POLYPYRROLE GLUCOSE OXIDASE ELECTRODES: SUPPRESSION OF COOXIDIZABLE SUBSTANCES

Abstract

With a polypyrrole glucose oxidase electrode, the analyte glucose can be determined by the anodic oxidation of the enzymatically produced hydrogen peroxide (H202). Attne high potential (650 mV vs. Ag/AgCl) necessary for the detection of H20O2 other cooxidizable substances present in the sample can interfere, resulting in a signal for glucose, that is too high. In order to suppress the interference, we studied the molecular "sieve effect" (1,2,3) of the polypyrrole immobilization matrix on a platinum substrate (d=imm). Twodifferent types of enzymeelectrodes were used (Fig.1).