title: Multi-channel colorimetric and fluorescent probes for differentiating between cysteine and glutathione/homocysteine.
abstract: Three fluorescent probes TP1–3 for thiols were rationally designed and synthesized to distinguish cysteine (Cys) from glutathione (GSH)/homocysteine (Hcy). TP1–3 are almost non-fluorescent and colorless 4-nitro-1,8-naphthalimide derivatives. Upon the substitution of nitro by Cys, TP1–3 were transformed into weakly fluorescent green-emitting 4-amino analogs via highly fluorescent blue-emitting thioether intermediates. The three-channel signaling capability allows discrimination between Cys and GSH/Hcy. The fluorescence intensity at 498 nm was linearly proportional to GSH concentration in the range of 0-20 μM, and the detection limit was 5 × 10(-8) mol L(-1). A good linear relationship between A446/A350 and Cys concentration was found in the range of 0-70 μM, and the detection limit was 2 × 10(-7) mol L(-1). Moreover, TP3 was used for living cell imaging as well as for detecting mercapto-containing proteins.
authors.affiliation: Shanghai Key Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, China. junhongqian@ecust.edu.cn weibingzhang@ecust.edu.cn.
authors.forename: Lun
authors.initials: L
authors.lastname: Song
authors.forename: Ti
authors.initials: T
authors.lastname: Jia
authors.forename: Wenjia
authors.initials: W
authors.lastname: Lu
authors.forename: Nengqin
authors.initials: N
authors.lastname: Jia
authors.forename: Weibing
authors.initials: W
authors.lastname: Zhang
authors.forename: Junhong
authors.initials: J
authors.lastname: Qian
mesh_terms: D002460:Cell Line; D003545:Cysteine / Q000032:analysis*; D005456:Fluorescent Dyes / Q000737:chemistry*; D005978:Glutathione / Q000032:analysis*; D006710:Homocysteine / Q000032:analysis*; D006801:Humans; D057230:Limit of Detection; D061848:Optical Imaging / Q000379:methods; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D005456:Fluorescent Dyes; D006710:Homocysteine; D005978:Glutathione; D003545:Cysteine