A “turn-on” Schiff base fluorescent probe for recognizing Zn2+ and its application in indictor and imaging of zebrafish

A novel fluorescent probe was designed and synthesized by using benzothiazole ring as fluorophore to specifically recognize Zn2+ in aqueous solution. In methanol and aqueous mixed solution, the probe had a significant fluorescence enhancement response to zinc ions and indicated high selectivity and sensitivity. Through fluorescence titration, 1H NMR titration, Job's plot, HRMS data and DFT calculation, the binding ratio of the probe to Zn2+ was 2: 1, and the detection limit was 2.85 × 10-8 M. The probe was further applied to actual water sample to detect Zn2+, and the medium-speed filter paper was combined with probe solution to make an indicator to detect Zn2+ more conveniently and quickly. More importantly, the probe could detect Zn2+ in zebrafish from the results of fluorescence imaging, which proved that the probe had a broader prospect in biological field.