Open AccessRhodol Derivatives as Selective Fluorescent Probes for the Detection of Hg II Ions and the Bioimaging of Hypochlorous Acid
Author(s) -
Li Ling,
Wang Shu,
Lan Hongxia,
Gong Guiyi,
Zhu Yifan,
Tse Yu Chung,
Wong Keith ManChung
Publication year - 2018
Publication title -
chemistryopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 29
ISSN - 2191-1363
DOI - 10.1002/open.201700154
Subject(s) - chemistry , moiety , hypochlorous acid , fluorescence , hypochlorite , rhodamine , isothiocyanate , photochemistry , absorption (acoustics) , selectivity , surface modification , analyte , inorganic chemistry , organic chemistry , chromatography , materials science , physics , quantum mechanics , composite material , catalysis
Two sensors, 1 with a spirolactone group and 2 with a spirolactam group containing a phenyl isothiocyanate moiety, based on rhodol, were designed and synthesized in order to obtain materials with excellent optical properties for the detection of environmentally and biologically important Hg 2+ and hypochlorous acid (HClO) ions. The crystal structure of 1 revealed two moieties, a rhodamine‐like portion with a spirolactone and a fluorescein‐like portion without a spirolactone. In the absence of analyte, 1 produced an optical output with a maximum absorption and emission at 475 and 570 nm, respectively, which was attributed to the fluorescein‐like moiety without a spirolactone. In contrast, the rhodamine‐like moiety containing a spirolactone was activated by the addition of H + or Hg 2+ ions, and 1 yielded new absorption and emission peaks at 530 and 612 nm, respectively. Further functionalization with a phenyl isothiocyanate group afforded 2 , a fluorescent probe for HClO. High selectivity and sensitivity towards the hypochlorite ion were anticipated, owing to the stoichiometric and irreversible formation of a thiosemicarbazide group, which led to dramatic fluorescence responses. With good functionality at physiological pH, probe 2 was successfully used to image HClO in HeLa cells.