Electrochemical hydrogen peroxide sensor based on a glassy carbon electrode modified with nanosheets of copper-doped copper(II) oxide

A new electrochemical sensor for H2O2 was constructed by depositing copper doped CuO nanosheets on a glassy carbon electrode (GCE). The morphology and composition of the modified electrode were characterized via scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. The electrochemical properties of the electrode were studied using cyclic voltammetry and electrochemical impedance spectroscopy. The catalytic performance of the sensor was studied in 100 mM NaOH solution via differential pulse voltammetry and revealed the sensor to display significantly improved electrocatalytic activity with respect to the analysis of the H2O2 in comparison to a plain GCE or a GCE modified with copper only. The response to H2O2 at a working voltage of −0.46 V (vs. Ag/AgCl) is linear in the 0.003 – 8 mM concentration range, and the detection limit is 0.21 mM (at an S/N ratio of 3). Satisfactory results were obtained in the analysis of tap, rain and river waters spiked with H2O2. The analytical performance of this electrode compares favorably to the results obtained with other commonly used techniques for analysis of H2O2.