A quinoline based fluorescent probe that can distinguish zinc(II) from cadmium(II) in water

摘要

A new quinoline based fluorescent probe (DQ) for Zn~(2+) and Cd~(2+) has been designed and synthesized. The new probe shows quite different fluorescence response to Zn~(2+) and Cd~(2+) in aqueous solution. IR and NMR spectra demonstrated that the different response is caused by amide tautomerization of the probe molecule when coordinating with Zn~(2+) and Cd~(2+). The dissociation constants of Zn~(2+) and Cd~(2+) complex were detected to be 3.36 and 30.62 nM, respectively. Other metal ions have no effect on the fluorescence spectrum of the probe. Thus the new probe can detect Zn~(2+) and Cd~(2+) in water with high selectivity and sensitivity.