Video-rate super-resolution imaging through biological tissue can visualize and track biomolecule interplays and transportations inside cellular organisms. Structured illumination microscopy allows for wide-field super resolution observation of biological samples but is limited by the strong extinction of light by biological tissues, which restricts the imaging depth and degrades its imaging resolution. Here we report a photon upconversion scheme using lanthanide-doped nanoparticles for wide-field super-resolution imaging through the biological transparent window, featured by near-infrared and low-irradiance nonlinear structured illumination. We demonstrate that the 976 nm excitation and 800 nm upconverted emission can mitigate the aberration. We found that the nonlinear response of upconversion emissions from single nanoparticles can effectively generate the required high spatial frequency components in the Fourier domain. These strategies lead to a new modality in microscopy with a resolution below 131 nm, 1/7th of the excitation wavelength, and an imaging rate of 1 Hz.

中文翻译：

---

上转换非线性结构照明显微镜。

通过生物组织的视频速率超分辨率成像可以可视化并跟踪生物分子在细胞有机体内的相互作用和运输。结构照明显微镜允许对生物样品进行宽视野超分辨率观察，但受到生物组织强烈消光的限制，这限制了成像深度并降低了其成像分辨率。在这里，我们报告使用镧系元素掺杂的纳米粒子通过生物透明窗口进行宽域超分辨率成像的光子上转换方案，其特征在于近红外和低辐射非线性结构照明。我们证明了976 nm激发和800​​ nm上转换后的发射可以减轻像差。我们发现，单个纳米粒子上转换发射的非线性响应可以有效地在傅立叶域中生成所需的高空间频率分量。这些策略导致了一种新的显微镜技术，其分辨率低于131 nm，是激发波长的1/7，成像速率为1 Hz。