IDBR: Type A, An Ultraprecise and Ultrastable Atomic Force Microscope for Multimodal Characterization of Biological Molecules and Materials

该奖项由科罗拉多大学博尔德分校生物基础设施部(生物科学局)的生物研究仪器开发计划颁发，由材料科学部(数学和物理科学局)的生物材料计划联合资助。原子力显微镜(AFM)是一种用于在纳米级对物质进行成像、测量和操作的工具，它通过使用一种名为悬臂的机械探头来收集表面信息。原子力显微镜在生物学中的应用包括了解单个蛋白质的折叠和展开。蛋白质的功能需要适当的折叠，错误的折叠可能会导致阿尔茨海默氏症等疾病。在折叠研究中，力的稳定性是至关重要的，因为折叠和展开速率对亚皮牛顿(Pn)力的变化很敏感。该项目将经济高效的悬臂梁微加工与新型光学检测相结合，在1PN下实现时间分辨率提高1600倍。拟议的发展将使生物学和材料科学领域受益。项目活动将为本科生和研究生提供优秀的跨学科培训。该项目的双重目标是开发新一代AFM用于生物测量，实现(I)世界领先的短时力精度和最先进的力稳定性，以及(Ii)将其成像能力扩展到地形之外，以增强分辨率绘制化学成分图。第一个目标将在蛋白质折叠分析的背景下进行演示。为了将力的稳定性提高10-100倍，将开发一种新型的悬臂运动差分检测系统。该系统将使用一个微小的光斑尺寸(~2？m)来检测超小(L=10？m)悬臂梁，这些悬臂梁已经被聚焦离子束修改以提高性能。这些悬臂使世界领先的力精度与低于PN的长期稳定性相结合(100 S)。第二个项目目标是使用一种提供3.5纳米分辨率的新型拉曼成像设备对材料进行化学表征。通过从原子力显微镜针尖上散射多束激光，建议的原子力显微镜将把这一令人兴奋的成像方式与世界领先的针尖-样品稳定性结合在一起，并建立在皮耶？S实验室的优势之上：将多个激光集成到一个原子力显微镜中。最初的研究将集中在DNA包裹的碳纳米管上。结果将通过论文、演示文稿和专利进行传播。将从该项目中受益的生物研究社区包括单分子生物物理学、膜蛋白质生物学、细胞结构、蛋白质折叠以及其他学科(例如物理学、材料科学和纳米技术)。与AFM制造商(包括庇护研究和分子视像)的合作将促进更广泛的用户基础的采用。

This award to the University of Colorado at Boulder, by the Instrument Development for Biological Research program, in the Division of Biological Infrastructure (Biological Sciences Directorate),is jointly funded by the Biomaterials Program in the Division of Materials Science (Math and Physical Sciences Directorate). Atomic force microscopy (AFM) is a tool used for imaging, measuring, and manipulating matter at the nanoscale, and gathers surface information by using a mechanical probe called a cantilever. Applications of AFM in biology include understanding the folding and unfolding of individual proteins. Protein function requires proper folding, and misfolding can lead to diseases such as Alzheimer's. In folding studies, force stability is critical since the folding and unfolding rates are sensitive to sub-piconewton (pN) changes in force. This project merges cost-effective micromachining of cantilevers with a novel optical detection to achieve a 1,600-fold increase in temporal resolution at 1 pN. The proposed developments will benefit the fields of biology, as well as materials science. Project activities will provide excellent interdisciplinary training for undergraduates as well as graduate students.The twin goals of this project are to develop a next generation AFM for biological measurements that achieves (i) world-leading short-term force precision coupled with state-of-the-art force stability and (ii) extend its imaging capability beyond topography to map chemical composition with enhanced resolution. The first goal will be demonstrated in the context of protein folding assays. To provide a 10-100-fold improvement in force stability, a novel differential detection system of cantilever motion will be developed. This system will use a tiny spot size (~2 ìm) to enable detection of ultra-small (L = 10 ìm) cantilevers, which have been modified by a focused ion beam for improved performance. These cantilevers enable world-leading force precision coupled with sub-pN stability over long periods (100 s). The second project goal focuses on chemical characterization of materials using a new Raman imaging modality that offers 3.5-nm resolution. By scattering multiple laser beams off the AFM tip, the proposed AFM will synergistically merge this exciting imaging modality with the world-leading tip-sample stability and builds upon a strength of the PI?s lab: integrating multiple lasers into an AFM. Initial studies will focus on DNA wrapped carbon nanotubes. Results will be disseminated via papers, presentations, and patents. Biological research communities that will benefit from this project include single-molecule biophysics, membrane protein biology, cellular structure, protein folding, as well as other disciplines (e.g., physics, material science, & nanotechnology). Collaborations with AFM manufacturers (including Asylum Research and Molecular Vista) will facilitate adoption by a wider user base.