Effect of Quaternization of the Glucose Oxidase “Wiring” Redox Polymer on the Maximum Current Densities of Glucose Electrodes

Abstract

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.

ELECTROCHEMICAL BIOSENSORS: RECOMMENDED DEFINITIONS AND CLASSIFICATION*

“…(b) Entrapment of biological receptors within a polymeric matrix, such as polyacrylonitrile, agar gel, Electrochemical biosensors: de®nitions and classi®cationpolyurethane (PU) or poly(vinyl) alcohol) (PVAL) membranes, sol gels or redox hydrogels with redox centres such as [Os(bpy) 2 Cl] /2 [27].…”

Construction of multicomponent catalytic films based on avidin-biotin technology for the electroenzymatic oxidation of molecular hydrogen

“…First, a free mediator can simply carry the electrons. Second, electrical contact between immobilized enzyme and electrode can be achieved using redox relays bound directly to the enzyme (Heller, 1990;Schuhmann et al, 1991) or to the polymer which incorporates the enzyme (Hale et al, 1991;Ohara et al, 1993;Ye et al, 1993;Rajagopalan et al, 1996;Hodak et al, 1997). For example, polymer-bound viologens have proved to be efficient redox mediators for immobilized reductases (Cosnier et al, 1994;Eng et al, 1994;De Lacey et al, 1995).…”

A Pyruvate Oxidase Electrode Based on an Electrochemically Deposited Redox Polymer

“…The sensitivity for pyruvate (0.2 A cm À2 mol À1 L) was several times higher than all previously reported values [3±5, 11] and comparable to the Heller-type glucose sensors based on redox hydrogels (ca. 1 A cm À2 mol À1 L [28]). In contrast to the latter``wired-enzyme'' electrodes the electrochemical deposition of the redox polymer implies the possibility to selectively modify discrete microelectrodes in arrays with high spatial resolution.…”