FRET-based ratiometric fluorescent probe for Cu 2+ with a new indolizine fluorophore.

A new fluorophore indolizine was synthesized and used as a donor to construct FRET system. The chemodosimeter shows a large Stokes shifts (193 nm), high sensitivity, and high selectivity. The probe can quickly (10 min) detect Cu2+ effectively in a wide pH range from 5 to 12 and with a detection limit as low as 9.1 × 10-9  M. Furthermore, it could be used for imaging Cu2+ in living Glioma cells which demonstrated its value of practical applications in biological systems.