Polypyrrole-based enzyme electrode with immobilized glucose oxidase for electrochemical determination of glucose

Abstract

Polypyrrole enzyme electrode was formed by immobilization of glucose oxidase via glutaraldehyde into electrochemically synthesized polypyrrole on glassy carbon electrode. Electrochemical synthesis was performed in 0.5 mol dm-3 HCl and 0.2 mol dm-3 pyrrole at constant current density of 2 mA cm-2. Chronopotentiometric curves of polypyrrole enzyme electrode were recorded at current density of 42 nA cm-2 for different glucose concentrations. The determined value of the apparent Michaelis-Menten constant was 0.045 mmol dm-3 which is significantly lower than that of free enzyme indicating enhanced enzyme efficiency when it is immobilized into electroconducting polymer matrix.