College of Chemistry and Chemical Engineering, Xinyang Key Laboratory of Functional Nanomaterials for Bioanalysis, Institute for Conservation and Utilization of Agro-bioresources in Dabie Mountains, Henan Province Key Laboratory of Utilization of Non-metallic Mineral in the South of Henan, Xinyang Normal University, Xinyang 464000, PR China.
College of Chemistry and Chemical Engineering, Xinyang Key Laboratory of Functional Nanomaterials for Bioanalysis, Institute for Conservation and Utilization of Agro-bioresources in Dabie Mountains, Henan Province Key Laboratory of Utilization of Non-metallic Mineral in the South of Henan, Xinyang Normal University, Xinyang 464000, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Dec 15;283:121724. doi: 10.1016/j.saa.2022.121724. Epub 2022 Aug 6.
Glutathione (GSH)-switched fluorescent assays have appealed much attention due to rapid signal changes of fluorescent probes. However, exposure to exterior environment of fluorescent probe causes photobleaching and premature leakage, leading to low sensitivity and poor photostability. Herein, luminescent SiO nanoparticles encapsulated with Ru(bpy) (Ru@SiO) were designed and synthesized as fluorescent probe to construct a GSH-switched fluorescent assay. The encapsulation of Ru(bpy) in the SiO nanoparticles could effectively prevent the leakage of Ru(bpy) molecules, improving the photostability of probe. The fluorescence of Ru@SiO nanoparticles was quenched by coating MnO nanoparticles on Ru@SiO surface (Ru@SiO@MnO nanocomposites) through an in situ growth approach, which reduced background of the assay. The MnO nanoparticles not only further inhibited the leakage of Ru(bpy) molecules, but also could serve as a recognition unit of GSH. In the presence of GSH, the MnO nanoparticles on the surface of Ru@SiO nanoparticles were reduced to Mn, resulting the fluorescence recovery of Ru@SiO nanoparticles. Thus, a signal-on fluorescent strategy was constructed for GSH detection. The assay displayed good analytical performance for GSH detection with a low detection limit of 16.2 nM due to excellent fluorescence quenching ability of MnO nanoparticles and special role of Ru@SiO nanoparticles to block probe leakage. The proposed assay was also applied to measure GSH levels in human serum samples. This work paves a new way to detect GSH with high sensitivity.
谷胱甘肽（GSH）切换荧光分析因其荧光探针信号变化迅速而备受关注。然而，荧光探针对外界环境的暴露会导致荧光猝灭和过早泄漏，从而导致灵敏度低和光稳定性差。本文设计并合成了包裹 Ru(bpy) 的发光 SiO 纳米粒子（Ru@SiO）作为荧光探针，构建了 GSH 切换荧光分析。将 Ru(bpy) 包裹在 SiO 纳米粒子中可以有效防止 Ru(bpy)分子的泄漏，提高探针的光稳定性。通过原位生长的方法在 Ru@SiO 表面包覆 MnO 纳米粒子（Ru@SiO@MnO 纳米复合材料），可以猝灭 Ru@SiO 纳米粒子的荧光，降低分析的背景。MnO 纳米粒子不仅进一步抑制了 Ru(bpy)分子的泄漏，而且可以作为 GSH 的识别单元。在 GSH 的存在下，Ru@SiO 纳米粒子表面的 MnO 纳米粒子被还原为 Mn，从而使 Ru@SiO 纳米粒子的荧光恢复。因此，构建了一种信号开启型荧光策略用于 GSH 的检测。由于 MnO 纳米粒子具有优异的荧光猝灭能力和 Ru@SiO 纳米粒子对探针泄漏的特殊阻断作用，该分析方法对 GSH 的检测具有良好的分析性能，检测限低至 16.2 nM。该方法还用于测定人血清样品中的 GSH 水平。这项工作为高灵敏度检测 GSH 开辟了一条新途径。
