A new unsymmetrical azine derivative based on coumarin group as dual-modal sensor for CN− and fluorescent “OFF–ON” for Zn2 +

Abstract

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.