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Fabrication Of New Amperometric Biosensor

Posted on:2006-06-20Degree:MasterType:Thesis
Country:ChinaCandidate:Y LiuFull Text:PDF
GTID:2168360155455389Subject:Analytical Chemistry
Abstract/Summary:PDF Full Text Request
Biosensors based on enzyme-modified electrodes are valuable in clinical diagnosis, bromatology, environmental monitoring and biochemical analysis. This thesis involves the following subjects relating to hydrogen peroxide biosensor and glucose oxidase biosensor.1) Hydrogen peroxide biosensor was constructed, which was modified by horseradish peroxidase (HRP) based on nanometer-sized Ag colloids and polyvinyl butyral (PVB) as a matrix with the aid of Co(bpy)33+ or Azure C mediator in hydrogen peroxide solution. The factors in the fabrication and manipulation of the sensor are initially studied. Amperometric response of hydrogen peroxide at these biosensors, under optimal preparation and determination conditions, exhibit linear relationships to the concentration of hydrogen peroxide in the range of 1×10-5 to 1×10-2 M and 2.0×10-6 to 6.0×10-3 M. The sensors were highly sensitive to H2O2 with a detection of 2×10-6 M and 8.0 ×10-7M (S/N=3). The sensor exhibited high sensitivity, selectivity and stability.2) A stable electropolymerized methylene blue and neutral red films are electropolymerized on the glassy carbon by the method of cyclic voltammetry, their electrochemical quality is studied extensively in 0.1 mol/L phosphate buffer (pH 7.0). Two typies of glucose biosensors are developed, which glucose oxidase (GOD) had been respectively adsorbed to colloidal gold combined with polyvinyl butyral (PVB) and Nafion, which were immobilized onto the surface of poly(methylene blue) and poly(neutral red) modified glassy carbon electrode. Linear calibration for glucose were obtained respectively in the range 1 ×10-6 3×10-3 M and 1 ×10-5 1.2 ×10-3 M under the optimized conditions. The results show that the Au colloid could larged...
Keywords/Search Tags:biosensor, glucose oxidase, horseradish peroxidase, nanoparticles, electron mediators.
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