A New Coumarin-Based Fluorescent Chemosensor for Selection Detection of Zinc Ions in Aqueous Ethanol.

In this study, a coumarin-based Schiff base (1) was designed and synthesized as a Zn2+-selective fluorescent chemosensor based on the PET mechanism. The structure of compound 1 was characterized by 1H NMR and 13C NMR. The fluorescence properties of this chemosensor toward various metal ions were explored by fluorescence and UV-vis spectra. The results indicated that the chemosensor had high selectivity toward Zn2+ over other coexisting metal ions. The binding stoichiometry of 1 toward Zn2+ was determined to be 1:1 by Job's plot. Furthermore, the chemosensor was reversible for Zn2+ in an ethanol/H2O (7:3, V/V) solution by the addition of Na2 EDTA. The above experimental results demonstrate that 1 can be used as a fluorescent chemosensor for the real-time detection of Zn2+ in biological species and environmental systems.