Beyond conventional sensing: A multifunctional benzothiazole-based fluorophore with ESIPT-AIE-ICT synergy for the ultrasensitive determination of tebuconazole in environmental samples

Herein, we designed a novel benzothiazole-based fluorophore that combines aggregation-induced emission (AIE), excited-state intramolecular proton transfer (ESIPT), and intramolecular charge transfer (ICT) mechanisms in the behavior of “kill three birds with one stone”. The synthesized fluorophore exhibits a high fluorescence quantum yield and a large Stokes shift (> 200 nm) arising from the synergistic effect of the three mechanisms. This enables effective separation of excitation and emission wavelengths, thereby reducing spectral interference and enhancing precision. The synergistic effect of these mechanisms has been thoroughly investigated and utilized as a multifaceted framework for developing an efficient fluorescent probe capable of determining tebuconazole in environmental water and soil samples. The probe demonstrates remarkable fluorescence quenching in the presence of tebuconazole with outstanding sensitivity over a linear range of 0.32–26.0 µM and a low detection limit of 0.08 µM. Furthermore, the quenching mechanisms were investigated. Static quenching was favored, and theoretical simulation studies confirmed the interaction mechanism. This work elucidates the fluorescence mechanisms, providing an innovative approach for the development of advanced probes with enhanced sensitivity across various fields, such as environmental monitoring and chemical analysis.