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)
Analytical Chemistry
Physical Chemistry of Solids and Surfaces, Material Characterisation
Final Report Abstract
The project was successful in the sense that a deeper understanding of the organization of small biomolecules on specific surfaces was gained. We could show how an initial preparation method is influencing the outcome of the coating (i.e. island film v. monolayer) which is not fully reversible. This may be of impact in future industrial applications where for instance small (bio-) molecules will replace more environmental harming processes (e.g. Cr for passivation). We could not fully fulfill our program with mono-crystalline surface for different reasons. It was difficult to find an appropriate student, then unexpected problems in restructuring surfaces occurred which had to be overcome by the construction of a new sample holder and the optimization and adaption of existing protocols. However, we succeeded and work in this direction is continued. The new sample holder that allows a much better control of surface temperatures will enable us to study in greater detail the co-adsorption of small bio-molecules with water. The fundamental process of organization of molecules under the influence of hydrogen bonds on crystalline surfaces is currently under investigations. The working RAS instrument will also contribute to these studies. Even if we may not able to observe glutathione we still can follow in situ the possible changes of the reconstructed metal surface under increasing humidity. The analytical methods we developed in the framework of the project were directly transferable to a new application oriented project related to the antithrombogenic coatings of stents. Because the new coatings are based on monolayers of small, biological relevant molecules and the questions arises what chemical functionality do they present under specific conditions our methodological results are directly useable.
