Atomic-Thick PtNi Nanowires Assembled on Graphene for High-Sensitivity Extracellular Hydrogen Peroxide Sensors.

HO sensors with high sensitivity and selectivity are essential for monitoring the normal activities of cells. Inorganic catalytic nanomaterials show the obvious advantage in boosting the sensitivity of HO sensors; however, the HO detection limit of reported inorganic catalysts is still limited, which is not suitable for high-sensitivity detection of HO in real cells. Herein, novel atomic-thick PtNi nanowires (NWs) were synthesized and assembled on reduced graphene oxide (rGO) via an ultrasonic self-assembly method to attain PtNi NWs/rGO composite for boosting the electroanalysis of HO. In 0.05 M phosphate-buffered saline (pH 7.4) solution, the as-prepared PtNi NWs/rGO shows an extraordinary performance in quantifying HO in a wide range of concentrations from 1 nM to 5.3 mM. Significantly, the detection limit of PtNi NWs/rGO reaches unprecedented 0.3 nM at an applied potential of -0.6 V (vs Ag/AgCl), which enables the detection of traced amounts of HO released from Raw 264.7 cells. The excellent performance of HO detection on PtNi NWs/rGO is ascribed to the high-density active sites of atomic-thick PtNi NWs.