A nanocomposite consisting of ionic liquid-functionalized layered Mg(II)/Al(III) double hydroxides for simultaneous electrochemical determination of cadmium(II), copper(II), mercury(II) and lead(II).

An electrochemical sensor is described for the simultaneous determination of Cd2+, Cu2+, Hg2+ and Pb2+ using square wave anodic stripping voltammetry. A glassy carbon electrode (GCE) was modified with N,N-dimethyl-N-2-propenyl-2-propen-1-aminium chloride homopolymer ionic liquid doped into magnesium(II)-aluminium(III) layered double hydroxides. The morphology investigations suggest that the material possesses typical interconnected laminated micropores and a mesoporous architecture dispersed on the surface of the GCE. This accelerates mass diffusion and facilitates the deposition-stripping process of metal ions. Key operational parameters including pH, deposition potential, deposition time and the quantity of nanomaterial on the GCE were optimized. The following figures of merit for the ions Cd2+, Cu2+, Hg2+ and Pb2+ are obtained under optimum conditions: (a) detection limits of 250, 25, 250 and 16 ng L-1; (b) linear ranges from 0.5 to 20, 0.05 to 20, 0.5 to 20 and 0.05 to 20 μg L-1, and (c) peak potentials of -768, +42, +302 and - 541 mV (vs. Ag/AgCl). The modified GCE was successfully applied to the determination of these ions in spiked black tea extract and in dried tangerine peel. Graphical abstractSchematic representation of novel electrochemical sensor based on a glassy carbon electrode modified with IL-Mg/Al-LDHs composites for the simultaneous detection of Pb2+, Cd2+, Cu2+ and Hg2+.