Ultrafine palladium nanoparticles grown on graphene nanosheets for enhanced electrochemical sensing of hydrogen peroxide

A nonenzymatic electrochemical method was developed for hydrogen peroxide (H2O2) detection using an electrode modified with palladium nanoparticles (PdNPs)-graphene nanosheets (PdNPGNs). Ultrafine PdNPs were homogeneously modified on graphene nanosheets through a facile spontaneous redox reaction and characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy technique. Based on the voltammetric and amperometric results, the PdNPGNs-modified glassy carbon electrode (PdNPGNs-GCE) demonstrated direct and mediatorless responses to H2O2 at a low potential. The analytical performances of the PdNPGNs-GCE toward H2O2 reduction was evaluated in the linear response range from 0.1 μM to 1.0 mM, with a detection limit (S/N = 3) of 0.05 μM. The PdNPGNs-GCE showed excellent resistance toward poisoning from such interfering species as ascorbic acid, dopamine and glucose. Furthermore, the electrochemical sensor presented good characteristics in terms of stability and reproducibility, promising the applicability of this sensor in practical analysis.