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

In this work, cobalt phosphide nanoparticles (Co 2 P NPs) were prepared by simple and mild hydrothermal method without the use of harmful phosphorous source. The morphological structure and surface component of Co 2 P 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 Co 2 P NPs on indium tin oxide (ITO) substrate (Co 2 P/ITO) for H 2 O 2 detection. The Co 2 P/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 Co 2 P/ITO sensor showed outstanding selectivity, reproducibility, repeatability and stability, all of which qualified the Co 2 P/ITO electrode for quite a reliable and promising biosensor for H 2 O 2 sensing.