Cobalt Phosphide (Co2P) with Notable Electrocatalytic Activity Designed for Sensitive and Selective Enzymeless Bioanalysis of Hydrogen Peroxide

Abstract In this work, cobalt phosphide nanoparticles (Co2P NPs) were prepared by simple and mild hydrothermal method without the use of harmful phosphorous source. The morphological structure and surface component of Co2P were characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy measurements. Considering the excellent electrocatalytic reduction activity and good electrical conductivity of transition-metal phosphide, we fabricated Co2P NPs on indium tin oxide (ITO) substrate (Co2P/ITO) for H2O2 detection. The Co2P/ITO transducer displayed a rapid amperometric response less than 5 s, a broader response range from 0.001 to 10.0 mM and a low detection limit of 0.65 μM. In addition, the non-enzymatic Co2P/ITO sensor showed outstanding selectivity, reproducibility, repeatability and stability, all of which qualified the Co2P/ITO electrode for quite a reliable and promising biosensor for H2O2 sensing.