A novel hydrogen peroxide sensor based on electrodeposited copper/cuprous oxide nanocomposites

In this work, copper/cuprous oxide (Cu/Cu2O) nanocomposites were electrodeposited on a fluorine doped tin oxide (FTO) glass substrate for sensitive determination of hydrogen peroxide (H2O2). The Cu/Cu2O nanocomposites were synthesized on FTO at a constant current density of -0.4 mA cm-2 in 0.3 M CuSO4 (pH 9.5) under magnetic agitation. The composition and morphology of Cu/Cu2O nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy and X-ray photoelectron spectroscopy. Taking advantage of the synergistic effects of Cu and Cu2O, the fabricated Cu/Cu2O/FTO electrode showed excellent electrocatalytic activity towards the oxidation of H2O2. The electrocatalytic performance of Cu/Cu2O/FTO was evaluated by linear sweep voltammetry and amperometry. Under optimized conditions, the developed sensor exhibited a wide linear range of 0.2-2000 μM for the determination of H2O2 with a detection limit of 0.04 μM (S/N = 3). In addition, the proposed H2O2 sensor was successfully applied for the determination of H2O2 in milk samples, indicating that the electrodeposited Cu/Cu2O nanocomposites are promising nanomaterials for electrochemical sensors.