title: Reversible fluorescent probe for highly selective and sensitive detection of mercapto biomolecules.
abstract: A coumarin-derived complex, Hg(2)L(2), was reported as a highly sensitive and selective probe for the detection of mercapto biomolecules in aqueous solution. The addition of Cys to a 99% aqueous solution of Hg(2)L(2) resulted in rapid and remarkable fluorescence OFF-ON (emission at 525 nm) due to the ligand-exchange reaction of Cys with L coordinated to Hg(2+). The increased fluorescence can be completely quenched by Hg(2+) and recovered again by the subsequent addition of Cys. Such a fluorescence OFF-ON circle can be repeated at least 10 times by the alterative addition of Cys and Hg(2+) to the solution of Hg(2)L(2), indicating that it can be used as a convertible and reversible probe for the detection of Cys. The interconversion of Hg(2)L(2) and L via the decomplexation/complexation by the modulation of Cys/Hg(2+) was definitely verified from their crystal structures. Other competitive amino acids without a thiol group cannot induce any fluorescence changes, implying that Hg(2)L(2) can selectively determine mercapto biomolecules. Using confocal fluorescence imaging, L/Hg(2)L(2) as a pair of reversible probes can be further applied to track and monitor the self-detoxification process of Hg(2+) ions in SYS5 cells.
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Jiasheng
authors.initials: J
authors.lastname: Wu
authors.forename: Ruilong
authors.initials: R
authors.lastname: Sheng
authors.forename: Weimin
authors.initials: W
authors.lastname: Liu
authors.forename: Pengfei
authors.initials: P
authors.lastname: Wang
authors.forename: Jingjin
authors.initials: J
authors.lastname: Ma
authors.forename: Hongyan
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Zhuang
mesh_terms: D002478:Cells, Cultured; D003374:Coumarins / Q000737:chemistry; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000032:analysis*; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D005978:Glutathione / Q000032:analysis*; D057809:HEK293 Cells; D006710:Homocysteine / Q000032:analysis*; D006801:Humans; D008628:Mercury / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009941:Organomercury Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010316:Particle Size; D013237:Stereoisomerism; D013499:Surface Properties
chemical_list: D003374:Coumarins; D005456:Fluorescent Dyes; D009941:Organomercury Compounds; D006710:Homocysteine; C030123:coumarin; D008628:Mercury; D005978:Glutathione; D003545:Cysteine