New Probes and Reagents for AFM Studies

描述：(申请者描述)原子力显微镜(AFM)是 功能强大、相对较新且发展迅速的分子成像技术 具有广泛的适用性。AFM首次提供了 单个生物分子在水溶液中处于其天然状态。重要 原子力显微镜可以对生物事件进行实时成像。这些因素包括时间延迟 淀粉样蛋白纤维的组装和沉积的图像，这是 阿尔茨海默病等致命疾病的发作。几乎所有类型II 糖尿病患者胰腺有细胞毒性淀粉样蛋白，形成 这被认为与疾病的发展直接相关。在……里面 原子力显微镜，样品被放置在原子平面上，如新解理的 云母和是由栅格扫描的尖端安装在一端的柔性 悬臂。生物样品的分辨率通常为50-100埃 并且受到尖端的锋利程度的限制。可用的最尖锐的提示 在商业上，对于轻敲模式，原子力显微镜的半径大约为4-50 nm。 最近，单壁碳纳米管被附着在AFM尖端上，并显示出 高宽比(尖端高度/底部)和清晰度的最佳组合 (约3 nm)到目前为止已有报道。这项研究的长期目标是 该计划旨在通过提供一系列新颖的、 分子尖端，旨在提高AFM图像的分辨率，即 人们可以观察到的细节水平，而不需要高度专业的 设备。这一建议建立在成功的模数合成的基础上 在该项目的头两年，TIP分子的原型。这个 合成尖端具有广泛的基础，旨在通过化学手段附着在商业广告上 尖端，这样只有一个分子可以放在尖端的最外面。 合成尖端逐渐变成设计用于探测的单个原子或官能团 样本。我们实验室制备的合成TIP分子的原型是 使用传统的AFM可以看到它们自己，展示了刚性和 分子的健壮性。其中一个目标是合成新的TIP分子 增加了底座的宽度和高度。这些图像将由传统的 AFM以确定在以下方面使用的最佳合成构建块 僵硬。另一个目标是开发将新提示附加到 常规的针尖和确定分辨率所提供的新合成 小费。尖端的设计使得探测样品的官能团可以 被改变了。例如，单个生物分子，例如抗体，可以是 附在一起，用来探测样品。AFM标签的概念将是 发展起来的。其意义在于提高了分辨率，应该是 可通过新的合成技巧获得。

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.