Biocompatible carbon dots with low-saturation-intensity and high-photobleaching-resistance for STED nanoscopy imaging of the nucleolus and tunneling nanotubes in living cells
Biocompatible carbon dots with low-saturation-intensity and high-photobleaching-resistance for STED nanoscopy imaging of the nucleolus and tunneling nanotubes in living cells
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DOI：
10.1007/s12274-019-2554-x
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发表时间：
2019-11-13
期刊：
影响因子：
9.9
通讯作者：
Qu, Junle
中科院分区：
文献类型：
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作者：
Li, Hao;Ye, Shuai;Qu, Junle
多种纳米粒子和有机染料作为荧光探针已被应用于受激发射耗尽（STED）纳米显微技术中。由于这些荧光探针的高毒性、光致漂白和非水溶性，很难应用于活细胞成像。本文报道了一种新型的荧光碳点（FNCDs），通过掺杂氟元素，可获得光致发光量子产率高（56%）、毒性低、抗光漂白、水溶性好的荧光碳点，适合于活细胞成像。此外，FNCDs可以染色活细胞中的核仁和隧道纳米管（TNT）。更重要的是，对于STED纳米成像，FNCD有效地耗尽了背景信号并提高了成像分辨率。此外，在STED纳米显微镜下，获得了沉积在载玻片上的单个FNCD尺寸的横向分辨率高达22.1 nm。由于其良好的亲水性，活细胞核仁中单个FNCDs的分辨率可达19.7nm。在图像优化步骤之后，获得了具有约100 μ m直径的TNTs的精细荧光图像。活细胞成像的分辨率可达75 nm，比共聚焦成像提高了3倍。此外，在STED模型中，FNCD在1，000次扫描循环后显示出优异的耐光漂白性。所有结果表明，FNCDs在STED纳米显微镜中具有显著的应用潜力。
Many kinds of nanoparticles and organic dyes as fluorescent probes have been used in the stimulated emission depletion (STED) nanoscopy. Due to high toxicity, photobleaching and non-water solubility, these fluorescent probes are hard to apply in living cell imaging. Here, we report a new fluorescence carbon dots (FNCDs) with high photoluminescence quantum yield (56%), low toxicity, anti-photobleaching and good water-solubility that suitable for live-cell imaging can be obtained by doping fluorine element. Moreover, the FNCDs can stain the nucleolus and tunneling nanotubes (TNTs) in the living cell. More importantly, for STED nanoscopy imaging, the FNCDs effectively depleted background signals and improved imaging resolution. Furthermore, the lateral resolution of single FNCDs size under the STED nanoscopy is up to 22.1 nm for FNCDs deposited on a glass slide was obtained. And because of their good water dispersibility, the higher resolution of single FNCDs size in the nucleolus of a living cell can be up to 19.7 nm. After the image optimization steps, the fine fluorescence images of TNTs diameter with ca. 75 nm resolution is obtained living cell, yielding a threefold enhancement compared with that in confocal imaging. Additionally, the FNCDs show excellent photobleaching resistance after 1,000 scan cycles in the STED model. All results show that FNCDs have significant potential for application in STED nanoscopy.