A 3-hydroxyflavone derivative as fluorescence chemosensor for copper and zinc ions

A 3-hydroxyflavone derivative as fluorescence chemosensor for copper and zinc ions has been synthesized. Its recognition properties for copper and zinc ions in aqueous solution were investigated based on UV-vis absorption and fluorescence spectra change. The compound exhibits color change from colorless to yellow and quenching of green fluorescence in the presence of copper ions in aqueous solution due to coordination reaction. In turn, the addition of zinc ions induces the color change from colorless to green and fluorescence enhancement of the compound. The complex ratios between the sensor molecule and copper(zinc) ions are 1:1 and 1:2, respectively, based on the Job's plots and in situ mass spectra. Thus, this compound can selectively recognize copper and zinc ions, and the recognition also can be observed by naked eye.