Electrical Communication between Graphite Electrodes and Glucose Oxidase/RedoxPolymer Complexes

摘要

Redox polymers can fold along the glycoproteins of glucose oxidase (M W 160,000)at low electrolyte concentrations and thereby penetrate the enzyme. Upon penetration, the distance between the redox centers of the polymer and the FADH2 centers of the reduced enzyme is reduced sufficiently for electrons to be transferred and, therefore, for the mediated electro-oxidation of glucose on conventional electrodes. At high (1M) electrolyte (NuCl) concentrations the redox polymers coil. Such coiling prevents the penetration of the enzyme by the redox polymers. Consequently, electron transfer does not take place and glucose is not electro-oxidized. When an appropriate polycationic redox polymer is covalently bound to the enzyme, the electro-oxidation of glucose occurs even at high electrolyte concentrations. Electron transfer from the enzyme's FADH2 centers to copolymers of poly(N-methyl-4-vinlypyridinium) chloride with either poly(vinylferroccne), E = 0.25V (SCE), or with poly(4-vinlypyridine) complexes of Os(bpy)2Cl, E = 0.25V (SCE), or of Os(4,4-dimethylbpy)2Cl, E = 0.15V (SCE) is rapid. Keywords: Reprints (js)