3D Motion of DNA-Au Nanoconjugates in Graphene Liquid Cell Electron Microscopy
3D Motion of DNA-Au Nanoconjugates in Graphene Liquid Cell Electron Microscopy
复制标题
DOI：
10.1021/nl402694n
复制
发表时间：
2013-09-01
期刊：
影响因子：
10.8
通讯作者：
Alivisatos, A. Paul
中科院分区：
文献类型：
--
作者：
Chen, Qian;Smith, Jessica M.;Alivisatos, A. Paul
液相透射电子显微镜（TEM）可以在液体介质中探测和可视化具有纳米级结构或功能细节的动态事件。早期的努力集中在硬质材料系统的生长和转变动力学上，依赖于它们在电子束下的稳定性。我们最近开发的石墨烯液体电池技术将这种成像的空间分辨率推到了原子尺度，但仍然专注于金属纳米晶体的生长轨迹。在这里，我们采用这种技术来成像三维（3D）的软材料的动力学，而不是双链（dsDNA）连接Au纳米晶体作为一个例子，在纳米分辨率。我们首先证明，石墨烯液体细胞可以密封的水样品溶液的蒸气压比以前研究的高真空TEM。然后，从定量分析的真实的时间的运动轨迹，我们表明，dsDNA的状态和配置决定了连接的纳米晶体在整个成像时间分钟的运动。dsDNA的这种持续连接能力使得通过TEM对其动力学进行前所未有的连续成像成为可能。此外，惰性石墨烯表面最大限度地减少了样品基底的相互作用，并允许整个纳米结构在液体环境中自由旋转;因此，我们开发并实现了从旋转时捕获的一系列2D投影TEM图像中重建纳米结构的3D配置和运动。除了进一步证明纳米缀合物的结构稳定性之外，该重建还展示了TEM的3D动态成像，超出了其在观察扁平和干燥样品中的常规使用。总之，我们预见了石墨烯液池TEM在纳米分辨率下成像3D生物分子转化或相互作用动力学中的新的和令人兴奋的用途。
Liquid-phase transmission electron microscopy (TEM) can probe and visualize dynamic events with structural or functional details at the nanoscale in a liquid medium. Earlier efforts have focused on the growth and transformation kinetics of hard material systems, relying on their stability under electron beam. Our recently developed graphene liquid cell technique pushed the spatial resolution of such imaging to the atomic scale but still focused on growth trajectories of metallic nanocrystals. Here, we adopt this technique to imaging three-dimensional (3D) dynamics of soft materials instead, double strand (dsDNA) connecting Au nanocrystals as one example, at nanometer resolution. We demonstrate first that a graphene liquid cell can seal an aqueous sample solution of a lower vapor pressure than previously investigated well against the high vacuum in TEM. Then, from quantitative analysis of real time nanocrystal trajectories, we show that the status and configuration of dsDNA dictate the motions of linked nanocrystals throughout the imaging time of minutes. This sustained connecting ability of dsDNA enables this unprecedented continuous imaging of its dynamics via TEM. Furthermore, the inert graphene surface minimizes sample substrate interaction and allows the whole nanostructure to rotate freely in the liquid environment; we thus develop and implement the reconstruction of 3D configuration and motions of the nanostructure from the series of 2D projected TEM images captured while it rotates. In addition to further proving the nanoconjugate structural stability, this reconstruction demonstrates 3D dynamic imaging by TEM beyond its conventional use in seeing a flattened and dry sample. Altogether, we foresee the new and exciting use of graphene liquid cell TEM in imaging 3D biomolecular transformations or interaction dynamics at nanometer resolution.