An on–off biosensor based on multistimuli-responsive polymer films with a binary architecture and bioelectrocatalysis

Abstract

Abstract The films with binary architecture combining electropolymerized poly(4-vinylpyridine) (P4VP) as the inner layers and chemically polymerized poly(N,N′-diethylacrylamide) (PDEA) hydrogels containing glucose oxidase (GOD) as the outer layers were successfully prepared on electrode surface, designated as P4VP/PDEA-GOD. Cyclic voltammetric response of ferrocenedicarboxylic acid (Fc(COOH) 2 ) at P4VP/PDEA-GOD film electrodes showed reversible on–off behaviors to environmental pH, temperature, ClO 4 − , and SO 4 2− concentration. In particular, the films exhibited a very sensitive ClO 4 − -responsive behavior toward Fc(COOH) 2 with the critical concentration as low as 0.01 M. The responsive mechanism of the films to different stimuli was discussed and explored by comparative experiments. The pH- and ClO 4 − -sensitive properties were mainly attributed to the electrostatic interaction between P4VP inner layers and Fc(COOH) 2 under different conditions, and the thermo- and SO 4 2− -responsive behaviors should be ascribed to the structure change of PDEA hydrogels in PDEA-GOD outermost layers under different conditions. The multiple stimuli-responsive films could be further used to realize multiply switchable electrochemical oxidization of glucose catalyzed by GOD immobilized in the films with Fc(COOH) 2 in solution as the mediator. The films with the unique binary architecture may open a new way to establish a foundation for fabricating a novel type of multi-controllable biosensors based on bioelectrocatalysis with immobilized enzymes.