A novel voltammetric sensor for the simultaneous detection of Cd2+ and Pb2+ using graphene oxide/κ-carrageenan/l-cysteine nanocomposite.

Simultaneous determination of Cd2+ and Pb2+ was achieved by using graphene oxide/κ-carrageenan/l-cysteine (GO/κ-Car/l-Cys) nanocomposite modified glassy carbon electrode (GCE) by Square Wave Anodic Stripping Voltammetry (SWASV). The morphology and functionalization of the prepared nanocomposite were characterized by XRD analysis, Raman spectroscopy, Field emission scanning electron microscopy and FTIR analysis. Under optimum conditions, outstanding linearity was obtained for both Cd2+ and Pb2+ in the range from 5 to 50nM with the detection limits as 0.58nM and 1.08nM respectively. The sensitivity calculated from the slope of calibration curve was 1.39μA/nM and 1.32μA/nM for Cd2+ and Pb2+ respectively. We also carried out multiple metal ion detection, interference of anions and surfactants for the detection of Cd2+ and Pb2+ ions. The modified electrode has been applied to the detection of Cd2+ and Pb2+ present in water and milk samples, and the accessed results were satisfactory with that of AAS.