Gold-cerium oxide (Au/CeO2) composite was synthesized by a deposition-precipitation method and used to fabricate a highly sensitive non-enzymatic electrochemical sensor for hydrogen peroxide (H2O2) detection. The morphology and microstructure of the Au/CeO2 composite was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). UV-Vis spectroscopy showed a strong plasmonic absorbance (in the range of 500-650 nm) due to Au nanoparticles deposited onto the surface of ceria. Sensing tests carried out by cyclic voltammetry (CV) showed that the Au/CeO2-composite-modified screen-printed carbon electrode exhibited electrocatalytic response to H2O2. By chronoamperometry, a detection limit (S/N=3) as low as 5 µM and a sensitivity of 27.1 µA mM-1cm-2 were measured. These results open the route for a potential use of the fabricated Au/CeO2-based sensor to improve the H2O2 detection ability in many industrial fields.
