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.