Zhang Xuan, Zhang Li, Ma Wei-Wei, Zhou Yong, Lu Zhen-Ni, Xu Suying
Key Laboratory of Science and Technology of Eco-Textiles, Ministry of Education, College of Chemistry, Chemical Engineering & Biotechnology, Donghua University, Shanghai, China.
State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, China.
Front Chem. 2019 Feb 1;7:32. doi: 10.3389/fchem.2019.00032. eCollection 2019.
A benzothiazole-based near-infrared (NIR) ratiometric fluorescent probe () was developed for discriminating cysteine (Cys) from homocysteine (Hcy) and glutathione (GSH). The probe was designed by masking phenol group in the conjugated benzothiazole derivative with methacrylate group that could be selectively removed by Cys, and therefore an intramolecular charge transfer (ICT) fluorescence was switched on in the NIR region. In the absence of Cys, the probe exhibited a strong blue fluorescence emission at 431 nm, whereas a NIR fluorescence emission at 710 nm was significantly enhanced accompanied by a decrease of emission at 431 nm in the presence of Cys, allowing a ratiometric fluorescence detection of Cys. The fluorescence intensity ratio (I/I) showed a good linear relationship with Cys concentration of 1-40 μM with the detection limit of 0.5 μM. The sensing mechanism was explored based on MS experimental analysis and DFT theoretical calculation. Moreover, the fluorescent probe was successfully used for fluorescence bioimaging of Cys in living cells.
开发了一种基于苯并噻唑的近红外（NIR）比率荧光探针（），用于区分半胱氨酸（Cys）与同型半胱氨酸（Hcy）和谷胱甘肽（GSH）。该探针是通过用甲基丙烯酸酯基团掩盖共轭苯并噻唑衍生物中的酚基团来设计的，甲基丙烯酸酯基团可被Cys选择性去除，因此在近红外区域开启了分子内电荷转移（ICT）荧光。在没有Cys的情况下，探针在431 nm处表现出强烈的蓝色荧光发射，而在存在Cys的情况下，710 nm处的近红外荧光发射显著增强，同时431 nm处的发射减弱，从而实现了对Cys的比率荧光检测。荧光强度比（I/I）与1-40 μM的Cys浓度呈现良好的线性关系，检测限为0.5 μM。基于质谱实验分析和密度泛函理论计算探索了传感机制。此外，该荧光探针成功用于活细胞中Cys的荧光生物成像。
