Novel nonenzymatic hydrogen peroxide sensor based on iron oxide–silver hybrid submicrospheres

Fe3O4–Ag hybrid submicrosphere was synthesized and developed as hydrogen peroxide sensor in this study. The hybrid sphere was fabricated via a two-step route, and proved by characterizations such as TEM, SEM, EDX, and XPS. Recent studies of hydrogen peroxide sensor based on silver nanoparticles inspired us to study the electrocatalytic property of the as-prepared submicrosphere. Though the Ag amount is quite little in the hybrid spheres, the electrochemical sensor constructed by the hybrid spheres exhibited fast, stable and well-defined electrocatalytic activity towards H2O2 reduction, which should be the contribution of the combination of Fe3O4 and Ag. The detection limit of H2O2 was also found to be 1.2 μM, which was lower than some enzyme-based biosensors.