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(2+)) 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(2+). Owing to the negatively charged channel walls and ultrasmall pore diameter, VMSF displays obvious cationic selectivity and has highly electrostatic interaction for Hg(2+), giving rise to the strong electrochemical signals. By recording the anodic stripping signals of adsorbed Hg(2+) using differential pulse voltammetry, quantitative detection of Hg(2+) 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(2+) in pharmaceuticals and soil samples without tedious pretreatment processes of samples.