Three-dimensional gold nanowires with high specific surface area for simultaneous detection of heavy metal ions

Abstract

Traditional detection methods to detect heavy metal ions are time-consuming, complicated, and expensive. Here, we developed a simple electroless plating method to prepare three-dimensional gold nanowire (Au NW) films with high specific surface area. In an aqueous plating bath, tetrachloroauric acid, 4-dimethylaminopyridine and formaldehyde are used as precursor, ligand, and reducing agent, respectively. An electrochemical sensor based on a Au NWs/SPE could be applied for simultaneous detection of lead (Pb(II)), arsenic (As(III)), and mercury (Hg(II)) ions. The detection limits of Pb(II), As(III), and Hg(II) are 2.6, 1.5, and 4.2 μg L⁻¹, all lower than the permissible limits of the WHO for drinking water (the permissible level of Pb(II) and As(III) is 10.0 μg L⁻¹, and the permissible level of Hg(II) is 6.0 μg L⁻¹), respectively. This work presents a simple and novel method to prepare gold nanowires for quick detection of trace heavy metal ions.