Graphene frameworks-confined synthesis of 2D-layered NiCoP for the electrochemical sensing of H2O2 at lower overpotential

A new 2D-layered nickel cobalt phosphide nanosheet confined by 3D graphene frameworks (denoted as NiCoP/GFs) is in situ controllably synthesized as a highly efficient and durable electrocatalyst, which is obtained from the transformation of corresponding NiCo layer double hydroxides and GFs. Hydrogen peroxide (H2O2) is selected as a demonstration to study the electrochemical sensing performance of the NiCoP/GFs. Benefiting from 2D morphology of NiCoP and network structure of GFs, NiCoP/GFs exhibits remarkable electroactivity toward H2O2 at a relatively low overpotential of approximately - 0.3 V (vs sat. Ag/AgCl) in 0.01 M phosphate-buffered saline solution (PBS, pH = 7.4). The NiCoP/GFs-based H2O2 electrochemical sensor achieves a high sensitivity of similar to 4398 mu A mM(-1) cm(-2), a low detection limit of 0.028 +/- 0.006 mu M, and desirable selectivity. In addition, the sensor can sensitively detect H2O2 from living cancer cells. This study not merely broadens the synthesis methods of transition metal phosphide-based nanocrystals but the NiCoP/GFs also has broad prospects in diverse electrochemistry fields.

Automated summary

A highly efficient and durable 2D-layered nickel cobalt phosphide nanosheet, confined by 3D graphene frameworks, exhibits remarkable electroactivity towards hydrogen peroxide and has broad prospects in the field of electrochemistry, especially in biosensing applications.