title: A near-infrared fluorescent probe based on chloroacetate modified naphthofluorescein for selectively detecting cysteine/homocysteine and its application in living cells.
abstract: We have prepared a near-infrared (NIR) turn-on fluorescent probe (NFC) based on chloroacetate modified naphthofluorescein for specific detection of cysteine (Cys) and homocysteine (Hcy) over glutathione (GSH) and other amino acids (AAs) with the detection limits of 0.30 μM and 0.42 μM, respectively. The fluorescence intensity of the naphthofluorescein (NF) chromophore is modulated by an internal charge transfer (ICT) process. The probe NFC is readily available and weakly fluorescent, but of observably enhanced fluorescence after reacting with Cys or Hcy. We assumed and then demonstrated that the fluorescence off-on process involves a conjugate nucleophilic substitution/cyclization sequence. Furthermore, the probe has been successfully applied for detecting the total content of Cys and Hcy in human plasma and imaging in living cells with low toxicity.
authors.affiliation: Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province and State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China. zhanghx@lzu.edu.cn.
authors.forename: Jianxi
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Cell Biology, School of Life Sciences, Lanzhou University, Lanzhou 730000, P. R. China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province and State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China. zhanghx@lzu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province and State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China. zhanghx@lzu.edu.cn.
authors.forename: Jianjian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province and State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China. zhanghx@lzu.edu.cn.
authors.forename: Xinyue
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province and State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China. zhanghx@lzu.edu.cn.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Cell Biology, School of Life Sciences, Lanzhou University, Lanzhou 730000, P. R. China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province and State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China. zhanghx@lzu.edu.cn.
authors.forename: Haixia
authors.initials: H
authors.lastname: Zhang
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods*; D002478:Cells, Cultured; D062845:Chloroacetates / Q000737:chemistry*; D003545:Cysteine / Q000097:blood / Q000378:metabolism*; D005452:Fluoresceins / Q000737:chemistry* / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006710:Homocysteine / Q000378:metabolism*; D006801:Humans; D013050:Spectrometry, Fluorescence
chemical_list: D062845:Chloroacetates; D005452:Fluoresceins; D005456:Fluorescent Dyes; C000601316:naphthofluorescein; D006710:Homocysteine; D003545:Cysteine