Dual-function thiourea-linked benzothiazole derivative: sensitive fluorescent detection of Hg2+ and broad-spectrum antibacterial and antifungal activity.

A novel thiourea-linked benzothiazole derivative TH1 was synthesized and systematically characterized for its dual-functional application in sensing and antimicrobial activity. The compound exhibited excellent selectivity and sensitivity toward Hg2+ ions, with a clear fluorescence quenching ("turn-off") response upon binding due to formation of TH1-Hg(II) complex. The probe demonstrated a remarkably low detection limit of 0.019 ppm, making it suitable for trace-level mercury detection. Interference studies confirmed its high selectivity, and practical applicability was validated by testing blood serum and various real water samples including river, pond, lake, river and drinking water as well as soil sample with percent recovery rates ranging from 89.0 ± 0.54% to 102.0 ± 0.74%, confirming its reliability and accuracy in complex environmental matrices. Beyond its sensing capabilities, the benzothiazole-thiourea TH1 and complex TH1-Hg(II) also showed promising broad-spectrum antimicrobial activity. Both ligand and its complex effectively inhibited the growth of bacterial and fungal strains, producing well-defined zones of inhibition. This dual-functionality, highly sensitive Hg2+ detection and notable antibacterial performance, positions the TH1 as a strong candidate for multifunctional applications in environmental monitoring and biomedical fields.