A novel method for Hg²⁺ detection with nafion-stabilized Au(I)–alkanethiolate nanotubes modified glassy carbon electrode has been developed on the basis of the high-affinity metallophilic interaction between Hg(II) and Au(I). Under optimum conditions, this method exhibits two good linear correlations in the concentration range of 1–100 nM and 100–1000 nM respectively, while the detection limit is 0.5 nM.