▎ 摘　　要

A simple and economical approach to produce graphene nanosheets (GNSs) in quantity based on the thermal expansion of graphite oxide (GO) powder has been developed, and the as-prepared GNS was further used for the detection of different trace heavy metal ions including Cu2+, Pb2+, and Cd2+. The few-layer GNSs with defects and residual -OH groups were shown to be particularly well suited for the determination of metal ions in the liquid phase using an electrochemical method, in which a remarkably low detection limit of 10(-11) mol/L for Pb2+ was achieved. The high-yield production technique of GNSs combined with the high sensitivity for the detection of metal ions could promote the development of the industrial manufacture of graphene-based nanosensors.