Scanning Conductance Probe Microscope for Chemical Mapping

用于化学绘图的扫描电导探针显微镜

• 批准号: 9513233
• 负责人: Stuart Lindsay
• 金额: $ 44.3万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-03-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9513233&HistoricalAwards=false
• 关键词: Scanning; Conductance; Probe; Microscope; Chemical

We propose to build an atomic force microscope with a conducting tip to identify sites where electroactive molecules span an otherwise insulating lipid membrane. The microscope will be capable of detecting currents of a few femtoamps, and will operate under environmental and temperature (80-300K) control. Recent work by Mazur and Hipps indicates that the current-voltage characteristics at conductive sites are related to the redox chemistry of the electroactive molecules and we propose to study this phenomenon using well-characterized molecular assemblies of porphyrin-linked alkanethiols with the goal of distinguishing individual organic molecules. Operation at low temperatures will be used to control ion currents (such as unwanted surface conduction in a water layer) and to stiffen soft samples (leading to higher AFM resolution). Our ultimate goal is to develop a new spatial-mapping tool for studying electronic and ionic processes across cell membranes. The first biological sample we will study will be the well characterized (and highly ordered) arrays of the photosynthetic reaction center from Rhodopseudomonas viridis. We hope to be able to identify the cytochrome bcl complexes and determine their spatial distribution in the membrane.

我们建议建立一个带有导电尖端的原子力显微镜，以识别电活性分子跨越其他绝缘类脂膜的位置。该显微镜将能够检测几个飞安的电流，并将在环境和温度(80-300K)控制下工作。Mazur和Hipps最近的工作表明，导电部位的电流-电压特性与电活性分子的氧化还原化学有关，我们建议使用表征良好的卟啉连接的烷硫醇分子组装来研究这一现象，目的是区分单个有机分子。低温操作将用于控制离子电流(如水层中不需要的表面传导)，并使软样品变硬(导致更高的AFM分辨率)。我们的最终目标是开发一种新的空间映射工具，用于研究跨细胞膜的电子和离子过程。我们将研究的第一个生物样本将是绿色红假单胞菌光合作用反应中心的特征良好(和高度有序)的阵列。我们希望能够鉴定细胞色素BCL复合体，并确定它们在膜上的空间分布。