A facile Zn(II) probe based on intramolecular charge transfer with fluorescence red-shift

A simple fluorescent probe comprised of coumarin and quinoline units was designed and synthesized through acylhydrazine bonding mode. On account of the "push-pull" structure, the probe exhibits high selectivity and sensitivity for Zn(II) with an obvious red-shift of fluorescence and a visible color change. The detection of Zn(II) by the probe is almost free from interference of other ions and reversible based on intramolecular charge transfer process. Three five-membered rings of the probe with Zn(II) were formed and verified by MS and H-1 NMR spectra. Notably, as a simple, fast and environmentally friendly device, detection of ions by test paper has great practicality, the probe could be designed as test papers for detecting Zn(II) taking advantage of the color change character under 365 nm UV lamps.