Meana-Pañeda Rubén, Ji Canran, Van Cong T S, Reboul Cyril F, Kang Sungsu, Kim Sungin, Rhee Jinho, Lee Yunseo, Ercius Peter, Czaja Wojciech, Park Jungwon, Elmlund Hans
Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
Department of Mathematics, University of Maryland, College Park, MD 20742-4015, USA.
Sci Adv. 2025 Aug 8;11(32):eady1413. doi: 10.1126/sciadv.ady1413. Epub 2025 Aug 6.
Atomic-resolution structure identification of nanocrystals by graphene liquid cell electron microscopy (GLC-EM) has revealed that small, solubilized platinum nanocrystals consist of an ordered crystalline core surrounded by mobile surface atoms, which dissociate during oxidative etching, resulting in distinct temporal structural states. Requirements imposed by the 3D reconstruction algorithm limit the number of structural states that can be resolved. We introduce a regularized 3D reconstruction algorithm that exploits the redundancy inherent in the experimental data, allowing us to improve the time resolution. Our developments provide a comprehensive molecular picture at unprecedented spatial and temporal resolution of the nonlinear, linear, and fluctuating dynamic phenomena that single nanocrystals undergo during the GLC-EM experiment. We determined atomic structures of 66 temporal structural states, extracted from 15 time trajectories of individual nanocrystals. Large (478 to 698 atoms) and small (<300 atoms) nanocrystals show etching that preserves a stable core, whereas mid-sized (351 to 571 atoms) nanocrystals present dynamics that change the coordination of the core.
通过石墨烯液体池电子显微镜（GLC-EM）对纳米晶体进行原子分辨率结构鉴定发现，小的、可溶解的铂纳米晶体由一个有序的晶体核心组成，其周围是可移动的表面原子，这些原子在氧化蚀刻过程中会解离，从而产生不同的瞬时结构状态。三维重建算法的要求限制了可分辨的结构状态数量。我们引入了一种正则化三维重建算法，该算法利用了实验数据中固有的冗余性，使我们能够提高时间分辨率。我们的进展以前所未有的空间和时间分辨率提供了单个纳米晶体在GLC-EM实验过程中经历的非线性、线性和波动动态现象的全面分子图景。我们确定了从单个纳米晶体的15条时间轨迹中提取的66个瞬时结构状态的原子结构。大的（478至698个原子）和小的（<300个原子）纳米晶体显示出蚀刻后保留稳定核心的情况，而中等大小的（351至571个原子）纳米晶体呈现出改变核心配位的动态变化。
