We have developed a highly sensitive and reliable fluorescence resonance energy transfer (FRET) probe using nitro-dopamine (ND) and dopamine (DA) coated MnO₂ nanosheet (ND@MnO₂ NS and DA@MnO₂ NS) as an energy acceptor and MoS₂ quantum dots (QDs) as an energy donor. By employing surface-modified MnO₂ NS, we can effectively reduce the fluorescence intensity of MoS₂ QDs through FRET. It can reduce MnO₂ NS to Mn²⁺ and facilitate the fluorescence recovery of the MoS₂ QDs. This ND@MnO₂ NS@MoS₂ QD-based nanoprobe demonstrates excellent sensitivity to GSH, achieving an LOD of 22.7 nM in an aqueous medium while exhibiting minimal cytotoxicity and good biocompatibility. Moreover, our sensing platform shows high selectivity to GSH towards various common biomolecules and electrolytes. Confocal fluorescence imaging revealed that the nanoprobe can image GSH in A549 cells. Interestingly, the ND@MnO₂ NS nanoprobe demonstrates no cytotoxicity in living cancer cells, even at concentrations up to 100 μg mL⁻¹. Moreover, the easy fabrication and eco-friendliness of ND@MnO₂ NS make it a rapid and simple method for detecting GSH. We envision the developed nanoprobe as an incredible platform for real-time monitoring of GSH levels in both extracellular and intracellular mediums, proving valuable for biomedical research and clinical diagnostics.

中文翻译：

---

硝基多巴胺修饰的 MnO2 NS-MoS2QDs 杂化纳米复合材料用于细胞外和细胞内谷胱甘肽的检测

我们开发了一种高度灵敏且可靠的荧光共振能量转移（FRET）探针，使用硝基多巴胺（ND）和多巴胺（DA）涂覆的MnO ₂纳米片（ND@MnO ₂ NS和DA@MnO ₂ NS）作为能量受体和MoS ₂量子点（QD）作为能量供体。通过采用表面修饰的MnO _{2 NS，我们可以通过FRET有效降低MoS 2} QD的荧光强度。它可以将MnO ₂ NS还原为Mn ^{2+并促进MoS} ₂ QD的荧光恢复。这种基于 ND@MnO ₂ NS@MoS ₂ QD 的纳米探针对 GSH 具有出色的灵敏度，在水介质中达到 22.7 nM 的 LOD，同时表现出最小的细胞毒性和良好的生物相容性。此外，我们的传感平台对 GSH 对各种常见生物分子和电解质表现出高选择性。共焦荧光成像显示纳米探针可以对 A549 细胞中的 GSH 进行成像。有趣的是，ND@MnO ₂ NS纳米探针在活癌细胞中没有表现出细胞毒性，即使浓度高达100 μg mL ^-1。此外，ND@MnO ₂ NS易于制造且环保，使其成为一种快速、简单的 GSH 检测方法。我们设想开发的纳米探针作为一个令人难以置信的平台，用于实时监测细胞外和细胞内介质中的谷胱甘肽水平，这对生物医学研究和临床诊断具有重要价值。