Preparation and utilization of a new TPM potentiometric sensor as a high-sensitivity, efficient, and stable sensor for Pb2+ detection.

Lead is a heavy metal used in many applications and is often mixed into water resources for various reasons. The rapid detection of Pb2+ ions in aquatic environments plays a very effective role in preventing lead-related diseases. In this study, we developed a new potentiometric sensor using the thiophanate-methyl (TPM) compound, which was used selectively, sensitively, and stably in Pb2+ detection. The performance test of the potentiometric sensor was performed in various Pb2+ solutions, and it was found that the TPM structured sensor has a high correlation coefficient (R2 = 0.9996) and a very low detection limit (LOD: 1.5 × 10-8 M). The reliability of the TPM sensor in Pb2+ detection was confirmed by experimental studies that included response time, pH (4-12) range, titration, and lifetime (four weeks). LC-MS/MS, FTIR analyses, and DFT studies were performed to reveal the interactions between Pb2+ and the TPM compound. A comparison of LC-MS/MS, FTIR analyses, and DFT calculations showed that Pb2+ was bound to the TPM molecule through S atoms. In addition, the Pb2+ detection findings obtained with the potentiometric sensor were confirmed by LC-MS analysis. The experimental results showed that a potentiometric sensor containing TPM was successfully developed and used to detect Pb2+ ions.