Premium
Rational Design of an Ultrasensitive and Highly Selective Chemodosimeter by a Dual Quenching Mechanism for Cysteine Based on a Facile Michael‐Transcyclization Cascade Reaction
Author(s) -
Li Xiangmin,
Zheng Yongjun,
Tong Hongjuan,
Qian Rui,
Zhou Lin,
Liu Guixia,
Tang Yun,
Li Hao,
Lou Kaiyan,
Wang Wei
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201601126
Subject(s) - michael reaction , chemistry , fluorophore , cysteine , maleimide , glutathione , fluorescence , intramolecular force , thiol , photochemistry , combinatorial chemistry , adduct , quenching (fluorescence) , photoinduced electron transfer , cascade reaction , electrophile , selectivity , electron transfer , stereochemistry , organic chemistry , physics , quantum mechanics , enzyme , catalysis
Differentiation of biologically important thiols, such as cysteine (Cys), homocysteine (Hcy), and glutathione (GSH) is still a challenging task. Herein, we present a novel fluorescent chemodosimeter capable of selectively detecting Cys over other biothiols including Hcy and GSH and other amino acids by a facile thiol‐Michael addition/transcyclization rearrangement cascade click process. The unique transcyclization step is critical for the selectivity as a result of the kinetically favorable formation of a six‐membered ring with the Cys Michael adduct. Moreover, the probe adopts a distinctive dual quenching mechanism—photoinduced electron transfer (PET) and photoinduced intramolecular charge transfer (ICT) to deliver a drastic turn‐on fluorescence response only at the Cys‐selective transcylization step. The judicious selection of strong electron‐withdrawing naphthalimide fluorophore with maleimide group enhances the electrophilicity and thus reactivity for the cascade process leading to fast detection and ultrasensitivity with a detection limit of 2.0 n m ( S / N =3). The probe has demonstrated its practical utility potential in Cys imaging in live cells.