Multi-Switchable Bioelectrocatalysis Based on Semi-Interpenetrating Polymer Network Films Prepared by Enzyme-Induced Polymerization

Abstract

The polymerization of N,N′-diethylacrylamide (DEA) into PDEA hydrogels could be initiated by glucose oxidase (GOD) in the presence of glucose, Fe2+ and oxygen. Based on this, the semi-interpenetrating polymer network (semi-IPN) films containing PDEA, hyaluronic acid (HA) and GOD were prepared on electrode surface. The electroactive probe ferrocenedicarboxylic acid (Fc(COOH)2) in solution demonstrated reversible pH-, temperature- and SO42−-sensitive cyclic voltammetric (CV) on-off behavior at the film electrodes. Taking pH-responsive property of the system as an example, at pH 4.5, the probe showed a large and well-defined CV peak pair, and the system was at the on state; while at pH 8.0, the CV peaks were greatly suppressed and the system was at the off state. The system could be further used to switch the electrochemical oxidation of glucose catalyzed by GOD in the films and mediated by Fc(COOH)2 in solution with pH, temperature and SO42− as the stimuli. Herein the enzyme GOD functioned in two ways: (1) in preparation of the films, GOD could induce radical polymerization of PDEA; (2) in the following electrochemical studies, GOD could catalyze the oxidation of glucose and helped to realize the switchable bioelectrocatalysis with amplification effect.