In situ synthesis of carbon-encapsulated Ni nanoparticles decorated graphene nanosheets with high reactivity toward glucose oxidation and sensing

Using graphene oxides (GO) as carbon source and NaCl crystals as the solid dispersant, a three-dimensional carbon-based nanohybrid was prepared by anchoring carbon shells-encapsulated Ni nanoparticles onto the reduced graphene oxides nanosheets (Ni@C@rGO). The as-obtained Ni@C@rGO exhibits larger specific surface area and pore volume as well as higher reactivity toward glucose oxidation, compared with the prepared Ni@rGO by the same conditions without NaCl crystals. The higher electrochemical reactivity may be originated from the ultrathin carbon shells, high dispersion of active Ni nanoparticles, and high conductivity of the graphene substrates. To further explore its electrochemical applications, Ni@C@rGO was employed to construct a glucose sensing platform, offering a low detection limit (0.34 μM) and wide linear range (2–951 μM). It was successfully utilized to monitor the glucose level in human serums, and satisfactory results were obtained. This used preparation strategy is in favor of making more nanocomposites with superior electrochemical properties.