Rapid "turn-on" photoluminescence detection of bisulfite in wines and living cells with a formyl bearing bis-cyclometalated Ir(iii) complex.

A new photoluminescence (PL) probe based on a formyl bearing bis-cyclometalated Ir(iii) complex, [Ir(ppy)(2)phen-CHO]+PF6- (1), is synthesized and applied to the selective detection of a bisulfite anion (HSO3-). Probe 1 is prepared using 2-phenylpyridine (ppy) as the C<^>N main ligand and 1,10-phenanthroline-5-carboxaldehyde (phen-CHO) as the N<^>N ancillary ligand. Probe 1 displayed excellent selective PL enhancement in response to HSO3- in acetic acid-sodium acetate buffer solution (pH = 5.0). The increase of PL signal is directly proportional to the concentration of HSO3- in the range of 2 M to 45 M with a detection limit of 0.9 M using 50 M probe 1 and in the range of 0.5 M to 6 M with a detection limit of 0.3 M using 10 M probe 1. More importantly, probe 1 can respond to HSO3- rapidly within 40 s. Furthermore, probe 1 was successfully applied to detect HSO3- in real white wines and the bioimaging of HSO3- in living cells. The superior properties of probe 1 make it of great potential use for studying the effects of HSO3- in other biosystems.