Surface spectroscopy and microscopy studies of molecular films at electrified interfaces

本计画的主要目的是研究沉积在金属电极上的功能性磷脂单分子层与双分子层的结构与反应性。这些膜的功能性将由肽和蛋白质的存在来确定。我们的目标是了解电场如何影响由磷脂和胆固醇组成的混合双层的稳定性，将蛋白质纳入双层和电子和离子转移通过蛋白质纳入支持的双层。为了实现这些目标，我们将采用电化学方法，扫描探针显微镜，如扫描隧道显微镜（STM）和原子力显微镜（AFM），原位光子偏振调制傅里叶变换红外反射吸收光谱（PM-IRRAS），表面增强红外和拉曼光谱和中子散射技术。我们将使用电化学技术来控制膜的物理状态，并使用扫描探针显微镜来成像膜的场驱动转换。此外，光谱和中子散射技术将被用来研究有机分子的构象变化和它们在膜内的排序。我们的目标是获得几个生物相关的过程，如：（i）抗菌肽（AMP）和淀粉样肽与磷脂双层的相互作用，（ii）在溶液中的核脂质与互补核碱基的单层和双层的相互作用，（iii）蓝色铜氧化酶的构象和取向的变化发生在氧化/还原过程中的氧化还原中心。金属电极表面被仿生膜覆盖，可以带电，并且可以向膜施加10^7 - 10^8V/m量级的电场。这些场具有与作用于生物膜的场相当的大小。我们的目标是利用这一独特的机会，操纵生物分子的领域和监测构象和取向的变化所引起的领域使用的表面分析技术。此外，对于在金属电极处支撑的膜，电化学方法可用于将关于膜中的主客体相互作用的分析信息转换为用于分析检测的电信号。**

The general objective of this project is to study the structure and reactivity of functional monolayers and bilayers of phospholipids deposited onto a metal electrode at the metal-solution interface. The functionality of these films will be determined by the presence of peptides and proteins. Our goal is to learn how the electric field affects the stability of mixed bilayers composed of phospholipids and cholesterol, incorporation of proteins into the bilayer and electron and ion transfer through proteins incorporated into the supported bilayer. To achieve these goals, we will employ electrochemical methods, scanning probe microscopies such as scanning tunneling microscopy (STM) and atomic force microscopy (AFM), in situ photon polarization modulation Fourier transform infrared reflection absorption spectroscopy (PM-IRRAS), surface enhanced infrared and Raman spectroscopies and the neutron scattering technique. We will use electrochemical techniques to control the physical state of the film and the scanning probe microscopies to image the field driven transformations of the membranes. In addition, spectroscopic and neutron scattering techniques will be employed to study conformational changes of organic molecules and their ordering within the membrane. Our goal is to obtain fundamental understanding of several biorelevant processes such as:(i) interactions of antimicrobial (AMPs) and amyloid peptides with phospholipid bilayers, (ii) interactions of monolayers and bilayers of nucleolipids with complementary nucleobases in solution, (iii) conformational and orientational changes of blue copper oxidase enzymes occurring during oxidation/reduction of their redox center. The metal electrode surface, covered by a biomimetic membrane, can be charged and electric fields on the order of 10^7 - 10^8V/m can be applied to the membrane. These fields have comparable magnitude to the fields acting on biological membranes. Our goal is to use this unique opportunity to manipulate biomolecules with the field and to monitor conformational and orientational changes induced by the filed using the surface analytical techniques. In addition, for the membrane supported at a metal electrode, the electrochemical methods could be used for transduction of analytical information about the host guest interactions in the membrane to an electrical signal for analytical detection. **