A facile and simple fabrication of CuO nanosheets on copper foil as a nanoelectrode for a H2O2 sensing application is proposed. On immersing a copper foil into NaOH aqueous solution (0.1 M) for 48 h, CuO nanosheets were spontaneously formed at room temperature. The sheet-like morphology of thickness several tens of nanometers and width similar to 500 nm was observed with a SEM. The monoclinic phase of a CuO nanosheet was confirmed with microstructural analyses of XRD and Raman spectra. The directly grown CuO nanosheet is mechanically stable and offers an excellent electrochemical sensing platform. The CuO nanosheet electrode shows excellent electrocatalytic response to H2O2 with a significantly small overpotential for its oxidation and reduction. A CuO nanosheet also exhibits a rapid response and great sensitivity for an amperometric detection of H2O2. The novel spontaneously grown CuO nanosheet electrode is readily applicable to other analytes and has great prospective applications for electrochemical detection. (C) 2015 Elsevier B.V. All rights reserved.