Sulfur‐Doped g‐C ₃ N ₄ /Nafion Based Electrochemical Platform for the Trace Level Detection of Pb ²⁺

The presence of lead Pb ²⁺ in drinking water pose a significant risk to human health if its concentration exceeds permissible limits. Thus, the detection of Pb ²⁺ is essential for assessing water quality and facilitating its real‐time assessment. Here, S‐g‐C ₃ N ₄ is synthesized via a one‐pot thermal polymerization synthesis, modified with nafion (Nf) and named as S‐g‐C ₃ N ₄ /Nf/GCE. This modified material is employed for the selective detection of Pb ²⁺ in trace levels by differential pulse anodic stripping voltammetry (DPASV). The performance of the S‐g‐C ₃ N ₄ /Nf/GCE electrochemical sensor is optimized for operational parameters, namely deposition potential, time, and pH of electrolyte. The electrochemical sensor showed an excellent linear response towards Pb ²⁺ detection in the 5 nM–2.5 µM range. The sensor demonstrated a limit of detection (LOD) of 0.16 ± 0.004 nM and a sensitivity of 93.03 μA cm ⁻² μM ⁻¹ . The electrochemical sensor displayed very high selectivity towards Pb ²⁺ especially in the coexistence of other metal ions such as Na ⁺ , Ca ²⁺ , K ⁺ , Ni ²⁺ , Co ³⁺ , Cd ²⁺ , Cu ²⁺ , and Hg ²⁺ . The real‐time effectiveness of the electrochemical sensor is validated by employing it in tap water sample.