A novel voltammetric sensor for mercury(II) based on mercaptocarboxylic acid intercalated layered double hydroxide nanoparticles modified electrode

A sensitive and Selective electrochemical sensor based on thioglycolic acid intercalated Mg-Al LDH (Mg-AI-TGA LDH) modified electrode was described for the determination of trace mercury using square wave anodic stripping voltammetry (SWASV). The morphology and structure of the synthesized LDHs were characterized using transmission electron microscopy, Fourier transform IR and X-ray diffraction. Several variables affecting the stripping peak current such as the supporting electrolytes, pH value, deposition potential and deposition time, were carefully optimized. Under optimal conditions, the proposed sensor exhibited a wider linearity range from 2.0 to 800 nM Hg(II) with a detection limit of 0.8 nM (S/N = 3), which was below the guideline values in drinking water given by the World Health Organization. The effect of some potentially interfering ions were also investigated and results indicated that the presence of major cations and anions has no obvious influence on the determination of Hg(II). This newly prepared sensor was successfully applied to determination of Hg(II) in water samples with good recovery, ranging from 97 to 104%. (C) 2017 Elsevier B.V. All rights reserved.