A facile route for constructing a graphene-chitosan-ZrO2 composite for direct electron transfer and glucose sensing

Integrating graphene-based composites with enzymes provides a potent strategy to enhance biosensor performance due to their unique physicochemical properties. Herein we report on the utilization of graphene-chitosan-ZrO2 (ER-GO/CS/ZrO2) composite as an immobilization matrix for glucose oxidase (GOD). In comparison with electrodes modified with the component materials individually, the ER-GO/CS/ZrO2 modified electrode exhibited excellent electron transfer properties for GOD with a rate constant of 3.12 s(-1). The obtained glucose biosensor displayed satisfactory performance over an acceptable linear range from 0.2 mM to 1.6 mM with a detection limit of 45.6 mu M at -0.4 V and a sensitivity of 7.6 mu A mM(-1) cm(-2). The integration of graphene, chitosan and mesoporous materials can not only be used for immobilizing GOD, but can also be extended to other enzymes and bioactive molecules, thus providing a promising platform for the development of biosensors.