Chronocoulometric interrogations of oxidase‐based enzyme electrodes for enhanced selectivity

Abstract

ReceiL ed ' Voz mbei 25 1992 Jr P. Ward ABSTRACT Classical oxidase-based enzyme electrodes rely on the aniperometric determination of H102. Such electrodes are vulnerable to electroactive interferants found in biological solutions. Some interferants ma)-be oxidized at anodic potentials, necessitating the use of permselective barrier membranes. Two generic chronocoulometric approaches to the interrogation of oxidase-based enzyme electrodes have been developed. Both the chronocoulometric interrogation of H20, and the chronocoulometric interrogation of the reduction of 0, (formed from the anodic oxidation of H,02) have allowed new correlations 10 be made with 0 to 20 mM glucose concentrations. Furthermore. the interrogation of 0, has allowed a glucose sensor to be constructed that is virtuall!. free from the effects of electroactive interferants.