Quinoline containing acetyl hydrazone: An easily accessible switch-on optical chemosensor for Zn 2 .

A simple chemosensor, namely, N-((quinolin-8-yl)methylene)acetohydrazide (1) was synthesized and used as an off-on fluorescence sensor, which exhibits high selectivity toward Zn2+ in aqueous media. The probe has large Stokes shift of >200nm, and its detection limit for Zn2+ is 89.3nM. The binding process was confirmed through UV-vis absorption analysis, fluorescence measurements, mass spectroscopy study, 1 H NMR spectra and density functional theory calculation. The crystal structures of Zn2+ , Ni2+ , and Cu2+ complexes based on 1 were determined through X-ray crystallographic analysis. The fluorescent probe was then applied to monitor intracellular Zn2+ in HeLa cells.