Coumarin–TPA derivative: a reaction-based ratiometric fluorescent probe for Cu(I)

A coumarin-based reactive probe 1 is reported for the highly selective detection of Cu+. The benzylic ether (C–O) bond of probe 1 can be cleaved selectively by the reaction with Cu+ under a physiological reducing environment, resulting in a fluorescent change. The maximum emission peak exhibited a red shift from 410 nm to 472 nm, and a remarkable enhancement of emission intensity ratios (I472/I410) from 0.26 to 13.82 was observed.