Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing, Jiangsu 210093, China.
School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing, Jiangsu 210093, China.
Analyst. 2018 Feb 7;143(3):741-746. doi: 10.1039/c7an01710c. Epub 2018 Jan 11.
By combining leucine (Leu) and tetraphenylethene (TPE), a pH-sensitive aggregation induced emission (AIE) probe TPE-Leu was developed. The aliphatic amine in TPE-Leu was more easily protonated under acidic conditions, which made TPE-Leu more water soluble. Therefore, the protonated AIE probe showed weak fluorescence under acidic conditions. When the pH was changed to basic conditions, it showed strong fluorescence due to the hydrophobic nature of TPE-Leu. We demonstrated that the probe showed high selectivity toward pH changes with the coexistence of other potential species such as metal ions, redox agents, and biomolecules. In contrast, TPE-NH did not exhibit obvious pH-sensitive properties. Moreover, TPE-Leu was further utilized to develop a sensitive and selective sensing platform for urease and acetylcholinesterase (AChE) detection. The current study not only provides a new strategy for designing pH-sensitive fluorescent probes for bioassays but also broadens the applications of AIE probes.
通过将亮氨酸（Leu）和四苯乙烯（TPE）结合，开发了一种对 pH 敏感的聚集诱导发射（AIE）探针 TPE-Leu。TPE-Leu 中的脂肪胺在酸性条件下更容易质子化，这使得 TPE-Leu 更具水溶性。因此，质子化的 AIE 探针在酸性条件下显示出较弱的荧光。当 pH 变为碱性条件时，由于 TPE-Leu 的疏水性，它显示出强荧光。我们证明，探针在存在其他潜在物质（如金属离子、氧化还原试剂和生物分子）的情况下，对 pH 变化具有高选择性。相比之下，TPE-NH 没有表现出明显的 pH 敏感特性。此外，TPE-Leu 进一步用于开发用于检测脲酶和乙酰胆碱酯酶（AChE）的灵敏和选择性传感平台。本研究不仅为生物分析设计 pH 敏感荧光探针提供了新策略，而且拓宽了 AIE 探针的应用。
