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SYSO: Symposium Self-organizing Surfaces and Interfaces
SYSO 3: Self-Organizing Surfaces and Interfaces - Posters
SYSO 3.16: Poster
Mittwoch, 25. März 2009, 17:30–19:30, P3
Growth kinetics of oligo-ethylene glycol thiols on Au-surfaces - Real-time IR studies under aqueous conditions — •Stefan Zorn1, Nathan Martin2, Alexander Gerlach1, and Frank Schreiber1 — 1Institut für Angewandte Physik, Universität Tübingen, Tübingen, Germany — 2Montana State University, Bozeman, MT, USA
Oligo-ethylene glycols (OEGs) are an important model system for biotechnological applications. In particular OEG SAMs are able to form protein resistant surfaces. The underlying mechanism of this property is not fully understood until now. However, recent investigations indicate that solvent interaction with the OEG layer plays an important role in the capacity to withstand protein absorption [1].
While n-alkane SAM growth has been intensively studied [2], only little is known about OEG SAM growth kinetics, although the structure of the OEGs including their confirmation and defects is crucial for their performance in protein resistance. Using a polarisation modulation infrared reflection absorption spectroscopy (PMIRRAS) setup with a home made liquid cell we were able to monitor the different stages of growth and identify the different conformations of the OEG SAM dependent on the surface coverage. By comparing the absorption bands in the region of the strong C-O-C stretching mode we were also able to describe the underlying growth kinetics and to model the changing ratio of all-trans and helical conformation during growth.
[1] M.W.A. Skoda et al., Langmuir 23 (2007) 970.
[2] F. Schreiber, Prog. Surf. Sci. 65 (2000) 151.