An Aldol Reaction-Based Iridium(III) Chemosensor for the Visualization of Proline in Living Cells.
A long-lived aldol reaction-based iridium(III) chemosensor [Ir(ppy)2(5-CHOphen)]PF6(1, where ppy = 2-phenylpyridine and 5-CHOphen = 1,10-phenanthroline-5-carbaldehyde) for proline detection has been synthesized. The iridium(III) complex 1, incorporating an aldehyde group in N^N donor ligand, can take part in aldol reaction with acetone mediated by proline. The transformation of the sp2-hybridized carbonyl group into a sp3-hybridized alcohol group influences the metal-to-ligand charge-transfer (MLCT) state of the iridium(III) complex, resulting in a change in luminescence in response to proline. The interaction of the iridium(III) complex 1 with proline was investigated by1H NMR, HRMS and emission titration experiments. Upon the addition of proline to a solution of iridium(III) complex 1, a maximum 8-fold luminescence enhancement was observed. The luminescence signal of iridium(III) complex 1 could be recognized in strongly fluorescent media using time-resolved emission spectroscopy (TRES). The detection of proline in living cells was also demonstrated.
Department of Chemistry, Jiangxi University of Science and Technology, Ganzhou, China.|Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
Jin-Biao
JB
Liu
State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
Li-Juan
LJ
Liu
Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
Zhen-Zhen
ZZ
Dong
State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
Guan-Jun
GJ
Yang
State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
Chung-Hang
CH
Leung
Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
Dik-Lung
DL
Ma
D045744:Cell Line, Tumor; D006801:Humans; D007495:Iridium / Q000378:metabolism*; D008024:Ligands; D049449:Luminescence; D010618:Phenanthrolines / Q000378:metabolism; D011392:Proline / Q000378:metabolism*; D011725:Pyridines / Q000378:metabolism
D008024:Ligands; D010618:Phenanthrolines; D011725:Pyridines; C058324:2-phenylpyridine; D007495:Iridium; D011392:Proline; C025205:1,10-phenanthroline