A non-enzymatic amperometric hydrogen peroxide sensor based on iron nanoparticles decorated reduced graphene oxide nanocomposite

A simple and facile green process was used for the synthesis of iron nanoparticles (FeNPs) decorated reduced graphene oxide (rGO) nanocomposite by using Ipomoea pes-tigridis leaf extract as a reducing and stabilizing agent. The as-prepared rGO/FeNPs nanocomposite was characterized by transmission electron microscopy, X-ray spectroscopy and Fourier transform infrared spectroscopy. The nanocomposite was further modified on the glassy carbon electrode and used for non-enzymatic sensing of hydrogen peroxide (H₂O₂). Cyclic voltammetry results reveal that rGO/FeNPs nanocomposite has excellent electro-reduction behavior to H₂O₂ when compared to the response of FeNPs and rGO modified electrodes. Furthermore, the nanocomposite modified electrode shows 9 and 6 folds enhanced reduction current response to H₂O₂ than that of rGO and FeNPs modified electrodes. Amperometric method was further used to quantify the H₂O₂ using rGO/FeNPs nanocomposite, and the response was linear over the concentration ranging from 0.1 μM to 2.15 mM. The detection limit and sensitivity of the sensor were estimated as 0.056 μM and 0.2085 μA μM⁻¹ cm⁻², respectively. The fabricated sensor also utilized for detection of H₂O₂ in the presence of potentially active interfering species, and found high selectivity towards H₂O₂.