Synthesis of Ag-Au/Reduced Graphene Oxide/TiO2 Nanocomposites: Application as a Non-enzymatic Amperometric H2O2 Sensor

Background: Owing to the strong oxidizing and reducing properties of hydrogen peroxide (H2O2), it has been widely used in many fields. In particular, H2O2 is widely used in the aseptic packaging of drinks and milk. The residue of H2O2 in food is harmful to human health. Therefore, the quantitative detection of H2O2 is of great practical significance. Methods: The Ag-Au/RGO/TiO2 nanocomposites were facilely synthesized by photo-reduction approach. Transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy were used to characterize the synthesized Ag-Au/RGO/TiO2 nanocomposites. Cyclic voltammetry was used to analyze the electrochemical behavior of H2O2 on the Ag-Au/RGO/TiO2/GCE. Amperometry was applied for quantitative determination of the concentration of H2O2. Results: A novel Ag-Au/RGO/TiO2/GCE was prepared. The Ag-Au/RGO/TiO2/GCE displayed high electrocatalytic activity towards H2O2 reduction. An electrochemical reduction peak of H2O2 was achieved on the Ag-Au/RGO/TiO2/GCE. The current responses were linear with the concentrations of H2O2 in the range of 0.01-30 mM with the detection limit of 3.0 μM (S/N = 3). Conclusion: An amperometric sensor has been prepared for H2O2 detection using Ag- Au/RGO/TiO2/GCE. The Ag-Au/RGO/TiO2/GCE shows good performance for the determination of H2O2. The proposed sensor exhibits good selectivity and stability.