Synthesis, crystal structure and living cell imaging of a Cu(2+)-specific molecular probe.

We report the development of a rhodamine chromene-based fluorescence probe to monitor the intracellular Cu(2+) level in living cells. The new fluorescent probe exhibits a fluorescence response towards Cu(2+) under physiological conditions with high sensitivity and selectivity, and facilitates the naked-eye detection of Cu(2+). The fluorescence intensity was significantly increased by about 40-fold with 10 equiv. of added Cu(2+).