A novel phenol-based BODIPY chemosensor for selective detection Fe3+ with colorimetric and fluorometric dual-mode

A novel BODIPY-based colorimetric fluorescent chemosensor (L) with phenol as binding site for Fe3+ has been developed. L is capable of showing high selectivity and sensitivity toward Fe3+ with little interference from Al3+/Cr3+. In presence of Fe3+, L shows a significant blue-shift in the absorption spectra from 571 to 502 nm and an increase of the ratio of the absorbance at 502 and 571 nm (A502/A571) over 268-fold, which induces color changes from pink to yellow. Upon excitation at 502 nm, L upon interaction with Fe3+ ions displays a 40-fold fluorescence enhancement and blue-shifts from 604 to 530 nm, resulting in emission color change from orange to green. The binding mode of L with Fe3+ has been investigated by Job's plot, MALDI-TOF-MS and FT-IR experiments. In addition, the cell imaging experiments demonstrate that L can be successfully applied as a bioimaging agent for monitoring Fe3+ in cells.