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

Article abstract of DOI:10.1016/j.tetlet.2012.12.054

A new quinoline based fluorescent probe (DQ) for Zn²⁺ and Cd²⁺ has been designed and synthesized. The new probe shows quite different fluorescence response to Zn²⁺ and Cd²⁺ in aqueous solution. IR and NMR spectra demonstrated that the different response is caused by amide tautomerization of the probe molecule when coordinating with Zn²⁺ and Cd²⁺. The dissociation constants of Zn ²⁺ and Cd²⁺ 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 Zn²⁺ and Cd²⁺ in water with high selectivity and sensitivity.