We demonstrate stimulated emission depletion (STED) microscopy with 20 nm gold nanospheres coated by fluorescently doped silica. We demonstrate significantly improved spatial resolution down to 75 nm, which is the first time that hybrid NPs are used in STED imaging beyond the diffraction limit of confocal microscopy. Unlike previous demonstrations of super-resolution with metal nanoparticles with different techniques, this 3.3-fold resolution improvement was limited only by the particle size. The STED intensity required for this is almost twice lower than for conventional STED based on dye alone, and we observe no melting or displacement of the NPs at the utilized intensities. Moreover, we show that the nanoparticles can be imaged in an aqueous environment, demonstrating the relevance to bioimaging. Finally, we also show, for the first time in this context, an up to 3-fold reduction in the rate of photobleaching compared to standard dye-based STED, thus enabling sustainably brighter images.

中文翻译：

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纳米金纳米球辅助的STED纳米技术

我们展示了由荧光掺杂的二氧化硅涂覆的20 nm金纳米球的激发发射耗尽（STED）显微镜。我们证明了低至75 nm的空间分辨率有了显着提高，这是混合NP在STED成像中首次超过共聚焦显微镜的衍射极限。与先前使用不同技术对金属纳米粒子进行超分辨率的演示不同，这种3.3倍的分辨率提高仅受粒度限制。为此所需的STED强度几乎比仅基于染料的常规STED降低了两倍，并且在所使用的强度下，我们未观察到NP的熔化或位移。此外，我们表明纳米粒子可以在水性环境中成像，证明了与生物成像的相关性。最后，我们还展示了