A Naphthalimide–Sulfonylhydrazine Conjugate as a Fluorescent Chemodosimeter for Hypochlorite
Yasuhiro Shiraishi,
Rikako Nakatani,
Shunsuke Takagi,
Chiharu Yamada,
Takayuki Hirai
Affiliations
Yasuhiro Shiraishi
Research Center for Solar Energy Chemistry, and Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
Rikako Nakatani
Research Center for Solar Energy Chemistry, and Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
Shunsuke Takagi
Research Center for Solar Energy Chemistry, and Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
Chiharu Yamada
Research Center for Solar Energy Chemistry, and Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
Takayuki Hirai
Research Center for Solar Energy Chemistry, and Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
Hypochlorite anion (ClO−) is a widely-used disinfectant and a microbicidal agent in the immune system. Accurate detection of ClO− in environmental and biological samples by simply prepared chemosensors/chemodosimeters is important. Herein, we report that a naphthalimide–sulfonylhydrazine conjugate with an imine (C=N) linker, prepared via simple condensation, acts as an effective fluorescent chemodosimeter for ClO−. The molecule exhibits a weak emission, but ClO−-selective cleavage of its C=N bond creates a strong green emission. Ab initio calculation showed that the emission enhancement by ClO− originates from the suppression of intramolecular electron transfer from the photoexcited naphthalimide through the C=N linker. This response enables selective and sensitive detection of ClO− at physiological pH range (7–9) and allows fluorometric ClO− imaging in the presence of cells.
