Specific size-matching strategy for electrochemical selective and sensitive detection of mercury(II) based on a three-dimensional-gap-net in a Au–thiol coordination polymer

•A porous Au–thiol metal–organic coordination polymer has been synthesized.•The polymer is used for the detection of mercury ions.•The sensitivity and limit of detection reach 0.075 μA nM− 1 and 12 nM, respectively.•The mechanism of detection is based on specific size-matching strategy.

A novel specific size-matching strategy for electrochemical selective and sensitive detection of Hg(II) has been designed based on a porous Au–thiol metal–organic coordination polymer. The sensitivity and limit of detection reach 0.075 μA nM− 1 and 12 nM, respectively. The mechanism of detection is assumed that Hg(II) ions are deposited into the three-dimensional (3D)-gap and form a contact among the Au metal, which triggers an electrochemical response.