A Highly Selective Turn-On Fluorescent Probe for the Detection of Zinc.

A novel turn-on fluorescence probe has been designed that exhibits high selectivity and sensitivity with a detection limit of 9.53 × 10 mol/L for the quantification of Zn. H-NMR spectroscopy and single crystal X-ray diffraction analysis revealed the unsymmetrical nature of the structure of the Schiff base probe . An emission titration experiment in the presence of different molar fractions of Zn was used to perform a Job's plot analysis. The results showed that the stoichiometric ratio of the complex formed by and Zn was 1:1. Moreover, the molecular structure of the mononuclear Cu complex reveals one ligand coordinates with one Cu atom in the asymmetric unit. On adding CuCl to the ZnCl/ system, a Cu-Zn complex was formed and a strong quenching behavior was observed, which inferred that the Cu displaced Zn to coordinate with the imine nitrogen atoms and hydroxyl oxygen atoms of probe .