A long lifetime iridium(III) complex as a sensitive luminescent probe for bisulfite detection in living zebrafish.

A long-lived iridium(III) complex probe Ir_1 for bisulfite detection has been synthesized. The iridium(III) complex probe Ir_1 , containing double aldehyde groups in the N^N donor ligand, can react with bisulfite to form an adduct with enhanced luminescence. The interaction of probe Ir_1 with bisulfite was investigated through NMR and emission titration experiments. Upon the addition of bisulfite, probe Ir_1 displayed more than a 4-fold luminescence enhancement, and a detection limit of 0.35 μM was recorded. Probe Ir_1 shows a large Stokes shift (280 nm) and a long-lived luminescence which allows it to be distinguished from autofluorescent media through time-resolved emission spectroscopy (TRES). Finally, the applications of probe Ir_1 to the detection of bisulfite in living cells and zebrafish were described. [ABSTRACT FROM AUTHOR]