A new Zn2+ chemosensor based on functionalized 8-hydroxylquinoline

A new fluorescent Zn2+ chemosensor (3) based on functionalized 8-hydroxylquinoline has been synthesized and characterized. Compound 3 shows weak fluorescence in CH3CN–HEPES buffer solution (50 mM, pH 7.2 v/v = 1:9), but the fluorescence is significantly enhanced upon binding to Zn2+ through a zinc(II)-catalyzed ester hydrolysis reaction to form a highly emissive zinc(II) complex. This suggests that 3 can be served as a typical “switch–on” chemosensor with high selectivity for Zn2+ over other metal ions.