Atomic force microscope for high-speed, nanomechanical and electrochemical characterizations

我们在物理、纳米科学和细胞生物学领域的各种研究活动需要纳米级分辨率原子力显微镜(AFM)，能够在生理相关条件下高速和先进的纳米机械表征粘附性生物样品，以及纳米级电化学。2.以DNA纳米技术和纳米光子学为研究重点的物理研究所(主要申请者)将主要利用原子力显微镜对基于DNA折纸的纳米/微结构及其动力学功能进行形态表征。2.物理研究所将进一步应用基于AFM的扫描电化学显微镜(SECM)，其中可以在AFM针尖下以纳米分辨率触发和监测电化学反应，以实现具有不同功能的可重构纳米光子(聚合物)亚表面，例如全息照相。它还将被4.物理研究所用来表征导电聚合物的膨胀和收缩行为。生物材料和生物分子系统研究所(IBBS)将利用原子力显微镜来研究生物膜运输过程的功能和调节。IBBS进一步寻求评估定制的2D和3D水凝胶中的静态和动态变化的材料特性，以控制生物细胞响应。细胞生物学和免疫学研究所将使用原子力显微镜测量细胞和组织力学，并调查上皮细胞行为是如何调节其微环境的。我们的典型样品，如复杂的DNA-折纸组件、异物表面、水凝胶、细胞和细胞仿制品，以及它们的构成单元，如DNA-折纸、生物分子、TOM(外膜转位酶)复合体、蛋白质、聚合物和金属纳米结构，必须在可控(生理相关)的条件下以纳米空间分辨率成像。与电子显微镜和光学显微镜相比，原子力显微镜提供了这样的功能，它是纳米科学和细胞生物学中最先进和成熟的技术。此外，所要求的AFM应提供多种操作模式，以实现高分辨率成像、高速成像(至少每秒7帧)、基于AFM针尖的SECM(至少低于100 nm空间分辨率)和用于纳米机械表征的力谱。它应该工作在尖端扫描配置中，并与倒置共焦显微镜兼容。斯图加特大学目前还没有提供这些多功能功能的AFM。因此，我们在很大程度上依赖于这种多功能工具的获得，以获得对(混合)基于DNA的纳米结构和基于导电聚合物的亚表面的组装和功能动力学、跨生物膜的传输过程、水凝胶控制的生物细胞反应以及上皮细胞和组织生理学的新见解。

Our various research activities in the fields of physics, nanoscience and cell biology require nanoscale resolution atomic force microscopy (AFM) capable of high-speed and advanced nanomechanical characterization of adhesive biological samples under physiologically relevant conditions as well as nanoscale electrochemistry. The 2. Physics Institute (leading applicant) with research focus on DNA-nanotechnology and nanophotonics, will predominantly employ the AFM to morphologically characterize DNA-origami-based nano-/microarchitectures as well as their dynamical functionalities. The 2. Physics Institute will further apply AFM-based scanning electrochemical microscopy (SECM), where electrochemical reactions can be triggered and monitored beneath the AFM tip with nanometer resolution, to realize reconfigurable nanophotonic (polymer) metasurfaces offering different functionalities, e.g. holography. It will also be used by the 4. Physics Institute to characterize the swelling and shrinking behaviour of conducting polymers. The Institute of Biomaterials and Biomolecular Systems (IBBS) will utilize the AFM to investigate the function and regulation of transport processes across biological membranes. IBBS further seeks to assess the static and dynamically changing material properties in tailored 2D and 3D hydrogels to control biological cellular responses. The Institute of Cell Biology and Immunology will use the AFM to measure cell and tissue mechanics and investigate how epithelial cell behaviour is modulated its microenvironment. Our typical samples, e.g. complex DNA-origami assemblies, metasurfaces, hydrogels, cells and cellular mimics as well as their constituting building block, e.g. DNA-origamis, biomolecules, TOM (translocase of the outer membrane) complexes, proteins, polymer and metal nanostructures, have to be imaged with nanometer spatial resolution under controllable (physiologically relevant) conditions. In contrast to electron and optical microscopy, atomic force microscopy, which is state of the art and a well-established technology in nanoscience and cell biology, offers such functionalities. Additionally, the requested AFM should provide a variety of operation modes enabling high-resolution imaging, high-speed imaging (at least 7 frames per second), AFM-tip-based SECM (at least sub-100 nm spatial resolution) and force spectroscopy for nanomechanical characterization. It should operate in tip-scanning configuration and be compatible with inverted confocal microscopes. An AFM providing these versatile functionalities is currently not available at the University of Stuttgart. We therefore heavily rely on the acquisition of such a versatile tool to gain new insight into the assembly and functional dynamics of (hybrid) DNA-based nanoarchitectures and conducting-polymer-based metasurfaces, the transport processes across biological membranes, the hydrogel-controlled biological cellular responses as well as epithelial cells and tissue physiology.