A simple electrochemical approach to fabricate a glucose biosensor based on graphene–glucose oxidase biocomposite

We report a simple electrochemical approach for the immobilization of glucose oxidase (GOx) on reduced graphene oxide (RGO). The immobilization of GOx was achieved in a single step without any cross linking agents or modifiers. A simple solution phase approach was used to prepare exfoliated graphene oxide (GO), followed by electrochemical reduction to get RGO–GOx biocomposite. The direct electrochemistry of GOx was revealed at the RGO–GOx modified glassy carbon electrode (GCE). The electrocatalytic and electroanalytical applications of the proposed film were studied by cyclic voltammetry (CV) and amperometry. It is notable that the glucose determination has been achieved in mediator-free conditions. RGO–GOx film showed very good stability, reproducibility and high selectivity. The developed biosensor exhibits excellent catalytic activity towards glucose over a wide linear range of 0.1–27 mM with a sensitivity of 1.85 μA mM−1 cm−2. The facile and easy electrochemical approach used for the preparation of RGO–GOx may open up new horizons in the production of cost-effective biosensors and biofuel cells.

► Reduced graphene oxide–glucose oxidase biocomposite (RGO–GOx) prepared. ► One step, green electrochemical approach for RGO–GOx preparation. ► Crosslinking agents, modifiers, or mediators were not used. ► RGO–GOx was employed for glucose determination. ► High selectivity, good stability, wide linear range and biocompatibility.