Reversible Fluorescent Turn-on Sensors for Fe3+ based on a Receptor Composed of Tri-oxygen Atoms of Amide Groups in Water

Compounds Rh6G-1 and RhB-2 with a novel receptor composed of tri-oxygen atoms of amide groups were designed and synthesized as new reversible fluorescent sensors for Fe. The prominent features of the novel sensor Rh6G-1 include a large fluorescence turn-on response in essentially pure water at room temperature, high sensitivity, high selectivity, a limit of detection, cell membrane permeability, and low cytotoxicity. These desirable attributes enable us to successfully employ the new sensor Rh6G-1 for Fe3+ bioimaging in living cells.