▎ 摘　　要

Herein, we demonstrate the first use of a reduced graphene oxide (rGO)-organic dye nanoswitch for the label-free, sensitive and selective detection of Hg2+ using bifunctional rGO as an effective nanoquencher and highly selective nanosorbent. Moreover, a reversible on-off INHIBIT rGO logic gate based on a cysteine-Hg2+ system has also been designed.