▎ 摘　　要

In this paper, we demonstrated a highly discriminated and reliable molecular switch based on the interaction between the self-duplex of (Py)A-substituted oligodeoxyadenylate and graphene oxide in aqueous solution. This system showed a clear on/off state through the association and dissociation of (Py)A-modified oligodeoxynucleotide with graphene oxide in manipulated pH conditions, high amplitude efficiency for at least 50 cycles, and rapid response within seconds. Our molecular switch system has high reproducibility and simple operation by using pH stimulus.