National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK.
Nat Commun. 2022 Aug 15;13(1):4787. doi: 10.1038/s41467-022-32548-x.
Three dimensional scaffolded DNA origami with inorganic nanoparticles has been used to create tailored multidimensional nanostructures. However, the image contrast of DNA is poorer than those of the heavy nanoparticles in conventional transmission electron microscopy at high defocus so that the biological and non-biological components in 3D scaffolds cannot be simultaneously resolved using tomography of samples in a native state. We demonstrate the use of electron ptychography to recover high contrast phase information from all components in a DNA origami scaffold without staining. We further quantitatively evaluate the enhancement of contrast in comparison with conventional transmission electron microscopy. In addition, We show that for ptychography post-reconstruction focusing simplifies the workflow and reduces electron dose and beam damage.
具有无机纳米粒子的三维支架 DNA 折纸已被用于创建定制的多维纳米结构。然而，在高离焦时，传统的透射电子显微镜中 DNA 的图像对比度不如重的纳米粒子，因此无法使用未染色的样品的断层扫描同时解析 3D 支架中的生物和非生物成分。我们展示了使用电子相衬成像术从未染色的 DNA 折纸支架中的所有组件中恢复高对比度的相位信息。我们进一步定量评估了与传统的透射电子显微镜相比对比度的增强。此外，我们表明对于相衬成像术，后重建聚焦简化了工作流程并减少了电子剂量和束损伤。
