Efficiency improvement in non-enzymatic H2O2 detection induced by the simultaneous synthesis of Au and Ag nanoparticles in an RGO/Au/Fe3O4/Ag nanocomposite

Abstract

Developing a quick and precise technique for hydrogen peroxide (H₂O₂) detection would open up a new class of technologies for biological, medical and chemical applications. Herein, using a polyol method, we report the synthesis of a reduced graphene oxide (RGO)/Au/Fe₃O₄/Ag nanocomposite with high electrocatalytic efficiency, involving a modified glassy carbon electrode for non-enzymatic trace analysis of H₂O₂. The resulting nanocomposite showed an inherently high specific surface area and fast electron transfer characteristics of graphene, and Au, Fe₃O₄ and Ag nanoparticles (NPs). With a detection limit of 1.43 μM at a signal-to-noise ratio of 3 and a response time of 2 s, H₂O₂ concentrations ranging from 2 μM to 12 mM can be detected by the nanocomposite sensor. By investigating non-enzymatic H₂O₂ detection in the presence of other biomaterials including ascorbic acid, uric acid, glucose and sucrose, the selectivity of the sensor was evaluated. Furthermore, we test our nanocomposite sensor for practical applications in detection of H₂O₂, indicating good recoveries for a hair dye cream as a pharmaceutical sample. Our results on the electrocatalytic efficiency of the RGO/Au/Fe₃O₄/Ag nanocomposite were compared with those of the RGO/Fe₃O₄ nanocomposite, revealing the role of Au and Ag NPs in the sensing performance improvement.