High sensitive and selective sensing of hydrogen peroxide released from pheochromocytoma cells based on Pt-Au bimetallic nanoparticles electrodeposited on reduced graphene sheets.

In this study, a high sensitive and selective hydrogen peroxide (H2O2) sensor was successfully constructed with Pt-Au bimetallic nanoparticles (Pt-Au NPs)/reduced graphene sheets (rGSs) hybrid films. Various molar ratios of Au to Pt and different electrodeposition conditions were evaluated to control the morphology and electrocatalytic activity of the Pt-Au bimetallic nanoparticles. Upon optimal conditions, wide linear ranges from 1 µM to 1.78 mM and 1.78 mM to 16.8 mM were obtained, with a detection limit as low as 0.31 µM. Besides, due to the synergetic effects of the bimetallic NPs and rGSs, the amperometric H2O2 sensor could operate at a low potential of 0 V. Under this potential, not only common anodic interferences induced from ascorbic acid, uric acid and dopamine, but also the cathodic interference induced from endogenous O2 could be effectively avoided. Furthermore, with rat pheochromocytoma cells (PC 12) as model, the proposed sensor had been successfully used in the detection of H2O2 released from the cancer cells. This method with wide linear ranges and excellent selectivity can provide a promising alternative for H2O2 monitoring in vivo in the fields of physiology, pathology and diagnosis.