Bioactive surface design based on conducting polymers and applications to biosensors

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Kimya Bölümü, Türkiye

Tezin Onay Tarihi: 2012

Öğrenci: FULYA EKİZ

Danışman: LEVENT KAMİL TOPPARE

Özet:

An underlying idea of joining the recognition features of biological macromolecules to the sensitivity of electrochemical devices has brought the concept of biosensors as remarkable analytical tools for monitoring desired analytes in different technological areas. Over other methods, biosensors have some advantages including high selectivity, sensitivity, simplicity and this leads to solutions for some problems met in the measurement of some analytes. In this context, conducting polymers are excellent alternatives with their biocompatibility and ease of applicability for an efficient immobilization of biomolecules in preparing biosensors. Using several materials and arranging the surface properties of the electrodes, more efficient and seminal designs can be achieved. In this thesis, it is aimed to create new direct biosensors systems for the detection of several analytes such as glucose and pesticides thought to be harmful to the environment. Recently synthesized conducting polymers (polyTBT); (poly(2-dodecyl-4,7-di(thiophen-2-yl)-2H-benzo[ d][1,2,3]triazole) and (poly(TBT 6 -NH2 ); poly(6-(4,7-di(thiophen-2-yl)-2H-benzo[d][1,2,3]triazol-2-yl)hexan-1-amine) were utilized as a matrices for biomolecule immobilization. After successful electrochemical deposition the polymers on the graphite electrode surfaces, immobilization of glucose oxidase (GOx) and choline oxidase (ChO) were carried out. Amperometric measurements were recorded by monitoring oxygen consumption in the presence of substrates at -0.7 V. The optimized biosensors showed a very good linearity with rapid response times and low detection limits (LOD) to glucose and choline. Also, kinetic parameters, operational and storage stabilities were determined. Finally, designed biosensor systems were applied for glucose and pesticide detection in different media.