Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland and ‡School of Chemistry and Chemical Engineering, Yancheng Institute of Technology , Yancheng 224051, China.
Langmuir. 2017 Dec 26;33(51):14643-14648. doi: 10.1021/acs.langmuir.7b02614. Epub 2017 Dec 12.
Ratiometric fluorescent sensors have emerged as an attractive tool for analytical sensing and optical imaging due to their providing a built-in self-calibration for environmental effects. However, cumbersome processes of nanoparticles modified with fluorophores for constructing traditional ratiometric sensors limit their further application. Herein, we report a facile and label-free strategy for constructing a ratiometric sensor based on an aggregation-induced-emission (AIE)-active amine-terminated small molecule on the surface of gold nanoclusters (AuNCs). Intrinsic fluorescence of the terminal primary amine of the small molecule lysine resulting from AIE was first observed in the presence of glutathione-stabilized gold nanoclusters (GSH-AuNCs). Using lysine as both the fluorophore and the analyte, the synthesized GSH-AuNCs showed a good lysine-responsive ratiometric property. The AIE-active dual-emitting fluorescence property of the GSH-AuNCs/lysine complex made it feasible to achieve ratiometrically detection of the analyte without conjugated fluorogen. This AIE-active GSH-AuNC-based biosensor possesses high selectivity, rapid response, and excellent photostability. Moreover, the strategy opens a new pathway for the construction of a label-free ratiometric fluorescent sensor with various applications.
比率型荧光传感器由于能够为环境效应提供内置的自校准功能，因此成为分析传感和光学成像的一种有吸引力的工具。然而，传统比率型传感器中用荧光团修饰纳米粒子的繁琐过程限制了其进一步的应用。在此，我们报告了一种基于金纳米簇（AuNCs）表面的聚集诱导发射（AIE）活性末端伯胺的小分子构建比率型传感器的简便且无需标记的策略。首先观察到小分子赖氨酸末端伯胺的固有荧光在谷胱甘肽稳定的金纳米簇（GSH-AuNCs）存在下发生 AIE。使用赖氨酸作为荧光团和分析物，合成的 GSH-AuNCs 表现出良好的赖氨酸响应的比率特性。GSH-AuNCs/赖氨酸复合物的 AIE 活性双发射荧光性质使得无需共轭荧光团即可实现对分析物的比率检测成为可能。这种基于 AIE 活性的 GSH-AuNC 的生物传感器具有高选择性、快速响应和出色的光稳定性。此外，该策略为构建具有各种应用的无标记比率荧光传感器开辟了新途径。
