A new unsymmetrical azine derivative based on coumarin group as dual-modal sensor for CN- and fluorescent "OFF-ON" for Zn2.

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/H2O (3:7, v/v). The detection limit on fluorescence response of the sensor to CN- is down to 1.69×10-7M. 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.