title: A logic gate-based fluorogenic probe for Hg(2+) detection and its applications in cellular imaging.
abstract: A new colorimetric and fluorogenic probe (RN3) based on rhodamine-B has been successfully designed and synthesized. It displays a selective response to Hg(2+) in the aqueous buffer solution over the other competing metals. Upon addition of Hg(2+), the solution of RN3 exhibits a 'naked eye' observable color change from colorless to red and an intensive fluorescence with about 105-fold enhancement. The changes in the color and fluorescence are ascribed to the ring-opening of spirolactam in rhodamine fluorophore, which is induced by a binding of the constructed receptor to Hg(2+) with the association and dissociation constants of 0.22 × 10(5) M(-1) and 25.2 μM, respectively. The Job's plot experiment determines a 1:1 binding stoichiometry between RN3 and Hg(2+). The resultant "turn-on" fluorescence in buffer solution, allows the application of a method to determine Hg(2+) levels in the range of 4.0-15.0 μM, with the limit of detection (LOD) calculated at 60.7 nM (3σ/slope). In addition, the fluorescence 'turn-off' and color 'fading-out' happen to the mixture of RN3-Hg(2+) by further addition of I(-) or S(2-). The reversible switching cycles of fluorescence intensity upon alternate additions of Hg(2+) and S(2-) demonstrate that RN3 can perform as an INHIBIT logic gate. Furthermore, the potential of RN3 as a fluorescent probe has been demonstrated for cellular imaging.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China; Division of Molecular Surface Physics & Nanoscience, Department of Physics, Chemistry and Biology, Linköping University, Linköping, 58183, Sweden.
authors.forename: Jiwen
authors.initials: J
authors.lastname: Hu
authors.affiliation: Division of Molecular Surface Physics & Nanoscience, Department of Physics, Chemistry and Biology, Linköping University, Linköping, 58183, Sweden; School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, PR China. Electronic address: zhahu@ifm.liu.se.
authors.forename: Zhangjun
authors.initials: Z
authors.lastname: Hu
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, PR China.
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China. Electronic address: hwgao@tongji.edu.cn.
authors.forename: Hong-Wen
authors.initials: HW
authors.lastname: Gao
authors.affiliation: Division of Molecular Surface Physics & Nanoscience, Department of Physics, Chemistry and Biology, Linköping University, Linköping, 58183, Sweden.
authors.forename: Kajsa
authors.initials: K
authors.lastname: Uvdal
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D003124:Colorimetry; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D008128:Logic; D008628:Mercury / Q000032:analysis*; D057054:Molecular Imaging / Q000379:methods*; D015394:Molecular Structure; D012235:Rhodamines / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D012235:Rhodamines; D008628:Mercury; C029773:rhodamine B
keywords: Fluorescent imaging; Fluorogenic probe; Logical gate; Mercury; Rhodamine