A simple quinoline-based fluorescent “turn on” probe with high selectivity for Ag+ in aqueous media

•A simple quinoline-based fluorescent probe L has been developed.•Probe L exhibits a significant fluorescent enhancement toward Ag+ with high selectivity in aqueous media.•Probe L shows good fluorescence sensing ability to Ag+ over a wide pH range (from 6.0 to 12.0).•The response of the probe L toward Ag+ is fast.•The 1:1 binding mode between L and Ag+ was demonstrated by X-ray crystal diffraction.

A simple quinoline-based fluorescent probe L for Ag+ has been developed. Probe L shows fluorescence enhancement (turn on) response towards Ag+ with high selectivity in aqueous media (methanol–water, v/v = 3:7, pH 7.2, 20 mM Tris–HCl) based on a combinational effect of the inhibition of intermolecular photoinduced proton transfer and chelation-enhanced fluorescence. And an obvious fluorescent color change could be observed by naked eyes under the light of 365 nm. The binding mode between L and Ag+ has been found to be 1:1 based on the fluorescence/absorption titration, ESI-MS and further confirmed by X-ray crystallography.

Graphical abstractA simple quinoline-based fluorescent probe L has been developed and shows fluorescence enhancement (turn on) response towards Ag+ with high selectivity in aqueous media based on a combinational effect of the inhibition of intermolecular photoinduced proton transfer and chelation-enhanced fluorescence.Figure optionsDownload full-size imageDownload as PowerPoint slide