Fast and Reversible "Turn on" Fluorescent Sensors Based on Bisphenol-a for Zn in Aqueous Solution.

Two novel bisphenol-A derivatives (R1 and R2) linked pyrene and napthylthiazole moieties were synthesized via condensation reaction, and positively applied for the selective recognition of Zn ion in EtOH/HO. Their optical properties were observed by using UV-vis and fluorescence measurements. R1 and R2 exhibited high selectivity and sensitivity towards Zn over other metal ions. This fluorescence selectivity may be owing to inhibited excited-state intramolecular proton transfer (ESIPT) and photoinduced electron transfer (PET). The fluorescence titration analysis indicated detection limits of R1 and R2 for Zn at 17.5 nM and 0.94 μM, respectively. Moreover, R1 and R2 were successfully applied to the detection of Zn with different concentrations in water samples.