The ratiometric fluorescent sensor L based on 8-hydroxyquinoline has been designed and synthesized. In aqueous media, L exhibits a ratiometric response to Ag+ in the presence of competing metal ions with a large blue-shift of 76 nm. The good linear relationship is easily obtained between the fluorescence changes and the concentrations in the range of 0–80 μM. The complexation mode has been proposed by fluorescence titration, 1H NMR, IR and MS mass spectrometer experiments.
