Green synthesis of thiazole bis-imines as fluorometric sensor for determination of lead in environmental, biological, and food samples.

In this work, we describe for the first time the synthesis of a thiazole bis-imine fluorometric sensor for the selective determination of Pb in environmental, biological, and food samples. The novel molecules were obtained through a multicomponent reaction using a green and environmentally sustainable methodology. Synthesized chemical sensors were characterized using spectroscopic techniques to structural elucidation, including UV-Vis, FTIR-ATR, H and C NMR. One of these sensors exhibited remarkable selectivity for the Pb ion at pH 3, forming a stable 1:1 (metal:ligand) complex. Additionally, the reaction conditions for complex formation were optimized, resulting in a method with a linear range of 0.667-10  μg L and a detection limit of 0.18  μg L. Furthermore, method validation reinforced its reliability, showing low relative standard deviation in both intra-day and inter-day analyses. Recovery experiments ranged from 83.53 % to 119.10 %. This study represents a significant and innovative advancement in the development of rapid, sensitive, and alternative methods for the detection of potentially toxic metals in a wide range of samples employing a green multicomponent reaction of thiazole bis-imines.