Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
ACS Appl Mater Interfaces. 2021 Mar 3;13(8):9359-9368. doi: 10.1021/acsami.0c15543. Epub 2020 Nov 10.
Here, fluorescent molecular rotors are employed to develop a new type of high-performance FRET system with large Stokes shift, high photostability, and pH insensitivity, showing great promise for use in proximity-dependent DNA aptasensors. Two carboxylated benzothiazole-based molecular rotors are synthesized, displaying bright green and red fluorescence once labeled to DNA. In the proximity state, an efficient FRET occurs between the two dyes, comparable to that of the most commonly used Cy3/Cy5 pair. Similar phenomena are also observed if naphthothiazole-based analogues are adopted. Our developed FRET pair is then attached to the two parts of a split ATP aptamer in a dimeric DNA nanoscaffold controlled by a bimolecular i-motif. In this way, a pH-switched proximity-induced fluorescent ATP aptasensor is constructed, with good sensitivity, selectivity, and reconfiguration. Furthermore, by altering the linker length of the switching unit, the proximity effect is investigated systematically, providing new insight into DNA proximity reactions and their roles in some physiological processes.
在这里，荧光分子转子被用于开发一种具有大斯托克斯位移、高光稳定性和 pH 不敏感性的新型高性能 FRET 系统，有望用于基于邻近依赖的 DNA 适体传感器。合成了两种基于羧基苯并噻唑的分子转子，一旦标记到 DNA 上，就会显示出明亮的绿色和红色荧光。在邻近状态下，两种染料之间发生有效的 FRET，与最常用的 Cy3/Cy5 对相当。如果采用基于萘并噻唑的类似物，也会观察到类似的现象。然后，我们开发的 FRET 对被连接到双分子 i-motif 控制的二聚体 DNA 纳米支架中分裂的 ATP 适体的两个部分上。通过这种方式，构建了一种 pH 切换的邻近诱导荧光 ATP 适体传感器，具有良好的灵敏度、选择性和重构性。此外，通过改变开关单元的连接体长度，系统地研究了邻近效应，为 DNA 邻近反应及其在一些生理过程中的作用提供了新的见解。
