A novel electrochemical sensor based on Co3O4-CeO2-ZnO multi metal oxide nanocomposite for simultaneous detection of nanomolar Pb2+ and Hg2+ in different kind of spices

摘要

Simultaneous and individual determination of Pb2+ and Hg2+ ions have been carried out based on the synergistic effect of Co3O4, CeO2 and ZnO nanoparticles onto the carbon paste electrode. The morphology of synthesized nanocomposite (Co3O4-CeO2-ZnO) has been investigated by Scanning Electron Microscope, Transmission Electron Microscope, X-ray diffraction and Fourier Transform Infrared spectroscopy. The voltammetric current has been increased linearly by increasing the concentration of Pb2+ and Hg2+ ions. The linear ranges of the Co3O4-CeO2-ZnO/CPE sensor have been obtained 0.27-18.42 nM (for Pb2+ ions) and 0.42-31.30 nM (for Hg2+ ions), under optimum condition. The detection limits (3S(b)/m) have been obtained 0.054 nM for Pb2+ and 0.097 nM for Hg2+, respectively. The proposed electrochemical sensor acts as a sensitive and selective method for simultaneous determination of two heavy metal ions and shows excellent repeatability, reproducibility, and stability, with relative standard deviation (RSD) less than 3%. Finally, Co3O4-CeO2-ZnO/CPE has been successfully applied for the determination of Pb2+ and Hg2+ in different kind of spices.