title: A reversible fluorescence chemosensor for sequentially quantitative monitoring copper and sulfide in living cells.
abstract: We report a novel, selective and sensitive strategy for the sequentially "ON-OFF-ON" fluorescent detection of Cu(2+) and S(2-) based on a fluorescein derivative, FL. The specific binding of FL towards Cu(2+) in aqueous and biological media led to the intensive green fluorescence quenching and a notable increase of the absorbance maximum at 480 nm. In the presence of S(2-), the intensity and overall pattern of the fluorescence emission and UV-vis spectra of FL-Cu(2+) ensemble were recovered since the abolishment of paramagnetic Cu(2+). This displacement approach exhibited highly specificity, and sensitivity with detection limits of 3 nM for Cu(2+) and 150 nM for S(2-). The fluorescence "ON-OFF-ON" circle can be repeated to a minimum of 5 times by the alternative addition of Cu(2+) and S(2-), implying that FL is a renewable dual-functional chemosensor. The biocompatibility of FL toward breast carcinoma cells, MDA-MB-231 was confirmed by MTT assay. The reversible "ON-OFF-ON" fluorescent response of FL to Cu(2+) and S(2-) in living system was further confirmed by confocal fluorescence imaging of living cells. The quantification of Cu(2+) and S(2-) in single intact cell was realized by the flow cytometry analysis.
authors.affiliation: School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114044, China. Electronic address: qtmeng@ustl.edu.cn.
authors.forename: Qingtao
authors.initials: Q
authors.lastname: Meng
authors.affiliation: Department of Chemistry and Biomolecular Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: Run
authors.initials: R
authors.lastname: Zhang
authors.affiliation: School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114044, China.
authors.forename: Hongmin
authors.initials: H
authors.lastname: Jia
authors.affiliation: School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114044, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Gao
authors.affiliation: School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114044, China.
authors.forename: Cuiping
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Chemistry and Biomolecular Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Department of Chemistry and Biomolecular Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: Arun V
authors.initials: AV
authors.lastname: Everest-Dass
authors.affiliation: School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114044, China. Electronic address: zhangzhiqiang@ustl.edu.cn.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003300:Copper / Q000032:analysis* / Q000737:chemistry; D019793:Fluorescein / Q000737:chemistry* / Q000494:pharmacology; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry* / Q000494:pharmacology; D006801:Humans; D013050:Spectrometry, Fluorescence; D013440:Sulfides / Q000032:analysis* / Q000737:chemistry; D013881:Thioridazine / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D005456:Fluorescent Dyes; D013440:Sulfides; D003300:Copper; D013881:Thioridazine; D019793:Fluorescein
keywords: Detection; Dual-functional chemosensor; Fluorescein; Fluorescence imaging; Quantification