Poly(N-isopropylacrylamide) (PNIPAM) hydrogel films containing glucose oxidase (GOD), designated as PNIPAM-GOD, were synthesized on the surface of pyrolytic graphite (PG) electrodes through radical cross-linking polymerization method. Cyclic voltammetric (CV) response of ferrocenecarboxylic acid (Fc(COOH)) at PNIPAM-GOD film electrodes was very sensitive to the environmental temperature, sulfate concentration, and addition of methanol solvent. For example, at 25 degrees C, Fc(COOH) exhibited a quasi-reversible CV peak pair with large peak currents in pH 7.0 aqueous solutions containing no sulfate for the films; while at 37 degrees C, the CV response was greatly suppressed. By switching the film electrodes in solutions between 25 and 37 degrees C, the CV peak currents of Fc(COOH) cycled between a quite large value and a very small one, showing the reversible thermo-sensitive switching property between the on and off states. Similarly, the reversible SO42-- and methanol-sensitive on-off behavior of the films toward the probe was also observed. This triply responsive property could be used to realize the thermo-, SO42--, and methanol-controlled electrochemical oxidation of glucose catalyzed by GOD immobilized in the films and mediated by Fc(COOH) in solution. This "smart" interface may establish a foundation for fabricating a novel type of multi-controllable biosensors based on bioelectrocatalysis. (C) 2011 Elsevier Ltd. All rights reserved.