Seed-Mediated Growth Method for Epitaxial Array of CuO Nanowires on Surface of Cu Nanostructures and Its Application as a Glucose Sensor

The preparation and characterization of a large-scale epitaxial array of single-crystalline CuO nanowires (NWs) on the surface of a Cu nanostructure (Cu−CuO nanocomposite) by a simple liquid−solid growth process at room temperature is demonstrated. The field-emission scanning electron microscopy image analysis indicated that the NWs are 50−80 nm wide at the root and 300−400 nm long. The high-resolution transmission electron microscopy study on individual CuO NWs revealed that the NWs are single crystalline with a growth orientation of [110]. X-ray powder diffraction and energy dispersive X-ray analysis of the samples revealed that the CuO NWs only cover the surface of dendritic Cu and that Cu dendrites still exist in the center of the Cu−CuO nanocomposite. Electrochemical impendance spectroscopy and cyclic voltammetry showed that the Cu−CuO nanocomposite has a stronger ability to promote electron transfer than the CuO NWs or CuO nanoparticles individually. The Cu−CuO nanocomposite was successfully used to modify a glassy carbon electrode to detect H2O2 and glucose with chronoamperometry. The result shows that the Cu−CuO nanocomposite may be of great potential as H2O2 and glucose electrochemical sensors.