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Title: Development of nanostructured surfaces for the immobilisation of enzymes on screen printed biosensors
Author: Pchelintsev, Nikolay Andreevich
Awarding Body: University of Leeds
Current Institution: University of Leeds
Date of Award: 2008
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During the last decade, the requirement of medical, food and environmental analysis for fast, reliable and inexpensive screening methods has given rise to increasing interest in the field of disposable amperometric biosensors. Screen-printed carbon electrodes (SPCE) are the most attractive basis for the construction of such devices as they combine good electrochemical properties with low manufacturing cost. However, effective immobilisation of enzymes on the surface of SPCE is difficult due to the inert nature of the carbon material. This thesis shows that poly(ethyleimine) (PE!) deposited onto the screen-printed carbon surface can be used as a universal and versatile platform for the multipoint electrostatic adsorption of various enzymes. Such electrostatic immobilisation can be significantly stabilised by biomimetic condensation of silicic acid which reinforces the PEI-enzyme complexes through gentle, non-covalent concreting of the polymeric backbone with silica. Another important problem in the assembly of amperometric biosensors on the basis of SPCE is the signal generation since many redox reactions which govern the sensitivity of an amperometric biosensor, e.g. oxidation of hydrogen peroxide, proceed with difficulty on the screen-printed carbon surface. In order to address this issue, simple cost-effective techniques for doping SPCE with redox mediators, cobalt phthalocyanine and Prussian Blue, have been developed. When applied to PEI-modified electrodes these techniques allowed the construction of amperometric biosensors sensitive to glucose, acetylcholine or organophosphate inhibitors.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available