Facile synthesis of hetero-nanostructured cuprous oxide-gold composite material for sensitive enzymeless glucose detection

A facile in situ preparation of Au NPs decorated Cu2O nanocomposite materials (Cu2O-Au NCMs) and its application in nonenzymatic electrochemical detection of glucose are reported. The combination of sodium hydroxide and ascorbic acid were used to prepare the Cu2O-Au NCMs at room temperature. The Cu(I) oxidation state was confirmed from the characteristic XPS peaks observed at 932.5 and 952.7 eV for Cu 2p3/2 and Cu 2p1/2, respectively. TEM images showed the formation of small sized (∼20 nm) Cu2O-Au NCMs and FESEM-EDX analysis revealed the uniform distribution of elements in the composite materials. The Au NPs and Cu2O exhibited synergistic electrocatalytic activity towards glucose oxidation in the absence of immobilized enzyme at the modified electrode. The GC/Cu2O-Au(3) modified electrode enormously shifted the over potential of glucose oxidation towards less positive potential when compared to the other electrodes. The amperometric sensor consisting of Cu2O-Au(3) NCMs showed the best experimental and estimated detection limits for glucose as 5.0 and 0.76 μM, respectively. The sensor showed a linear range from 5 μM to 2.385 mM glucose with a sensitivity of 1.63 μA μM−1 cm−2. The GC/Cu2O-Au modified electrode was also successfully applied for the sensitive and selective determination of glucose. •Hetero-nanostructured Cu2O-Au NCMs were prepared by a facile in situ simultaneous chemical reduction method.•The heterogeneous nucleation and growth of Au and Cu precursors to form tiny Cu2O-Au NCMs.•The binary Cu2Cu2O-Au NCMs sizes were 10 times smaller than the pristine Cu2O NPs.•The GC/Cu2O-Au electrode exhibited excellent sensitive and selective nonenzymatic electrochemical detection of glucose.