A simple fluorescent probe for selectively detecting Al³⁺ and F^- in living cells and growing tea plants

Aluminum (Al³⁺) and fluorine (F^-) ions can be easily enriched in tea plants. When they excessively accumulate in tea, they can affect the health of tea lovers. Herein, a simple, highly sensitive and selective fluorescent probe (named BHMP) for Al³⁺ and F^- detection was developed through a one-step condensation reaction, in which benzothiazole acted as a fluorophore and acceptor and hydrazine-Schiff base as a recognition unit. The probe was characterized comprehensively using spectroscopic methods, and the structure-activity relationship was systematically researched through crystal structure and theoretical calculations. Its sensitivity was measured via the fluorescent titration experiment, and the limit of detection (LOD) towards Al³⁺ was up to 1.04 × 10^-8 mol L^-1. Furthermore, we successfully utilized BHMP to visually detect the presence of Al³⁺ in living cells and tea tree roots through fluorescence confocal imaging. The successful detection of Al³⁺ in tea tree roots indicated that BHMP could be used as a candidate fluorescent chemosensor to dynamically monitor the variation in enriched Al³⁺ under the influence of the environment during tea tree growth. Our study provides a reference for the control of Al³⁺ concentration during the growth of tea plants and provides new insights into improving tea quality control.