Facile synthesis of novel CuO/Cu₂O nanosheets on copper foil for high sensitive nonenzymatic glucose biosensor

Design and synthesis of binder-free electrodes with active nanomaterials on the surface are expected to enhance electrochemical properties. In the work, a novel thin film formed by assembled CuO nanosheets and ultra-thin Cu₂O film directly adhered on copper foil was obtained by just simply oxidizing the Cu foil using H₂O₂. The obtained product on Cu foil consists of a film assembled by CuO/Cu₂O nanosheets. The ultrathin CuO nanosheets with large surface area provide adequate active sites for the electrocatalysis and the strong binding will promote the electron transfer between active nanomaterials and Cu substrate. The electrochemical performance shows that this novel structure as an electrode exhibits excellent properties for the non-enzyme glucose sensor, with an ultrahigh sensitivity of 1.541 mA mM⁻¹ cm⁻², a low detection limit of 0.57 μM and the linear range is up to 4 mM. Good stability and high selectivity were also obtained by using CuO/Cu₂O nanosheets@Cu as a nonenzymatic glucose sensor, and furthermore, the electrode shows powerful reliability for analyzing human serum samples. Therefore, the CuO/Cu₂O film based on Cu foil binder-free electrode may become a promising nonenzymatic glucose sensor and the work also provides a strategy for the design of electrochemical electrode.