Nonenzymatic amperometric determination of hydrogen peroxide by graphene and gold nanorods nanocomposite modified electrode

Graphene-based electrochemical sensors have recently received much attention due to their outstanding sensing capability and economic viability. In this study, a novel non-enzymatic hydrogen peroxide (H2O2) sensor was developed using graphene and gold nanorods (GR-AuNRs) composite modified glassy carbon electrode (GCE). AuNRs were synthesized by seed-mediated growth method, and characterized by ultraviolet–visible spectroscopy (UV–vis) and transmission electron microscope (TEM). The GR-AuNRs composite material is endowed with a large electrochemical surface area and fast electron transfer properties in redox species. A GR-AuNRs composite modified electrode exhibits good performance in terms of the electrocatalytic reduction of H2O2; a sensor constructed from such an electrode shows a good linear dependence on H2O2 concentration in the range of 30 μM to 5 mM with a sensitivity of 389.2 μA mM−1 cm−2. The detection limit is estimated to be 10 μM. Furthermore, the GR-AuNRs modified electrode exhibits freedom of interference from other co-existing electroactive species. This study provides a new kind of nanocomposite modified electrode for electrochemical sensors.