A highly selective, fluorescent chemosensor for bioimaging of Fe3+

A fluorescent sensor for Fe3+ has been synthesized based on rhodamine-lactam, which shows excitation (531 nm) and emission (557 nm) wavelength, displays an excellent selectivity for Fe3+ and can be used for imaging Fe3+ in living cells. The pKa of the sensor is as low as of 3.2. It can be used in the range of pH 5-9.