Achieving direct electrochemistry of glucose oxidase by one step electrochemical reduction of graphene oxide and its use in glucose sensing

•A direct electron transfer reaction of glucose oxidase was observed on GCE/ERGO/SDS.•This composite film was successfully applied in preparation of glucose biosensor.•The detection limit of the biosensor was estimated to be 40.8 μM.•The results from the sensor were similar to those obtained from the clinical analyzer.

In this paper, the direct electrochemistry of glucose oxidase (GOD) was accomplished at a glassy carbon electrode modified with electrochemically reduced graphene oxide/sodium dodecyl sulfate (GCE/ERGO/SDS). A pair of reversible peaks is exhibited on GCE/ERGO/SDS/GOD by cyclic voltammetry. The peak-to-peak potential separation of immobilized GOD is 28 mV in 0.1 M phosphate buffer solution (pH 7.0) with a scan rate of 50 mV/s. The average surface coverage is 2.62 × 10− 10 mol cm− 2. The resulting biosensor exhibited a good response to glucose with linear range from 1 to 8 mM (R2 = 0.9878), good reproducibility and detection limit of 40.8 μM. The results from the biosensor were similar (± 5%) to those obtained from the clinical analyzer.