Dissertations / Theses on the topic 'Enzyme-based biosensor'
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Dewa, Andrew Steven. "A silicon-based enzyme biosensor utilizing Langmuir-Blodgett film immobilization." Case Western Reserve University School of Graduate Studies / OhioLINK, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=case1057002686.
Full textVeisi, Zeinab. "Detection of COX-2 enzyme using highly sensitive electrospun polyaniline nanofiber-based biosensor." Thesis, Wichita State University, 2013. http://hdl.handle.net/10057/6846.
Full textThesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering
Sumner, Claire. "Development of a biosensor based on enzyme-catalysed degradation of thin polymer films." Thesis, University of Sheffield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341818.
Full textSok, Vibol. "Amperometric enzyme-based detection of agriculturalpesticides on novel carbon nano-onion composites." Doctoral thesis, Universitat Rovira i Virgili, 2018. http://hdl.handle.net/10803/665119.
Full textActualmente existe una gran preocupación sobre el uso de pesticidas en la agricultura y sus posibles efectos secundarios. Esto hace que el desarrollo de sistemas de detección sensibles y robustos sea un paso importante en esta dirección. Por otro lado, las nano-cebollas de carbono (CNOs) son materiales muy atractivos y prometedores con estructuras definidas y propiedades electroquímicas notables que apenas se han estudiado en biosensores. El objetivo general de esta tesis es estudiar la interacción de diferentes plaguicidas con peroxidasa y tirosinasa con el objetivo de desarrollar biosensores para su detección basados en electrodos modificados con CNOs. Para lograr este objetivo general, se ha estudiado: 1) la inhibición de las actividades de peroxidasa y tirosinasa por tres de los plaguicidas más utilizados (2,4-D, 2,4,5-T y glifosato), 2) el uso de CNOs oxidadas como soportes para la inmovilización de enzimas y un estudio de la actividad y estabilidad de las enzimas inmovilizadas, 3) el desarrollo de biosensores electroquímicos para detección de los plaguicidas antes citados basados en los electrodos modificados con composites conteniendo enzimas y CNOs. Esta tesis es, por lo tanto, una contribución a un campo de rápido crecimiento relacionado con el desarrollo de nuevas clases de nanomateriales de carbono que tiene como objetivo ampliar sus aplicaciones actuales en la construcción de sistemas de detección novedosos con mejores prestaciones.
There is currently a strong concern on the use of pesticides in agriculture and their possible side effects. This makes the development of sensitive and robust detection systems an important step in this direction. On the other hand, carbon nano-onions are very attractive and promising materials with defined structures and remarkable electrochemical properties that have been scarcely studied in biosensing. The overall objective of this thesis is to study the interaction of different pesticides with peroxidase and tyrosinase with the aim to develop biosensors for pesticide detection based on CNO-modified electrodes. To achieve this general objective, the following aspects have been focused on: 1) the inhibition of peroxidase and tyrosinase activities by three of the most used pesticides (2,4-D, 2,4,5-T and glyphosate), 2) the use of oxidized CNOs as supports for the immobilization of enzymes and a study of the activity and stability of the immobilized enzymes, 3) the development of electrochemical biosensors for pesticide detection based on the prepared CNO-enzyme modified electrodes. This thesis is thus a contribution to a rapidly growing field related with the development of new classes of carbon nano-onion based nanomaterials that aims at expanding their current applications in the construction of novel detection systems with improved performances.
Campbell, Alan S. "Enzymatic Biosensor and Biofuel Cell Development Using Carbon Nanomaterials and Polymer-Based Protein Engineering." Research Showcase @ CMU, 2017. http://repository.cmu.edu/dissertations/859.
Full textSanghera, G. S. "Electrochemical biosensors for food based systems (enzyme electrodes)." Thesis, Cardiff University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376828.
Full textBerners, Manfred Otto Maria. "Development of enzyme based sensors for use in neurochemistry." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307034.
Full textMartin, Stacey Peter. "Enzyme-based quartz crystal biosensors for analytes of biomedical significance." Thesis, University of Surrey, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402575.
Full textPaliwal, Sheetal Simonian Aleksandr L. "Development of enzyme-based biosensors for the detection of organophosphate neurotoxins." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/FALL/Materials_Engineering/Dissertation/Paliwal_Sheetal_0.pdf.
Full textÖh, Clara. "Biosensor based on immobilized amine transaminase for detection of amphetamine." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278584.
Full textAmintransaminaser (ATA) katalyserar överförandet av en amingrupp från en molekyl och ersätter en keton eller aldehyd med den amingruppen, amingruppen på amin-donatorn ersätts med en keton eller aldehyd. Det här enzymet, ATA från Chromobacterium violaceum (CvATA), har tidigare använts för att katalysera en reaktion som involverar amfetamin, därför skulle detta enzym kunna användas på amfetamin. Produkten av reaktionen absorberar i UV spektrumet och kan mätas med en spektrofotometer. Målet med projektet var att utforska möjligheten av att använda CvATA i en biosensor för att detektera amfetamin. En litteraturstudie på kommersiellt tillgängliga bärbara biosensorer genomfördes, aktiviteten av det fria enzymet testades mot två substrat, metylbenzylamin (MBA) och amfetamin. Information samlades om immobiliseringstekniker, material, och ytfunktionalisering gjordes för att välja ut lämpliga metoder för immobilisering av CvATA. Två immobiliseringsmetoder föreslogs och en av metoderna, immobilisering via enzymets His6-tagg och Ni2+ joner på ytan, testades för enzymaktivitet mot MBA. Enzymaktiviteten av det fria enzymet i lösning mot MBA var i samma storleksordning som tidigare rapporterad enzymaktivitet, men ingen enzymaktivitet mot amfetamin kunde observeras. Ingen aktivitet kunde observeras för det immobiliserade enzymet, men det kan vara på grund av designen på experimentet, fler experiment behöver göras för att kunna dra några fler slutsatser.
Khurana, Manpreet Kaur. "The development of enzyme-based metallised carbon epoxy biosensors for physiological applications." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408521.
Full textSoldatkin, O. O., I. S. Kucherenko, Kasap B. Ozansoy, Kurc B. Akata, A. P. Soldatkin, and S. V. Dzyadevych. "Conductometric Biosensor Based on Urease, Adsorbed on Silicalite for Determination of Urea in Serum Samples." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35478.
Full textZhou, Dao Min. "An investigation of some electrochemical characteristics of enzyme based disposable biosensors and other relevant electrodes." Thesis, University of Ulster, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242072.
Full textReyes, de Corcuera José Ignacio. "Increased sensitivity of enzyme-based amperometric glucose biosensors and their application as time-temperature integrators." Online access for everyone, 2004. http://www.dissertations.wsu.edu/Dissertations/Spring2004/J%5FDe-Corcuera%5F050404.pdf.
Full textKartal, Mujgan. "Biosensor Based On Interpenetrated Polymer Network Of Alginic Acid And Poly(1-vinylimidazole )." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609286/index.pdf.
Full textjgan M.S., Department of Chemistry Supervisor : Prof. Dr. Levent Toppare January 2008, 63 pages A new proton conductor polymer was prepared using alginic acid (AA) and poly (1-vinylimidazole) (PVI). The polymer network was obtained by mixing AA and PVI at various stoichiometric ratios, x (molar ratio of the monomer repeat units). The AA/PVI network was characterized by elemental analysis (EA) and FT-IR spectroscopy. Potential use of this network in enzyme immobilization was studied. Enzyme entrapped polymer networks (EEPN) were produced by immobilizing invertase and tyrosinase (PPO) in the AA/PVI network. Additionally, the maximum reaction rate (Vmax) and Michaelis-Menten constant (Km) were investigated for the immobilized invertase and enzymes. Also, temperature and pH optimization, operational stability and shelf life of the polymer network were examined.
Young, Sarah Jane. "The detection of organic aqueous pollutants using inhibition of enzyme activity : a model system based on lactate dehydrogenase and pentachlorophenol." Thesis, University of the West of England, Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311878.
Full textLiang, Pingping. "Gold Nanoparticle-Based Colorimetric Sensors for Detection of DNA and Small Molecules." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2595.
Full textWilson, Lindsay. "Electrochemical immunosensor based on cyclodextrin supramolecular interactions for the detection of human chorionic gonadotropin." Thesis, University of the Western Cape, 2012. http://hdl.handle.net/11394/3995.
Full textGlucose oxidase (GOx) and horseradish peroxidase (HRP) are important enzymes for the development of amperometric enzyme linked immunosensors. The selectivity of each enzyme towards its analyte deepens its importance in determining the sensitivity of the resultant immunosensor. In designing immunosensors that have customized transducer surfaces, the incorporation with FAD and iron based enzymes ensures that electron kinetics remains optimal for electrochemical measurement. Various different immobilization strategies are used to produce response signals directly proportional to the concentration of analyte with minimal interferences. The combination of self-assembled monolayers and supramolecular chemistry affords stability and simplicity in immunosensor design. In this work, two electrochemical strategies for the detection of human chorionic gonadotropin(hCG) is presented. This involves the modification of a gold surface with a thiolated β-cyclodextrin epichlorohydrin polymer (βCDPSH) to form a supramolecular inclusion complex with ferrocene (Fc)-functionalised carboxymethyl cellulose polymer (CMC). Cyclic voltammetry indicated that ferrocene is in close proximity to the electrode surface due to the supramolecular complex formed with βCDPSH. Furthermore, strategy (a) for the detection of hCG used α-antihCG labelled (HRP) as reporter conjugate. Strategy (b) maintained the CMC bifunctionalised with Fc and recognition antibody for hCG hormone. However, the system was functionalised with a HRP enzyme and detection is done by using GOx reporter conjugates for in situ production of hydrogen peroxide. The reduction of H2O2 was used for the amperometric detection of hCG by applying a potential of 200 mV. The sensitivity and limit of detection of both strategies were calculated from calibration plots. For strategy (a) the LOD was found to be 3.7283 ng/mL corresponding to 33.56 mIU/mL and a sensitivity of 0.0914 nA ng-1 mL-1. The corresponding values for strategy (b) are 700 pg/mL (6.3 mIU/mL) and 0.94 nA ng-1 mL-1.
Andersson, Simon. "Point-of-care beta-hydroxybutyrate determination for the management of diabetic ketoacidosis based on flexible laser-induced graphene electrode system." Thesis, Linköpings universitet, Sensor- och aktuatorsystem, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-179116.
Full textPai, Hong-Cheng, and 白洪政. "Digital Simulation Analysis of the Enzyme Activity on the Electrode-based Biosensor and Its Miniaturization." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/46007722641979007969.
Full textZhang, Yufen. "Development of an enzyme immobilization platform based on microencapsulation for paper-based biosensors." Thèse, 2011. http://hdl.handle.net/1866/9883.
Full textBiosensing paper attracts increasing attention due to its benefits of being simple, visible, portable and useful for detecting various contaminants, pathogens and toxins. While there has been no bioactive paper commercialized since glucose paper strips developed in the fifties, many research groups are working to immobilize biomolecules on paper to achieve a bioactive paper that is affordable and has good shelf life. The goal of this research is to develop some highly useful bioactive paper that could, for example, measure blood glucose, or immediately detect and simultaneously deactivate pathogens such as neuraminidase and E.coli. Previously, bioactive paper was produced either through physically absorbing biorecognition elements or printing bio-ink onto paper substrate. Our methodology for fabrication of bioactive paper strips is compatible with existing paper making process and includes three procedures: the fabrication of microcapsules, enzyme or antibody microencapsulation, immobilization of enzymes or antibody-entrapped microcapsules into paper pulp. The first step, in fabricating of bioactive paper strips is to produce biocompatible and inexpensive microcapsules with suitable parameters. To do so, two types of microencapsulation methods were compared; the emulsion method and the vibration nozzle method accomplished with an encapsulator. The parameters for producing optimal microcapsules with both methods were studied. Factors that affect their diameter, wall thickness, shell pore size, encapsulation efficiency and membrane compositions were also discussed. By comparison, microcapsules prepared with poly(ethyleneimine) (PEI) by the emulsion method exhibit properties that were more suitable for enzyme encapsulation and paper making process, whereas the microcapsules prepared by the vibration nozzle method were too big to be immobilized within paper pulp, and had lower encapsulation efficiency, enzymatic activity and productivity. Thus the emulsion method was chosen for subsequent experiments such as enzyme and antibody microencapsulation and bacterial vaginosis (BV) paper preparation. Microcapsules made by the emulsion method were semi-permeable in that the diffusion of substrate and product molecules were allowed freely across the membranes but the encapsulated enzymes would be retained inside. Glucose oxidase from Aspergillus niger (GOx) and laccase from Trametes versicolor (TvL) microcapsules showed high encapsulation efficiency, but the encapsulation process caused a severe decrease in the specific activities of both enzymes. Results from circular dichroism (CD) studies, fluorescence properties, enzymatic activities of free enzymes and Michaelis-Menten behavior demonstrated that the Vmax decrease for GOx was due to the restriction of diffusion across microcapsule membranes with pore size less than 5 nm. The microencapsulation process improved the thermal stability of GOx but decreased that of laccase. Bioactive papers were fabricated either by incorporating microcapsules containing different enzymes or empty microcapsules soaked in substrate and enhancer solution into the paper pulp during the sheet making process. Both the GOx and the BV paper strips underwent a color change in the presence of glucose and potassium iodide, and sialidase from Clostridium perfringens respectively. Some preliminary studies on antibody sensitized microcapsules, in which antibody was either encapsulated within the PEI microcapsules or conjugated to its membranes, were also performed. Our objective was to establish an enzyme immobilization platform based on microencapsulation techniques for paper based biosensors. Even though our current studies only focused on the microencapsulation of two enzymes, TvL and GOx, as well as the bioactive paper preparation, a similar approach can be applied to other enzymes. We believe that this immobilization method can potentially be employed for bioactive paper preparation on an industrial scale.
Chou, Chwn-Yu, and 周政郁. "A novel strategy for determination of allopurinol based on competitive behavior of oxygen-consumption by dual-enzyme biosensor." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/b2pf6f.
Full text淡江大學
化學學系碩士班
102
Two parallel enzymatic oxygen-consumed reaction including oxidation of hypoxanthine by xanthine oxidase (EC 1.17.3.2) and oxidation of catechol by tyrosinase (EC 1.14.18.1) were utilized to constructed novel allopurinol biosensor. In this project, the concentration increase of allopurinol (inhibitor) would inhibit the activity of enzymatic oxygen-consumption by xanthine oxidase. Subsequently, tyrosinase could divvy more oxygen to produce catechol quinone, and it could be observed that more current response was recorded from electrochemical reduction of catechol quinone at 0.0V (vs. Ag/AgCl). In contrast to the determination of traditional inhibition type which the signal was inverse proportional to the concentration of inhibitor, the signal is proportional to the concentration of allopurinol. Moreover, in this biosensor, the monolayer of enzyme modifier and 0.0V detection potential were adapted to obtains fast response (t90%-10% = 2.9 second) and efficiently avoids common interference of substances that co-exist in serum. This allopurinol biosensor possesses linear range 5μM-100μM (R=0.998) that satisfy with therapeutic range (5-15mg/L), sensitivity is 8.79 nA/μM, detection limit is 1.4μM, the relative standard deviation (RSD) is 4.2%. Allopurinol was used to primary treatment of hyperuricemia and its complication. However, it potentially causes serious hypersensitivity such as Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TENS) on several patients after allopurinol treating. Therefore, the determination of allopurinol is important and necessary for clinical monitoring and quality assurance of pharmacy.
Monteiro, Tiago Carvalho. "Development of point-of-care tests using enzyme (NiR & PON) based electrochemical biosensors." Doctoral thesis, 2020. http://hdl.handle.net/10362/113413.
Full textPinheiro, Tomás Pinto e. Cruz de Oliveira. "Multiplex, Enzyme-free, Colorimetric Paper-based Device for the Measurement of Glucose, Uric Acid and Cholesterol." Master's thesis, 2018. http://hdl.handle.net/10362/56405.
Full textCHEN, JIAN-SYUN, and 陳建勳. "The Research of Integrating the Differential Reference Electrode as well as Magnetic Beads and Graphene Modified in Arrayed Flexible IGZO Glucose Biosensor Based on Microfluidic Framework and the Fabrication of Multifunctional Enzyme Real-Time Sensing System." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/wke9x5.
Full text國立雲林科技大學
電子工程系
104
In this thesis, it was mentioned the enzymatic glucose biosensor was manufactured by using radio frequency sputtering system, thermal evaporation system and screen-printed technology, whose glucose sensing membrane was composed of indium gallium zinc oxide (IGZO) membrane and glucose oxidase (GOx). For enhancing sensing characteristics of enzymatic glucose biosensor, the sensing membrane was modified by graphene oxide (GO) and magnetic beads (MBs) to improve adsorption of enzyme and sensing characteristics. According to experiential results, the average sensitivity and linearity of enzymatic glucose biosensor modified by GO and MBs were 10.391 mV/mM and 0.998, respectively. To demonstrate that sensing membrane was successfully modified by GO and MBs, the electrochemical impedance spectroscopy (EIS) was used to analyze the capability of electron transfer for sensing membranes. The stability, lifetime, interference and detection limit of the enzymatic glucose biosensor modified by GO and MBs were investigated. Finally, the enzymatic glucose biosensor modified by GO and MBs was integrated with the microfluidic framework and the sensing characteristics under dynamic conditions, i.e., solution under flowing condition, were investigated. According to experiential results, under dynamic conditions, the average sensitivity and linearity of enzymatic glucose biosensor modified by GO and MBs were enhanced to 12.383 mV/mM and 0.999, respectively. Furthermore, in order to develop the real-time sensing system applied in measurement of pH value and multifunctional enzyme, the pH sensor as well as enzymatic glucose, lactate and urea biosensor modified by GO and MBs was combined with wireless sensing system to carry out the wireless sensing measurements, and this system complied with ZigBee wireless networking protocol which consisted of the XBee module, Arduino Mega 2560, readout circuit, biosensor and computer was employed to transmit the measurement signals. According to the experimental results, the average sensitivities of the pH sensor as well as enzymatic glucose, lactate and urea biosensor modified by GO and MBs were 50.059 mV/pH, 10.257 mV/mM, 55.747 mV/mM and 2.066 mV/(mg/dl), respectively.
Chou, Nien-Hsuan, and 鄒年烜. "Study and Fabrication on Solid State Enzyme Biosensors Based on Ammonium Ion-Selective Electrodes." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/08771332430971114119.
Full text中原大學
電子工程研究所
92
The detection and determination of urea are the important parameters and great interests in biomedical and clinical analysis applications where a reduced level in urine and an increased concentration in blood are the important indication for renal dysfunction. Although there are direct spectrophotometric methods of urea determination, enzymatic methods are more selective and much more widely used. A potentiometric solid-state urea biosensor prepared by immobilization of urease directly onto the surface of an ammonium ion-selective electrode is described in this paper. The substrate of the ammonium ion-selective electrode is the tin oxide (SnO2) / indium tin oxide (ITO) glass and the enzyme was immobilized by entrapment method on a nonactin membrane incorporated carboxylated polyvinylchloride (PVC-COOH). However, for the quantitative expression for their selectivity is desired, the article employed the selectivity coefficients approach to estimate the selectivity of urea biosensors. In this study, experimental procedures based on the Nicolsky-Eisenman equation were considered. Therefore, the level of influence of the preference of the urea biosensors on the primary ions relative to interfering ions of is determined. According to this paper, urea biosensors based on ammonium ion-selective electrodes respond rapidly and stable within the pH range from pH 6 to pH 7.5. The slope in the linear range (0.026 mM to10 mM) is about 55.56±3.15 mV/decade and the detection limit is 5 μM. Moreover, the use of ammonium ion-selective electrode has the advantage of providing solid-state urea biosensors that are easy to fabricate, good reproducibility and stability, low cost and allow miniaturization configuration.
Shao, Te-Fang, and 邵德芳. "The Study of Biosensors Based on Enzyme Electrode and Its Electrochemical Characteristic Determined by Digital Simulation." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/24520959808607221685.
Full text國立成功大學
醫學工程學系
81
Most of the electrochemical reaction phenomena and its equations are relatively complicate, therefore, it is difficult to estimate the kinetic parameters exactly from some experimental processes. Recently, the digital computer had been designed in high-speed operation and many simulation methods were reported, it promoted the development in bioelectrochemical analysis. Among these researches, the digital simulation systems based on explicit finite difference method was utilized to discuss the electrochemical behaviors and showed the excellent possibilities in each cases containing homogeneous enzyme reactions. Here, we further considered the mechanism of enzyme reaction and diffusion of mass transfer to the simulation process. Now, the electrochemical characteristics of redox compound, an electron transfer mediator, and electrooxidation of NADH based on diaphorase (Dp) and ferrocenylmethylalcohol (FMA) were discussed. The simulated values of diffusion coefficients of FMA and the Michaelis constant of Dp were proved to be extremely agreed to the reported values. At present, we are making an effort on the case of enzyme- immobilized electrode. In this analytical process, the partition number $(\alpha)$ and diffusion coefficient ($D_m$) of mediator in enzyme membrane were required. For this purpose, potential step analysis followed by rotating method was applied. We believe this simulation system would be not only useful in efficiency test of enzyme electrode, but also helpful in finding out the optimal condition for enzyme membrane fabrication.