In situ investigation of the interaction between water and small peptides on Au(110) and Cu(110) surfaces using near ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) and reflection anisotropy spectroscopy (RAS)

该项目的目标是深入了解水与金属表面生物分子相互作用的过程。特别是，我们想要澄清以下关于金属表面上的小生物分子的问题：它们是如何吸附到表面的？它们在表面是如何相互作用的？水在这些过程中扮演什么角色？共吸附金属离子的影响是什么？因此，我们计划通过研究表面结构和环境(压力、温度和pH)对这些过程的影响来研究水和小肽在金属表面的相互作用。这将包括研究水对氨基酸在金属表面的分解反应的影响。这些现象将用近环境压力x射线光电子能谱(NAP-XPS)来研究，这是一种新的技术，使我们能够在更现实的压力和温度条件下在分子水平上原位研究表面结构。这项研究将得到反射各向异性光谱(RAS)测量的补充，提供关于表面吸附分子的成键和取向的信息。其他实验方法将被用来进一步表征表面。其中包括LEED、STM、椭偏仪、红外光谱和拉曼光谱。我们将使用两种金属的单晶面：金和铜分别作为惰性表面和活性表面的模型。谷胱甘肽系统(g-Glu-Cys-Gly，GSH)及其组成的氨基酸，以及结构上相关的双肽g-谷氨酰半胱氨酸(g-Glu-Cys)和L-半胱氨酸甘氨酸(Cys-Gly)将是我们研究的重点。L-半胱氨酸将是我们的控制分子，因为这一物种与两种金属表面的相互作用已经得到了广泛的研究。

The goal of this project is to gain insight into the processes involved in interactions between water and biomolecules at metal surfaces. In particular, we want to elucidate the following questions regarding small biomolecules on metal surfaces: How do they adsorb to the surface? How do they interact at the surface? What is the role of water in these processes? And what is the influence of co-adsorbed metal ions? Therefore, we plan to study the interactions of water and small peptides on metal surfaces by investigating the effects of the surface structure and the environment (pressure, temperature, and pH) on these processes. This will include a study of the influence of water on the decomposition reactions of amino acids on metal surfaces. These phenomena will be studied with near-ambient pressure x-ray photoelectron spectroscopy (NAP-XPS), a new technique that allows us to study the surface structure at the molecular level in situ under more realistic pressure and temperature conditions. This study will be complemented by reflection anisotropy spectroscopy (RAS) measurements, providing information about bonding and orientation of adsorbed molecules on the surface. Other experimental methods will be used for further characterisation of the surfaces. These include LEED, STM, ellipsometry, and ir, and Raman spectroscopy. We will use single crystal surfaces of two metals: gold and copper as models for an inert and a reactive surface, respectively. The system of glutathione (g-Glu-Cys-Gly, GSH), its component amino acids, and the structurally related di-peptides g-glutamylcysteine (g-Glu-Cys) and L-cysteinylglycine (Cys-Gly) will be the main focus of our study. L-cysteine will be our control molecule, as the interaction of this species with both metal surfaces has been studied extensively.