Simultaneous electrochemical detection of Cd and Pb using a green silver nanoparticles/polyaniline-modified carbon paste electrode.

In this study, a novel electrochemical sensor based on a carbon paste electrode (CPE) modified with polyaniline (PANI) and green-synthesized silver nanoparticles (AgNPs) was developed for the simultaneous detection of cadmium (Cd) and lead (Pb) ions in aqueous solutions. The AgNPs were synthesized using a green route employing plant extract as a reducing and capping agent, ensuring environmental sustainability. The modified electrode (AgNPs-PANI-CPE) was characterized by UV-Vis spectroscopy, field-emission gun scanning electron microscopy (FEG-SEM), and simultaneous thermal analysis (TGA/DSC). The electrochemical behavior of Cd and Pb was investigated using square wave voltammetry (SWV) and CV. The sensor exhibited distinct and well-separated anodic peaks for Cd and Pb, with excellent sensitivity, wide linear response ranges, and low detection limits (0.09 and 0.05 μg L, respectively). Interference studies demonstrated good selectivity towards the target ions, and successful application to real water samples confirmed its analytical performance. This work highlights the potential of eco-friendly nanocomposite-modified electrodes in environmental monitoring of toxic heavy metals.