▎ 摘　　要

Nano-impact chronoamperometric experiments are a powerful technique for simultaneously probing both the potential of zero charge (PZC) and the diffusion coefficient (D-0) of graphene nanoplatelets (GNPs). The method provides an efficient general approach to material characterisation. Using nano-impact experiments, capacitative impacts can be seen for graphene nanoplatelets of 15 mu m width and 6-8 nm thickness. The current transient features seen allow the determination of the PZC of the graphene nanoplatelet in PBS buffer as -0.14 +/- 0.03 V (vs. saturated calomel electrode). The diffusion coefficient in the same aqueous medium, isotonic with many biological conditions, for the graphene nanoplatelets is experimentally found to be 2 +/- 0.8 x 10(-13) m(2) s(-1). This quick characterisation technique may significantly assist the application of graphene nanoplatelets, or similar nano-materials, in electronic, sensor, and clinical medicinal technologies.