Nonenzymatic amperometric sensing of glucose using a glassy carbon electrode modified with a nanocomposite consisting of reduced graphene oxide decorated with Cu₂O nanoclusters

We describe a simple solvothermal method for preparation of reduced graphene oxide nanosheets decorated with uniform Cu₂O nanoclusters by using poly(vinyl pyrrolidone)-poly(methacrylamide)-poly(vinyl imidazole) triblock co-polymer as a shape-directing agent and L-glutamic acid as a reducing agent. The resulting nanocomposite was deposited on a glassy carbon electrode where it displays improved electrocatalytic activity toward glucose oxidation in 0.5 M NaOH. This observation was exploited to construct a non-enzymatic amperometric sensor for glucose. It has a detection limit as low as 1.0 μM, high sensitivity (23.058 μA mM⁻¹), and a dynamic (analytical) range that extends from 5.0 to 9595 μM at a working potential of 600 mV (vs. SCE). (author)