A Two-step Electrodeposition of Pd-Cu/Cu2O Nanocomposite on FTO Substrate for Non-enzymatic Hydrogen Peroxide Sensor

Background: Hydrogen peroxide (H 2 O 2 ) is a common reagent in the production and living, but excessive H 2 O 2 may enhance the danger to the human body. Consequently, it is very important to develop economical, fast and accurate techniques for detecting H 2 O 2 . Methods: A simple two-step electrodeposition process was applied to synthesize Pd-Cu/Cu 2 O nanocomposite for non-enzymatic H 2 O 2 sensor. Cu/Cu 2 O nanomaterial was firstly electrodeposited on FTO by potential oscillation technique, and then Pd nanoparticles were electrodeposited on Cu/Cu 2 O nanomaterial by cyclic voltammetry. The chemical structure, component, and morphology of the synthesized Pd-Cu/Cu 2 O nanocomposite were characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical properties of Pd-Cu/Cu 2 O nanocomposite were studied by cyclic voltammetry and amperometry. Results: Under optimal conditions, the as-fabricated sensor displayed a broad linear range (5-4000 μM) and low detection limit (1.8 μM) for the determination of H 2 O 2 . The proposed sensor showed good selectivity and reproducibility. Meanwhile, the proposed sensor has been successfully applied to detect H 2 O 2 in milk. Conclusion: The Pd-Cu/Cu 2 O/FTO biosensor exhibits excellent electrochemical activity for H 2 O 2 reduction, which has great potential application in the field of food safety.