A Functional immobilization matrix based on a conducting polymer modified with PMMA/clay nanocomposites and gold nanoparticles : applications to amperometric glucose biosensors

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2014
Kesik, Melis
Designing biosensors for detection of target species in any test solution has attracted keen interest throughout the world. Over the conventional methods biosensors have several advantages which are specific, rapid, and simple to operate, and ease of fabrication with minimal sample pretreatment involved. However, reproducibility and stability are still major drawbacks. To overcome these problems, a suitable immobilization method must be chosen. Conducting polymers serve excellent immobilization platform for biomolecule depositions owing to their biocompatibility, ease of preparation and ability to modify structural properties. Besides, combination of conducting polymers and nanostructures attracted considerable attention in biosensing applications. Modification of the electrode surface with nanostructures leads to increase rate of electron transfer between biomolecules and support material. By this way, effective and stable biosensor design is achieved. In this thesis, a functional polymer, poly(6-(4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2H-benzo[d][1,2,3]triazol-2-yl)hexan-1-amine) poly(BEDOA-6), was utilized as an immobilization matrix for glucose oxidase biosensor construction. Moreover, conducting polymer surface was modified with PMMA/clay nanocomposite material and modified gold nanoparticles to develop two different glucose biosensors. After successful electrochemical deposition of the polymer; poly(BEDOA-6) on the graphite electrode, immobilization of glucose oxidase was carried out. During immobilization, nanostructures were used in biosensor fabrication to achieve the most effective surface design for target biosensors. By applying constant potential, consumption of oxygen concentration in bulk solution was followed using amperometric technique. Surface features of the biosensors were characterized using several techniques like SEM, XPS, TEM, Fluorescence Microscopy. The designed biosensors showed wide linear ranges with low detection limits. Also, kinetic parameters, operational and storage stabilities were determined. Finally, the biosensors were tested on real samples
Citation Formats
M. Kesik, “ A Functional immobilization matrix based on a conducting polymer modified with PMMA/clay nanocomposites and gold nanoparticles : applications to amperometric glucose biosensors,” M.S. - Master of Science, Middle East Technical University, 2014.