An “AIE + ESIPT” mechanism-based benzothiazole-derived fluorescent probe for the detection of Hg2+ and its applications

Abstract

Mercury ion (Hg²⁺) contamination is very hazardous and harmful to the natural environment and human health. The development of small molecule fluorescent probes for the rapid detection of Hg²⁺ is of great significance. In the present work, an “AIE + ESIPT” mechanism-based benzothiazole derived fluorescent probe was applied to Hg²⁺ detection and displayed excellent selectivity, good anti-interference ability, low detection limit (2.85 × 10⁻⁹ M), and a large Stokes shift (170 nm) in the DMF/H₂O mixture solution with f_w = 60% H₂O volume fraction. The fluorescence response mechanism, involving the desulfurization reaction of O-(2-(benzo[d]thiazol-2-yl)-6-formyl-4-methylphenyl)dimethylcarbamothioate (probe L) with Hg²⁺ to release the “AIE + ESIPT” fluorophore, was well established based on the UV-vis, ¹H NMR, and HRMS spectral analyses. The practical application evaluation indicates that probe L could be used to precisely determine Hg²⁺ in live cell imaging, natural water, and seafood samples.