Fe3+-selective fluorescent probe based on rhodamine B and its application in bioimaging

A Rhodamine-based fluorescent and colorimetric chemosensor for Fe3+ ion, acetyl rhodamine-hydroxamate (ARH), was designed and synthesized. Upon mixed with Fe3+ in CH3CN–H2O (1:1, v/v), the spirolactam of ARH was opened, which resulted in the dramatic enhancement of both fluorescence and absorbance intensity as well as the color change of the solution. Background metal ions showed small or no interference with the detection of Fe3+. The Job's plot indicated the formation of 1:1 complex between ARH and Fe3+. Confocal laser scanning microscopy experiments showed that ARH could be used to detect Fe3+ in living cells.