Decoration of GO with Fe spinel-Naf/DMAP: an electrochemical probe for sensing H2O2 reduction

Abstract

We herein report the preparation of graphene oxide decorated with Fe spinel (Fe₃O₄)-Naf/DMAP for an unprecedented and highly selective non-enzymatic electrochemical sensing of hydrogen peroxide reduction. The linking of 3,7-bis (dimethylamino)-phenothiazin-5-ium chloride (DMAP) to the graphene oxide occurred via electrostatic interactions of the cationic organic compound with negatively charged oxygen-containing groups (–COO⁻ and –O⁻) available on the edges of the graphene oxide. Fe₃O₄ (Fe²⁺, Fe³⁺) nanoparticles were adhered further on SO₃⁻ moieties of the Nafion coated over the DMAP-GO/GCE through electrostatic interactions. This green approach was used to prepare a derived graphene oxide hybrid nano-material. This material was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV-visible spectroscopy, X-ray diffraction (XRD), and cyclic voltammetry (CV). The prepared material was utilized to detect H₂O₂ subjected to electrocatalytic reduction and to determine its concentration in the linear range of 5.5 μM to 2.4 mM. Nafion was employed as a dispersion medium, and an anchor for Fe₃O₄ to make the composite and to prevent interfering effects of other metabolites. The detection limit of this highly selective and highly reproducible film was estimated to be 0.6 μM with a sensitivity of 32.0 μA mM⁻¹ cm⁻².