A fluorescent sensor based on AIE-active tetraphenylethylene-functionalized salicylaldehyde schiff base for Zn ²⁺ detection and its application in real water samples

Fluorescent chemical sensors utilizing aggregation-induced emission (AIE) have emerged as powerful tools for monitoring metal ions relevant to biological and environmental contexts. This study reports the rational design and synthesis of a novel AIE-active luminophore, TPEBA, which is constructed via a Schiff base condensation reaction between 2-hydroxy-5-(1,2,2-triphenylethenyl)-benzaldehyde and 3,5-di-tert-butylaniline. TPEBA serves as a highly selective “turn-on” fluorescent probe for Zn2+ in an ethanol/PBS medium, exhibiting significant fluorescence enhancement and a pronounced blue shift (approximately 51 nm). The sensor achieves an exceptionally low detection limit of 78.3 nM, well below the World Health Organization’s stipulated level, and enables rapid visual discrimination under ultraviolet light. By integrating spectroscopic techniques (Job’s plot, FT-IR) with density functional theory (DFT) calculations, a 1:1 binding stoichiometry and a chelation-enhanced fluorescence (CHEF) mechanism are elucidated. The probe TPEBA exhibits excellent specificity, reversibility with EDTA, and successful applications in water quality analysis and test strips, highlighting its great application potential in practical environmental.