AVS 49th International Symposium
    Biomaterials Tuesday Sessions
       Session BI+SS-TuM

Paper BI+SS-TuM3
Orientation in Oligo(ethylene glycol) Functionalised Self Assembled Monolayers Adsorbed on Gold Depending on the Oligomer Length

Tuesday, November 5, 2002, 9:00 am, Room C-201

Session: Platforms for Non-fouling and Patterned Surfaces
Presenter: M. Zwahlen, University of St Andrews, UK
Authors: M. Zwahlen, University of St Andrews, UK
S. Herrwerth, University of Heidelberg, Germany
W. Eck, University of Heidelberg, Germany
M. Grunze, University of Heidelberg, Germany
G. Haehner, University of St Andrews, UK
Correspondent: Click to Email
Oligo(ethylene glycol) (OEG) functionalised self-assembled monolayers (SAMs) have attracted considerable attention due to their protein repelling properties. The underlying mechanism is of high scientific relevance for future applications but has not yet been completely resolved. 'Steric repulsion', which describes the resistance to non-specific protein adsorption in the case of the polymer PEG does not explain the mechanism in densely packed SAM structures sufficiently. It has been suggested that one cru cial parameter for the interaction of OEG-modified surfaces with their environment is the orientation in the organic adlayer. This has motivated a number of structural investigations on OEG-SAMs. As a contribution to the ongoing discussion, we present a s tudy of the orientation in OEG-functionalised SAMs adsorbed on gold. It was measured as a function of the number of EG units in the molecule using soft X-ray absorption spectroscopy (NEXAFS). The results and their implications on the vacuum structure of the OEG-films will be discussed. The data will be compared to those obtained with complementary experimental techniques under similar as well as under different environmental conditions.