Electrochemical Determination of Hydrogen Peroxide by a Nonenzymatic Catalytically Enhanced Silver-Iron (III) Oxide/Polyoxometalate/Reduced Graphene Oxide Modified Glassy Carbon Electrode

Abstract

The synergism of phosphomolybdic acid hydrate (POM) decorated with silver-iron (III) oxide (Ag-Fe₂O₃) nanoparticles and anchored on reduced graphene oxide (RGO) have been demonstrated to be effective as a nonenzymatic H₂O₂ sensor platform. The assembly of the sensor components and their interactions were probed morphologically, spectroscopically and electrochemically. The Ag-Fe₂O₃/POM/RGO nanocomposite sensor provided an enhanced electroactive surface area, electrical conductivity and sensitivity for hydrogen peroxide compared to an unmodified glassy carbon electrode (GCE) at –0.55 V versus a saturated calomel electrode. The developed sensor amperometric response was linear across the concentration range from 0.3 mM to 3.3 mM (R² = 0.992) with a detection limit and sensitivity of 0.2 μM and 271 μA·mM^‒1·cm⁻² respectively. Concomitantly, a short response time of T90 2O₃ stimulated by its adhesion to the distinctive POM/RGO matrix.