Fluorescence enhancement of coumarin–quinoline by transition metal ions: Detection of paramagnetic Ni 2+ and Co 2+

Abstract

A readily available coumarin–quinoline was employed as a novel fluorescent probe for paramagnetic Co 2+ and Ni 2+ ions, which are well-known fluorescence quenchers. NMR and IR indicated that the enhanced fluorescence response was attributable to coordination of the paramagnetic Ni 2+ or Co 2+ ions with the coumarin–quinoline compound. Given the difficulty of designing enhanced fluorescent probes for paramagnetic Co 2+ and Ni 2+ ions, the coumarin–quinoline compound may inspire the further development of more sophisticated sensing constructs for the fluorescence detection of these transition metal ions.