College of Chemistry, Jilin University, Changchun, 130012, People's Republic of China.
College of Medical Engineering, Jining Medical University, Jining, 272067, People's Republic of China.
Mikrochim Acta. 2019 May 3;186(6):327. doi: 10.1007/s00604-019-3438-1.
A turn-on fluorometric method is described for selective and sensitive detection of cysteine (Cys). Gold nanoclusters (Au NCs) capped with glutathione (GSH) are used as a fluorescent probe. If Ce ion are present, they will bind to the carboxy groups of the GSH-capped Au NC. This results in aggregation-induced emission enhancement (AIEE), best measured at excitation/emission wavelengths of 360/575 nm. On addition of Cys, which has less steric hindrance compared with GSH and higher affinity for Ce, it will bind to Ce through the carboxyl group and link with Au NCs via Au-S bond. Hence, the AIEE is increased and Cys can be quantified via this effect with a linear response in the 0.4-120 μmol L Cys concentration range and a detection limit of 0.15 μmol L. Graphical abstract Schematic presentation of cysteine detection via the Ce-triggered aggregation of glutathione capped gold nanoclusters which leads to increased yellow fluorescence.
一种荧光开启方法用于选择性和灵敏检测半胱氨酸（Cys）。用谷胱甘肽（GSH）稳定的金纳米簇（Au NCs）作为荧光探针。如果存在铈离子，它们将与 GSH 封端的 Au NC 的羧基结合。这导致聚集诱导的发射增强（AIEE），最佳激发/发射波长为 360/575nm。加入半胱氨酸后，由于其空间位阻较小且与 Ce 的亲和力更高，它将通过羧基与 Ce 结合，并通过 Au-S 键与 Au NCs 连接。因此，AIEE 增加，并且可以通过这种效应定量 Cys，在 0.4-120μmol L Cys 浓度范围内呈现线性响应，检测限为 0.15μmol L。
