Highly selective fluorescent probe for the detection of tin (IV) Ion

A novel fluorescent compound, 7-diethylamino-3-(2'-(1H-imidazo[4,5-b]phenazine)yl)coumarin (DIPC), was synthesized and employed as a fluorescent probe for detecting tin (IV) ion. Upon addition of tin (IV) ion to the solution of DIPC in DMSO-water (9:1, v/v), DIPC exhibited a considerable red-shift in its absorption spectrum and a decrease in fluorescence intensity. These changes result from tin (IV) ion binding to carbonyl oxygen of coumarin and nitrogen of imidazole, reflecting an enhanced ICT process from N,N-diethylamino unit to imidazole unit. The tin (IV) ion selective response was clearly observed by the naked eye through color change. We also studied the bioimaging application of DIPC for detecting tin (IV) ion in Hela cells. And a significant decrease of the fluorescence from the intracellular area was observed.