Department of Chemistry, Research Institute for Basic Sciences, Kyung Hee University, Seoul 02447, Republic of Korea.
Center for Research Equipment, Korea Basic Science Institute, Cheongju 28119, Republic of Korea.
Anal Chem. 2021 Feb 9;93(5):2871-2878. doi: 10.1021/acs.analchem.0c04264. Epub 2021 Jan 17.
Here, we report three-dimensional (3-D) visualization of dendrimer-encapsulated Pt nanoparticles (Pt DENs) by using 3-D electron tomography to reveal intricate structural characteristics of their whole organic-inorganic hybrid nanostructure. We reconstructed the 3-D spatial volume of Pt DENs by back-projecting a tilt series of two-dimensional (2-D) projections of Pt nanoparticles encapsulated inside dendrimers negatively stained with uranyl acetate. The direct 3-D visualization of Pt DENs elucidated their encapsulation characteristics with the spatial imaging of Pt nanoparticles embraced inside dendrimers in three dimensions. The encapsulation characteristics of Pt DENs were further verified with selective electrochemical poisoning experiments. In addition, quantitative 3-D structural characterization of Pt DENs provided more accurate and precise size distributions of nanoparticles than those obtained from conventional 2-D transmission electron microscopy analysis relying only on a 3-D structure projected on a 2-D plane.
在这里，我们通过使用三维电子断层扫描来报告树枝状聚合物包裹的 Pt 纳米粒子（Pt DENs）的三维可视化，以揭示其整个有机-无机杂化纳米结构的复杂结构特征。我们通过反向投影一系列用醋酸铀酰负染的树枝状聚合物内部包裹的 Pt 纳米粒子的二维（2-D）投影的倾斜系列来重建 Pt DENs 的三维空间体积。Pt DENs 的直接三维可视化阐明了它们的封装特征，即 Pt 纳米粒子在三维空间中被包裹在树枝状聚合物内。通过选择性电化学中毒实验进一步验证了 Pt DENs 的封装特征。此外，Pt DENs 的定量 3-D 结构特征提供了比仅依赖于投影在二维平面上的 3-D 结构的传统二维透射电子显微镜分析更准确和精确的纳米粒子尺寸分布。
