title: Coumarin-Based Turn-On Fluorescence Probe for Specific Detection of Glutathione over Cysteine and Homocysteine.
abstract: We have prepared a turn-on fluorescent probe for biothiols based on bromoketo coumarin (KC-Br). The emission intensity of the coumarin chromophore is modulated by both the heavy atom effect and internal charge transfer (ICT) process. The probe KC-Br is intrinsically nonfluorescent; however, after being reacted with thiols, the bromide moiety is substituted by the -SH group, which elicits a significant fluorescence increase. We surmised the free -NH2 group would further react with carbonyl in the Cys/Hcy-substituted intermediate product yielding to Schiff base compound KC-Cys/KC-Hcy, but not in compound KC-GSH. The ICT effect has a stronger influence in compound KC-GSH than that in compound KC-Cys/KC-Hcy, resulting in compound KC-GSH having a stronger fluorescence. Thus, the probe has a good selectivity for GSH over other various biologically relevant species and even two other similar biothiols (Cys/Hcy) and could image glutathione (GSH) in living cells. We expect the design concept presented in this work would be widely used for the design of fluorescent probes for distinguishing among biothiols.
authors.affiliation: ‡State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, P. R. China.
authors.forename: Longwei
authors.initials: L
authors.lastname: He
authors.affiliation: ‡State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, P. R. China.
authors.forename: Qiuyan
authors.initials: Q
authors.lastname: Xu
authors.affiliation: †Institute of Fluorescent Probes for Biological Imaging, School of Chemistry and Chemical Engineering, School of Biological Science and Technology, University of Jinan, Jinan, Shandong 250022, P.R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: ‡State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, P. R. China.
authors.forename: Haipeng
authors.initials: H
authors.lastname: Wei
authors.affiliation: †Institute of Fluorescent Probes for Biological Imaging, School of Chemistry and Chemical Engineering, School of Biological Science and Technology, University of Jinan, Jinan, Shandong 250022, P.R. China.
authors.forename: Yonghe
authors.initials: Y
authors.lastname: Tang
authors.affiliation: †Institute of Fluorescent Probes for Biological Imaging, School of Chemistry and Chemical Engineering, School of Biological Science and Technology, University of Jinan, Jinan, Shandong 250022, P.R. China.|‡State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, P. R. China.
authors.forename: Weiying
authors.initials: W
authors.lastname: Lin
mesh_terms: D003374:Coumarins / Q000737:chemistry*; D003545:Cysteine; D005456:Fluorescent Dyes / Q000737:chemistry*; D005978:Glutathione / Q000032:analysis*; D006367:HeLa Cells; D006710:Homocysteine; D006801:Humans; D006863:Hydrogen-Ion Concentration; D061848:Optical Imaging / Q000379:methods*
chemical_list: D003374:Coumarins; D005456:Fluorescent Dyes; D006710:Homocysteine; C030123:coumarin; D005978:Glutathione; D003545:Cysteine
keywords: bromoketo coumarin; fluorescence imaging; fluorescent probe; glutathione; specific detection