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

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. [ABSTRACT FROM AUTHOR]