ultra Sensitive Detection of Eneterovirus 71 by Modified Electrochemical Impedance Spectroscopy ». Dans ASME 2010 First Global Congress on NanoEngineering for Medicine and Biology. ASMEDC, 2010. http://dx.doi.org/10.1115/nemb2010-13143.

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The enterovirus 71 (EV71) has threatened Taiwan for more than ten years. Since traditional diagnostic methods are complicated, time consuming, and high-qualified personnel required. Therefore, a new detection process is highly desired. In this study, a high sensitive PC-based electrochemical analyzing system with a functionalized nano-gold modified immunological electrode are developed to detect EV71. Immobilizing specific EV71 polyclone antibodies, which is developed by center for disease control (CDC) Taiwan, onto nano gold of sensing electrode, the affinity interaction of the immobilized antibody with the specific antigen is identified quickly by electrochemical impedance spectrum (EIS) within 20 minutes. The detection limit of this EIS analysis was as low as 50 copy per ml (∼sub-atto molar). In summary, a biosensor and analyzing system based on EIS has been developed to identify EV71 with efficiency, high sensitivity and specificity.

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Wang, Gou-Jen, Yi-Fen Liu et Chia-Che Wu. « In-Vitro Allergy Detection Using a Silver Nanoparticle Modified Nanostructured Biosensor ». Dans ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/detc2012-70299.

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IgE (Immunoglobulin E) in the serum of an asthma patient is a useful index for allergy diseases. In this study, a nanostructured biosensor having uniformly deposited gold nanoparticles (GNPs) as the sensing electrode was used for fast and low serum consuming detection of the IgE in allergy patients’ serum. To enhance the charge transferring efficiency of the biosensor, silver nanoparticles (SNPs) were deposited on the GNP layer. The group 2 allergen, Der p2, was used as the probe to detect IgE. To ensure the specificity of detection, the affinity purified goat anti-Human IgE antibody was further immobilized to the IgE. After immobilizing the anti-IgE on the sensor, the electrochemical impedance spectroscopy (EIS) analysis was implemented to examine the concentration of the target IgE in terms of a Nyquist plot. Blood serum samples with known allergy levels detected by the commercially available ImmunoCAP were used for the verification of the sensor. It is observed that the difference of the charge transfer resistance (ΔRet) between the Der p2 immobilized electrode and the anti-IgE bonded electrode for each individual serum sample closely correlates to its ImmunoCAP class. The blood serum detection results indicate that the presented nanostructured biosensor is able to detect a patient’s allergy level with low sample consumption, short sample preparation time, and quick processing.

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Lin, Ying-Ting, Iren Kuznetsova et Gou-Jen Wang. « Genetically Modified Soybean Detection Using a Biosensor Electrode With Self-Assembled Gold Nanoparticles on a Micro Hemisphere Array ». Dans ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/detc2019-97112.

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Abstract Gene transfer technology changes some of the characteristics of crops. However, genetically modified foods have been reported to have an impact on human health. We proposed a cost effective and highly sensitive biosensor electrode with self-assembled monolayer of gold nanoparticle on a micro hemisphere array to detect genetically modified soybean. An ordered array of micro hemispherical features was formed on a 6-inch reclaimed silicon wafer using photolithography. Then, a thin gold layer was sputtered onto the hemispheres. The wafer was then immersed into a 5 mM ethanol solution of 1,6-hexanedithiol (1,6-HDT) to enable the attachment of one thio-end of 1,6-HDT to the thin gold layer. Next, a colloidal gold (15 nm) solution was dripped onto the wafer and baked on a hot plate in such a way that the monolayer of gold nanoparticles could self-assemble on the 1,6-HDT surface. Finally, we used electrochemical impedance spectroscopy (EIS) analysis to detect genetically modified soybean. Experimental results demonstrate that our biosensor can successfully distinguish the genetically modified soybeans from the normal ones.

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Wang, Wei-Jhen, Chia-Hwa Lee, Chin-Wen Li, Stephen Liao, Fuh-Jyh Jan et Gou-Jen Wang. « Direct Label Free Detection of Orchid Virus Using a Micro/Nano Hybrid Structured Biosensor ». Dans ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/detc2019-97198.

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Abstract In this study, a label-free detection approach for effective detection of the odontoglossum ringspot virus (ORSV) infected orchids has been developed. We used semiconductor fabrication process to fabricate 1,810 micro/nano hybrid structured sensing electrodes on a 8 inch reclaimed wafer. The self-assembled monolayer (SAM) process was then employed to sequentially modify the electrode surface with 11-mercaptoundecanoic acid (11-MUA), 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC)/ N-hydroxysuccinimide (NHS), anti-ORSV, and ORSV. EIS was conducted for the ORSV concentration detection. Experimental results demonstrated that the ORSV concentration in a virus infected orchid leaf could be effectively detected. When compared with the ELISA kit, our device possesses a wider linear detection range (0.5–50,000 ng/mL) and a higher sensitivity. The specificity of our device on ORSV detection was also confirmed. Our sensing device retains advantages, such as label-free, lower amounts of the antibody and target sample required, low detection time, and a wider linear detection range. Those results imply the feasibility of our sensing device in field applications.

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Chen, Chun-Cheng, et Gou-Jen Wang. « PCR Free Detection of Hepatitis B Virus DNA Using a Nanostructured Impedance Biosensor ». Dans ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-34866.

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In this study, a PCR free technique for effective detection of hepatitis B virus (HBV) DNA obtained directly from clinical samples was presented. The honeycomb-like barrier layer of an anodic aluminum oxide (AAO) film having a uniform nanohemisphere array was used as the substrate of the sensing electrode. A gold thin film about 30 nm thick was radio-frequency (RF) magnetron sputtered onto the AAO barrier-layer surface as the electrode for the successive deposition of gold nanoparticles (GNPs) on the hemisphere surface. A specially designed single-strand 96-mer gene fragment of the target genomic DNA of HBV based on the genome sequences of HBV from the National Center for Biotechnology Information (NCBI) was immobilized on the nanostructured electrode as the capture probe. Complementary target HBV DNA (3020–3320 mer) obtained from clinical samples were further hybridized to the sensing probes. Detection results through electrochemical impedance spectroscopy (EIS) illustrate that two dynamic linear ranges, 0–103 and 103–105 copies/mL, having R2 values of 0.973 and 0.998, respectively, could be obtained. A detection limit of 186 copies/mL could be achieved. The proposed simple and high performance HBV DNA detection technique in this study is highly feasible for future clinical applications.

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