Three-dimensional gold micro-/nanopore arrays containing 2-mercaptobenzothiazole molecular adapters allow sensitive and selective stripping voltammetric determination of trace mercury (II)

Three-dimensional (3D) gold micro-/nanopore arrays containing 2-mercaptobenzothiazole (MBT) adapters have been prepared and employed to improve the performance of the determination of trace mercury in solution using square wave anodic stripping voltammetry (SWASV). 3D gold micro-/nanopore arrays have an active surface area which is up to 4 and 15 times higher than a two-dimensional (2D) bowl-like structured microarrays and a flat solid gold electrode characterized by cyclic voltammetry, respectively. In this study, 3D MBT molecular adapters on the array surface greatly decreased the effect of capacitive current and enhanced the sensitivity and selectivity of the electrode. A limit of detection of 0.02 nM (which is well below the guideline given by the World Health Organization) and more importantly, a sensitivity of 1.85 μA nM−1 was obtained using this system. Furthermore, excellent linear range (0.05–10 nM) and good repeatability (relative standard deviation of 2.10%) were obtained for Hg(II). Interference experiments were also investigated, and it was determined that Pb(II), Cd(II), Zn(II), Cu(II) and Ag(I) had little or no influence on the mercury signal.