Highly Sensitive and Selective Detection of Hg²⁺ ions and Antibacterial Activity Using a Schiff-base Derivative

A simple and highly effective Schiff-base fluorescent chemosensor (S1) was synthesized and characterized by ¹HNMR and fluorescence spectroscopy. The synthesized chemosensor was applied for the selective and sensitive detection of Hg²⁺ ions. The chemosensor exhibited a strong 'turn-on' fluorescence response in a CH₃OH/H₂O (1:9, v/v) solution due to complex formation (S1-Hg²⁺) which block photo induce electron transfer (PET). The chemosensor showed significant sensitivity with very low detection limit of 2.0 ppb, making it suitable for trace-level Hg²⁺ detection. Furthermore, the S1-Hg²⁺ complex demonstrated excellent antibacterial activity against various Gram-positive and Gram-negative bacterial strains, broadening its utility beyond sensing. This dual-functional system offers significant potential in environmental and biomedical applications.