Novel determination of hydrogen peroxide by electrochemically reduced graphene oxide grafted with aminothiophenol–Pd nanoparticles

Graphene oxide (GO) has functionalized with aminothiophenol (ATP) and covalently bonded to the palladium (Pd) nanoparticles (NPs) via sulfur atom. The GO–ATP–Pd was electrochemically reduced to graphene oxide (ERGO) at a potential range of 0 to −1.5 V, and was used in electrochemical biosensing for hydrogen peroxide (H2O2). The ERGO–ATP–Pd-modified electrode showed the advantages of excellent electrocatalytic activity toward H2O2 in PBS solution. The ERGO–ATP–Pd was characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS) and electrochemical impedance spectroscopy (EIS). Cyclic voltammetry (CV) and chronoamperometry (CA) were used to characterize the performance of the biosensor. The proposed H2O2 biosensor exhibited a wide linear range from 0.1 μM to 10 mM, and a low detection limit of 0.016 μM (S/N = 3), with a fast response time of less than 10 s. The biosensor, therefore, demonstrated excellent capability for the analysis of H2O2.