The Application Of Nano Silver Colloidal In Amperometric Glucose Oxidase Biosenser

Studies on the application of nano silver colloid in amperometric biosensor are described in this work. The dissertation consists of four chapters.Chapter 1 reviews the development of the studies on nanoparticles in recent years, including the properties and manufacture of nanoparticles, especially the application of nanoparticles in photochemical and electrochemical bioanalysis.Chapter 2 is divided into two parts. Part one studies a new glucose biosensor with naphthol green B as electron mediator. The biosensor is made of a platinum electrode modified by glucucose oxidase in polyvinyl butyral membrane. Electrocatalytic oxidation of glucose at the sensor is determinated with respect to solution pH, temperature and concentration of water-soluble mediator naphthol green B. Under optimal conditions, the sensor displays a good linear response in the concentration range of 8.0+10-4 mol/L-3.6+10-2 mol/L, and the detection limit is 5.0+10-4 mol/L. Besides, the biosensor has fast response, excellent reproducibility and stability. Part two reports that a glucose oxidase electrode is made of a platinum electrode modified by glucose oxidase in polyvinyl butyral membrane and tris(2,2'-bipyridyl)cobalt(III) perchlorate as an electron mediator in the solution. Electrocatalytic oxidation of glucose at the sensor is determined with respect to solution pH, temperature and concentration of water-soluble mediator tris(2,2'-bipyridyl)cobalt(III) perchlorate. Under optimal conditions, the sensor displays a wide linear response in the concentration range of 6+10-6 mol/L-1.0 +10-4 mol/L with a low detection limit of 3+10-6 mol/L, excellent reproducibility and stability.Chapter 3 describes the preparation of silver sols with the reduction of AgNO3 byNaBH4. The sols is bright yellow and stable during a month and a half. Silver sols are charaterized by a transmission electron microscopy(TEM) and ultraviolet-visible spectrophotometer(UV). The result indicates that the silver particles are approximately spherical and monodispersed with an average diameter of ca.15nm.Chapter 4 comprises two part. Part reports on the manufacture and characterization of glucose oxidase -silver sol-polyvinyl butyral modified platinum electrodes with naphthol green B as an electron transfer mediator in the glucose solution. The response of the glucose electrode is surveyed by measuring cyclic voltammetric peak current values under aerobic solution conditions. Electrocatalytic oxidation of glucose at the electrode is evaluated with respect to temperature, solution pH and concentration of naphthol green B. A linear response of the sensor in the wide range of 1.0+10-3 mol/L-4.0+10-2 mol/L glucose is observed. The obtained biosensor exhibits high sensitivity, excellent reproductivity and good stability with substantially improved performance.Part two describes the manufacture and characterization of glucose oxidase -silver sol-polyvinyl butyral modified platinum electrodes with tris(2,2'-bipyridyl)cobalt(III) perchlorate as an electron transfer mediator in the glucose solution. The response of the glucose electrode is surveyed by determining cyclic voltammetric peak current values under aerobic solution conditions. Electrocatalytic oxidation of glucose at the electrode is evaluated with respect to temperature, pH value of solution and concentration of tris(2,2'-bipyridyl)cobalt(III) perchlorate. A linear response of the sensor in the wide range of 3.0+10-6 mol/L-1.1+10-4 glucose is observed. The obtained biosensor exhibits high sensitivity, excellent reproductivity and good stability with substantially improved performance.