Tin nanoparticle-modified electrode for the simultaneous detection of cadmium (Cd) and lead (Pb) ions

Heavy metals are toxic and persistent in the environment and can accumulate in the food chain and potential health hazards to humans and other living organisms. Exposure to heavy metals can cause a range of health effects, including neurological damage, developmental and reproductive problems, and increased risk of certain types of cancer. Thus, monitoring the levels of heavy metal ions in the environment is essential. In these studies, tin nanoparticles (SnNPs) were synthesized using the chemical reduction method to modify the electrode surface on an indium tin oxide (ITO) electrode for heavy metal detection. Two approaches were used in synthesis of SnNPs: one with the presence of polyvinylpyrrolidone (PVP) polymers, namely, SnNP WPVP and the other was performed without a PVP polymer, namely, SnNP WOPVP. The modified electrode was subjected to cyclic voltammetry and square wave anodic stripping voltammetry. The electrode modified with Nafion/100 × SnNP WPVP/ITO showed good performance in the simultaneous detection of Cd²⁺ and Pb²⁺ ions and had a linear range of 10–100 ppb, and the low limits of detection for the simultaneous detection of Cd²⁺ and Pb²⁺ ions were 1.44 and 1.97 ppb, respectively. The sensitivity of the Nafion/100 × SnNP WPVP/ITO–modified electrode was 0.25 and 0.20 μA/ppb toward Cd²⁺ and Pb²⁺ ions, respectively. In the interference study, the modified electrode showed high selectivity towards Cd²⁺ and Pb²⁺ ions. The feasibility of using the modified electrode in detecting Cd²⁺ and Pb²⁺ ions was tested in a seawater sample. The successful detection of Pb²⁺ in seawater demonstrated the potential of the modified electrode as a heavy metal ions sensor.