A new electrochemical sensor for simultaneous determination of Cd (II) and Pb (II) using FeNi3/CuS/BiOCl: RSM optimization

In this study, an electrochemical sensor has been made to detect Cd (II) and Pb (II) on the carbon electrode (CPE) modified with the FeNi3/CuS/BiOCl nanocomposite. In addition, we utilized square wave anodic stripping voltammograms (SWASV) technique to detect the target metal ions. Moreover, an experimental design has been used to examine and optimize the impacts of diverse experimental parameters like the pH of the solution, accumulation potential, accumulation time, and concentration of the nanocomposite as a modifier in CPE. As FeNi3, CuS and BiOCl nanoparticles (NPs) have synergetic effects, FeNi3/CuS/BiOCl/CPE presented very good mechanical stability and electrical conductivity in the presence of Pb (II) and Cd (II) ions. Upon the optimization of the conditions, the newly designed sensor exhibited completely wide linear ranges of 1.0 and 150.0 μg/L; and 0.5 to 120.0 μg/L and LOD 0.4 μg/L and 0.1 μg/L for Cd (II) and Pb (II), respectively. The modified CPE displayed considerable reliability, reproducibility, stability, and selectivity. Moreover, detecting cadmium (II) and lead (II) ions in food samples illustrated very good practicability of the new modified carbon paste. © 2020 Elsevier B.V