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

该奖项授予位于博尔德的科罗拉多大学，由生物基础设施部（生物科学理事会）的生物研究计划仪器开发，由材料科学部（数学和物理科学理事会）的生物材料计划共同资助。原子力显微镜（AFM）是一种用于成像，测量和操纵纳米级物质的工具，并通过使用称为悬臂梁的机械探针收集表面信息。AFM在生物学中的应用包括理解单个蛋白质的折叠和展开。蛋白质的功能需要正确的折叠，错误的折叠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，因为折叠和解折叠速率对力的亚微微牛顿（pN）变化敏感。该项目将具有成本效益的杠杆微加工与新型光学检测相结合，以实现1 pN时时间分辨率的1，600倍增加。拟议的发展将有利于生物学和材料科学领域。项目活动将为本科生和研究生提供优秀的跨学科培训。该项目的两个目标是开发用于生物测量的下一代AFM，该AFM将实现（i）世界领先的短期力精度与最先进的力稳定性相结合;（ii）将其成像能力扩展到形貌之外，以更高的分辨率绘制化学成分。第一个目标将在蛋白质折叠分析的背景下得到证明。为了提供10-100倍的力的稳定性的改善，一种新的差分检测系统的悬臂梁运动将被开发。该系统将使用微小的光斑尺寸（~2 μ m）来检测超小（L = 10 μ m）的杠杆，这些杠杆已经通过聚焦离子束进行了修改，以提高性能。这些杠杆能够实现世界领先的力精度以及长时间（100 s）的亚pN稳定性。第二个项目目标的重点是使用一种新的拉曼成像模式，提供3.5纳米的分辨率材料的化学特性。通过散射多个激光束的原子力显微镜针尖，建议原子力显微镜将协同合并这一令人兴奋的成像方式与世界领先的尖端样品的稳定性，并建立在一个强度的PI？实验室：将多个激光器集成到AFM中。最初的研究将集中在DNA包裹的碳纳米管上。研究结果将通过论文、演示和专利传播。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、纳米技术）。与AFM制造商（包括Asylum Research和Molecular Vista）的合作将促进更广泛的用户群的采用。

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.