New Probes and Reagents for AFM Studies

描述：（申请人的描述）原子力显微镜（AFM）是一种 强大的、相对较新且快速发展的分子成像技术 具有广泛的适用性。 AFM 首次提供 水溶液中处于天然状态的单个生物分子。重要 实时生物事件可以通过 AFM 成像。其中包括延时摄影 淀粉样原纤维的组装和沉积的图像，这是淀粉样蛋白原纤维的核心过程 阿尔茨海默病等致命疾病的发作。几乎都是II型 糖尿病患者具有细胞毒性的胰腺淀粉样蛋白，形成 这被认为与疾病的发展直接相关。在 AFM，将样品放置在原子级平坦的表面上，例如新切割的表面 云母并由安装在柔性末端的锋利尖端进行光栅扫描 悬臂。生物样本的分辨率通常为 50-100 埃 并且受到尖端锋利度的限制。最锋利的提示 商业上用于轻敲模式 AFM 的半径约为 4-50 nm。 最近，将单壁碳纳米管附着在 AFM 尖端上，并显示 纵横比（尖端高度/底部）和清晰度的最佳组合 （约 3 nm）迄今为止报道的。本研究的长期目标 计划旨在通过提供一系列新颖、 分子锐尖旨在提高 AFM 图像的分辨率，即 无需高度专业化即可观察到的细节程度 设备。该提案建立在成功的模块化综合的基础上 在该项目的前两年，原型尖端分子。的 合成吸头具有广泛的基础，旨在以化学方式附着在商业上 尖端，以便只有单个分子可以安装在尖端的最外层部分。 合成尖端逐渐变细为单个原子或官能团，旨在探测 样品。我们实验室制备的原型合成尖端分子是 使用传统的 AFM 可以看到它们本身，展示了刚性和 分子的稳健性。一个目标是合成新的尖端分子 增加底座的宽度和高度。这些将通过传统方式成像 AFM 用于确定最佳的合成构建模块 刚性。另一个目标是开发将新技巧附加到 传统的尖端并确定新合成提供的分辨率 提示。尖端的设计使得探测样品的功能组可以 被改变。例如，单个生物分子，例如抗体，可能是 连接并用于探测样品。 AFM 标签的概念是 开发的。其意义在于提高分辨率， 可通过新的合成尖端获得。

DESCRIPTION: (Applicant's Descritpion) Atomic force microscopy (AFM) is a powerful, relatively recent and rapidly expanding molecular imaging technique of broad applicability. AFM is providing for the first time images of individual biomolecules in their native state in aqueous solution. Important biological events in real time may be imaged by AFM. These include time lapse images of the assembly and deposition of amyloid fibrils, a process central to the onset of fatal diseases such as Alzheimer's disease. Nearly all type II diabetes mellitus patients have cytotoxic pancreatic amyloid, the formation of which is thought to be directly related to the development of the disease. In AFM, the sample is placed on an atomically flat surface such as freshly cleaved mica and is raster scanned by a sharp tip mounted at the end of a flexible cantilever. Resolution for biological specimens is typically 50-100 Angstroms and is limited by the sharpness of the tip. The sharpest tips available commercially for tapping mode AFM have a radius of approximately 4-50 nm. Recently, single walled carbon nanotubes were attached to AFM tips and show the best combination of' aspect ratio (tip height/base) and sharpness (approximately 3 nm) reported to date. The long term objective of this research program is to enhance the capabilities of AFM by providing a series of novel, molecularly sharp tips designed to improve the resolution of AFM images, i.e. the level of detail one can observe, without the need for highly specialized equipment. This proposal builds on the successful modular synthesis of prototype tip molecules during the first two years of the project. The synthetic tips have a broad base designed to attach chemically to a commercial tip so that only a single molecule can fit on the outermost part of the tip. The synthetic tips taper to a single atom or functional group designed to probe the sample. Prototype synthetic tip molecules prepared in our laboratory are themselves visible using conventional AFM, demonstrating the rigidity and robustness of the molecules. One aim is to synthesize new tip molecules with increased breadth of the base and height. These will be imaged by conventional AFM to determine the best synthetic building blocks to use in terms of rigidity. Another aim is to develop methodology for attaching the new tips to a conventional tip and to determine the resolution provided by the new synthetic tips. The tips are designed so that the functional group probing the sample can be changed. For example, a single biomolecule, e.g. an antibody, may be attached and used to probe the sample. The concept of an AFM label will be developed. The significance lies in the enhanced resolution that should be obtainable with the new synthetic tips.