High-resolution low-voltage TEM for imaging the process of mineralization at the TMV/inorganic interface: Towards understanding the mechanical properties of bio/inorganic multilayer systems

用于对 TMV/无机界面矿化过程进行成像的高分辨率低压 TEM：了解生物/无机多层系统的机械性能

• 批准号: 286663312
• 负责人: Professor Dr. Joachim Bill
• 金额: --
• 依托单位: Abteilung Chemische Materialsynthese
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/286663312?language=en
• 关键词: resolution; low; voltage; TEM; imaging

Biomineralization is the natural process of construction and induration of tissues, which outmatch several synthesized products in their physical and chemical properties. Appreciably, one tries to synthesize comparable technical relevant hybrid materials by bio-inspired mineralization. In the existing project we would like to contribute to a better understanding of the mechanism of protein based mineralization of zinc sulfide (ZnS) and zinc oxide (ZnO) on the biotemplate tobacco mosaic virus (TMV) by imaging the organic/inorganic glue line with high-resolution. The obtained insights will help to control the structure of this boundary surface, which are essential for synthesis of nano-sized functional material with tailored properties.Toward the commonly used techniques to image organic materials by negative staining of the specimen, which leads to resolutions in the range of several nanometer or embedding them in vitrified ice with a resolution up to 0.4 nm at acceleration voltages of 300 kV, we count on our newly developed low-voltage transmission electron microscope (TEM) available in spring 2016 to image the surface boundary. High resolution images of the glue line at acceleration voltages of 20-80 kV is possible due to not only spherical but also chromatic aberration correction of the objective lens. In the frame of this project elaborate sample preparation methods like graphene-sandwiching and/or deuterating the specimen will be investigated to image the organic/inorganic boundary surface. Additionally, a further goal of this project is to reveal in situ if the bio-inspired mineralization begins with heterogeneous or homogenous nucleation.In preliminary work of the Stuttgart group, mineralization procedures for selective deposition of ZnS and ZnO on tobacco mosaic virus (TMV) were accomplished. In the frame of this project multilayered nacre-like structures (MLS) on the base of TMV/ZnS and TMV/ZnO, respectively will be produced and investigated. The mechanical properties investigations of ZnO-based MLS with wildtype (wt) TMV (wt-TMV/ZnO) and the TMV mutant TMV_Cys (TMV_Cys/ZnO) and therefore with additional thiols in the boundary surface revealed that the MLS containing the mutant showed an increase in hardness compared to wt-based one. Those MLS will also be imaged with our low-voltage TEM to analyze ultrastructural disparity of the protein-mineral-boundary surface and to correlate that with mechanical properties. To gain an insight with the TEM into the mineralization at the surface as well as in the inner channel of the virus it is additionally planned to assemble small virus-like particles (VLP) and mineralized them in vertical oriented arrays.

生物矿化是组织的建设和硬化的自然过程，它在其物理和化学特性中均超过了几种合成产品。显然，人们试图通过生物启发的矿化合成可比的技术相关杂种材料。在现有项目中，我们想通过对生物板烟草烟丝病毒（TMV）上的蛋白质硫化物（ZnS）和氧化锌（ZnO）的矿化机理有所帮助，通过对具有高分辨率的有机/无机胶水线进行成像。 The obtained insights will help to control the structure of this boundary surface, which are essential for synthesis of nano-sized functional material with tailored properties.Toward the commonly used techniques to image organic materials by negative staining of the specimen, which leads to resolutions in the range of several nanometer or embedding them in vitrified ice with a resolution up to 0.4 nm at acceleration voltages of 300 kV, we count on our newly开发的低压透射电子显微镜（TEM）在2016年春季可用，以对表面边界进行图像。胶线在加速度电压下的高分辨率图像不仅是球形晶状体的球形矫正校正，而且还可能是20-80 kV的。在该项目的框架内，将研究样品制备方法，例如石墨烯 - 桑德威奇和/或剥离样品，以对有机/无机边界表面进行成像。此外，该项目的进一步目标是在原位揭示生物启发的矿化始于异构或同质成核。在该项目的框架内，将分别生产和研究TMV/ZNS和TMV/ZnO的多层Nacre样结构（MLS）。使用WildType（WT）TMV（WT-TMV/ZnO）和TMV突变体TMV_CYS（TMV_CYS/ZnO）的基于ZnO的MLS（WT）TMV（WT）TMV（WT）MLS（TMV_CYS/ZnO）的机械性能研究，因此，边界表面的其他硫醇显示出包含该突变体性硬度的ML与WT基于WT相比提高。这些MLS还将与我们的低压TEM成像，以分析蛋白质矿物质边界表面的超微结构差异，并将其与机械性能相关。为了使TEM进入表面的矿化以及病毒的内通道中的洞察力，还计划组装小病毒样颗粒（VLP），并将它们矿化在垂直方向的阵列中。