Fabrication of a novel disposable glucose biosensor using an electrochemically reduced graphene oxide-glucose oxidase biocomposite

摘要

A disposable glucose biosensor has been fabricated on the surface of a cost-effective pencil graphite electrode (PGE) by an electrochemical method, using glucose oxidase (GOx) and reduced graphene oxide (rGO). Electrochemical pre-treatment of the PGE enables the adsorption of the rGO-GOx biocomposite. The biocomposites of GOx and rGO were simply prepared by the electrochemical potential cycling method. Efficient immobilization of rGO-GOx is confirmed by field emission scanning electron microscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and cyclic voltammetry measurements. The rGO nanosheets enhance direct electron transfer (DET) between GOx and the electrode surface. Determination of glucose indirectly by O-2 reduction was achieved, which showed high sensitivity, selectivity, reproducibility and stability without a redox mediator. The sensor exhibits a linear current response for a wide range of glucose concentrations between 1.0 x 10(-5) and 1.0 x 10(-3) M (R = 0.998), and a dynamic range up to 10.0 x 10(-3) M with a detection limit of 5.8 mu M. The rGO-GOx biosensor showed an excellent anti-interference ability against electroactive species and proved to be useful for the determination of glucose in human serum samples.