A new unsymmetrical azine derivative based on coumarin group as dual-modal sensor for CN - and fluorescent "OFF-ON" for Zn 2 .

A simple chemosensor YS based on coumarin group was designed and synthesized. Its structure was determined by single crystal X-ray diffraction analysis. In the presence of cyanide the sensor showed an immediate visible change in color from colorless to pale yellow by naked-eyes and produced a strong blue fluorescence rapidly in DMSO/H2 O (3:7, v/v). The detection limit on fluorescence response of the sensor to CN- is down to 1.69×10-7 M. In addition YS could show fluorescence turn-on response rapidly for Zn2+ over other metals ions such as Fe3+ , Hg2+ , Ag+ , Ca2+ , Cu2+ , Co2+ , Ni2+ , Cd2+ , Pb2+ , Cr3+ and Mg2+ in aqueous solutions. Notably, this sensor served as a molecular switch, which was controlled by Zn2+ and EDTA cyclically. Test strips based on YS were fabricated, which could act as a convenient and efficient CN- and Zn2+ test kit. This chemosensor could achieve the detection of two ions, which need not depend on two different sensors.