In view of the vital role of biothiols in many physiological processes, the development of simple and efficient probe for the detection of biothiols is of great medical significance. In this work, we demonstrate the use of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), which respond rapidly to biothiols especially to glutathione, as a new fluorescent probe for the selective detection and bioimaging of biothiols. This new fluorescent probe can distinguish glutathione from cysteine and homocysteine easily under physiological concentration and detect glutathione quickly within three minutes. This probe exhibits high selectivity to biothiols and the detection limit was determined to be 3.08 × 10⁻⁹ M for glutathione, 8.55 × 10⁻⁸ M for cysteine, and 2.17 × 10⁻⁹ M for homocysteine, respectively. The sensing mechanism was further explored by density functional theory (DFT) and nuclear magnetic resonance (NMR) experiment; results showed that the interaction forces between the probe and biothiols were electrostatic interaction. In addition, the probe has been successfully applied to the detection of biothiols in Eca9706 cells by fluorescence confocal imaging technology.

中文翻译：

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一种新的基于醌的荧光探针，可高灵敏度和选择性地检测生物硫醇及其在活细胞成像中的应用。

鉴于生物硫醇在许多生理过程中的重要作用，开发简单高效的生物硫醇检测探针具有重要的医学意义。在这项工作中，我们展示了对生物硫醇（尤其是谷胱甘肽）快速反应的2,3-二氯-5,6-二氰基-1,4-苯醌（DDQ）的使用，作为选择性检测和生物成像的新型荧光探针生物硫醇。这种新型荧光探针可以在生理浓度下轻松将谷胱甘肽与半胱氨酸和高半胱氨酸区分开，并在三分钟内快速检测出谷胱甘肽。该探针对生物硫醇具有很高的选择性，对谷胱甘肽的检出限确定为3.08×10 ^-9  M， 对半胱氨酸的检出限为8.55×10 ^-8 M，以及2.17×10 ^-9 M分别代表同型半胱氨酸。通过密度泛函理论（DFT）和核磁共振（NMR）实验进一步探索了这种传感机制。结果表明，探针与生物硫醇的相互作用力为静电相互作用。此外，该探针已通过荧光共聚焦成像技术成功应用于Eca9706细胞中生物硫醇的检测。