Vertically-Ordered Mesoporous Silica Films for Electrochemical Detection of Hg(II) Ion in Pharmaceuticals and Soil Samples.

Rapid and simple determination of mercury ion (Hg) in pharmaceuticals and soil samples is vital for human health and the environmental monitoring. Vertically-ordered mesoporous silica films (VMSF) supported by the indium tin oxide (ITO) electrode surface were prepared by electrochemically assisted self-assembly method and utilized for electrochemical detection of Hg. Owing to the negatively charged channel walls and ultrasmall pore diameter, VMSF displays obvious cationic selectivity and has highly electrostatic interaction for Hg, giving rise to the strong electrochemical signals. By recording the anodic stripping signals of adsorbed Hg using differential pulse voltammetry, quantitative detection of Hg was achieved with a wide linear range (0.2 μM-20 μM) and a low limit of detection (3 nM). Furthermore, considering the anti-fouling and anti-interference capacity of VMSF, the proposed VMSF/ITO sensor has been successfully applied to detect Hg in pharmaceuticals and soil samples without tedious pretreatment processes of samples.