Effect of quaternization of the glucose oxidase ''wiring'' redox polymer on the maximum current densities of glucose electrodes

Redox polymers based on the poly(vinylpyridine) complex of [Os(bpy)(2)Cl](+/2+) were quaternized with methyl iodide, and the quaternized polymers were used to ''wire'' glucose oxidase. Quaternization enhanced both the rate of electron transport in cross-linked redox hydrogels containing glucose oxidase and the strength of the electrostatic complex formed between the polycationic redox polymer and the polyanionic glucose oxidase. Quaternization with methyl groups also decreased the number of pyridine rings available for cross-linking by the water soluble cross-linker poly(ethylene glycol) diglycidyl ether. The current densities of glucose electrooxidation increased with the degree of quaternization of the ''wires'' until one-third of the pyridine rings were quaternized, and the activation energies decreased until one-half of the rings were quaternized.