In this article, Cu2O/Cu NC nanocomposite catalysts on glass carbon electrodes have been synthesized by electrochemical deposition at −0.2 V versus silver/silver chloride and used to construct an electrochemical sensor for detection of hydrogen peroxide. The effects of deposition time and pH were investigated in detail. In 0.1 M phosphate buffer saline (PBS, pH = 6.5), the Cu2O/Cu NC modified electrode exhibits a wide linear dependence (R = 0.996) at a concentration of H2O2 from 4.0 × 10−7 M to 1.0 × 10−2 M, a high sensitivity of 870.4 μA mM−1 cm−2 and a detection limit of 2.0 × 10−7 M. Additionally, the sensor was applied for the determination of H2O2 in milk, showing its potential for practical applications.
