Fabrication of a Novel Electrochemical Sensor for Simultaneous Determination of Toxic Lead and Cadmium Ions

Background: Highly sensitive and rapid monitoring of heavy metal ions such as lead and cadmium has attracted considerable interest in analytical chemistry due to serious environmental effects of these ions. Objectives: In this work, clay/carbon nanocomposite modified with an organic ligand was applied as a novel modifier for simultaneous measurement of Pb (II) and Cd (II) in water samples. Methods: The characterization of the modifier was studied by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. The analytical performance of the method was investigated by the differential pulse anodic stripping voltammetric (DPASV) technique using a carbon paste electrode (CPE) modified with the prepared nanocomposite. Results: Under the selected optimized conditions, a linear voltammetric response in the range of 2.0 - 100.0 ppb was obtained for the both analyte ions. The calculated detection limits (S/N = 3) were found to be 1.1 ppb for Pb (II) and 0.7 ppb for Cd (II), which are below the World Health Organization (WHO) guideline values for lead and cadmium in drinking water. The method was successfully applied for determination of noxious Pb (II) and Cd (II) ions in real waters with acceptable recoveries for the spiked samples. Conclusions: A simple, selective and sensitive electrochemical sensor was prepared and applied for simultaneous detection of Pb (II) and Cd (II). The suggested sensor demonstrated good electrochemical performance and anti-interference capability for electrochemical detection of these ions in real water samples using the DPASV method.