Highly sensitive and selective fluorescent sensor for Zn2+/Cu2+and new approach for sensing Cu2+by central metal displacementElectronic supplementary information (ESI) available: Experimental procedures, characterization data, UV-vis absorption and fluorescence spectra. See DOI: 10.1039/c1cc10696a

An “off-on” Zn2+and “on-off” Cu2+fluorescent chemosensor Cwas designed and synthesized. The binding of Cand Zn2+/Cu2+is chemically reversible by the addition of EDTA disodium solution; moreover, the fluorescence emission signal of ZnCdecreased with the addition of Cu2+, demonstrating that ZnCcould detect Cu2+viametal displacement. [ABSTRACT FROM AUTHOR]