College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, Nanshan District Key Lab for Biopolymers and Safety Evaluation, Shenzhen University, Shenzhen 518060, PR China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, PR China.
School of Atmospheric Physics, Nanjing University of Information Science & Technology, Nanjing 210044, PR China.
Talanta. 2018 Aug 15;186:110-118. doi: 10.1016/j.talanta.2018.04.044. Epub 2018 Apr 17.
Development of thiol-specific fluorescent probes with selectivity in different thiol compounds is more practical and significant than those without that capacity. In this work, a new quinoline-derived fluorophore, hydroxyl-substituted quinoline-benzo[d]oxazole 6 with high fluorescence quantum yield is synthesized and esterified with acrylic acid to afford two fluorescent probes, BQA-1 and BQA-2 for selectively discriminating Cys from Hcys/GSH based on conjugate addition-cyclization mechanism. BQA-1 exhibits a large ratiometric fluorescence response toward Cys in aqueous pH 7.4 solution with big emission peak-shifting from 383 nm to 518 nm, over 130 nm. The detection limit is determined to be as low as 0.59 μM. In contrast to BQA-1, BQA-2 whose acrylic ester moiety is further modified with pyridine group, displays a turn-on fluorescence response to Cys with detection limit of 0.98 μM. Both BQA-1 and BQA-2 have relatively weak response to another two biothiols, Hcys and GSH and nearly no response to other nucleophiles. Furthermore, the potential application for the detection of biothiols in living cells has been demonstrated by cell imaging experiment.
开发对不同硫醇化合物具有选择性的硫醇特异性荧光探针比那些没有这种能力的探针更具实际意义和重要性。在这项工作中，合成了一种具有高荧光量子产率的新的喹啉衍生荧光团，羟基取代的喹啉-苯并[d]恶唑 6，并将其与丙烯酸酯化，得到了两种荧光探针 BQA-1 和 BQA-2，它们基于共轭加成-环化机制选择性地区分 Cys 与 Hcys/GSH。BQA-1 在水相 pH 7.4 溶液中对 Cys 表现出大的比率荧光响应，发射峰从 383nm 移动到 518nm，超过 130nm。检测限低至 0.59µM。与 BQA-1 相比，BQA-2 的丙烯酸酯部分进一步用吡啶基修饰，对 Cys 显示出开启型荧光响应，检测限为 0.98µM。BQA-1 和 BQA-2 对另外两种生物硫醇 Hcys 和 GSH 的响应都相对较弱，对其他亲核试剂几乎没有响应。此外，通过细胞成像实验证明了它们在活细胞中检测生物硫醇的潜在应用。
