AVS 49th International Symposium
    Biomaterials Wednesday Sessions
       Session BI+AS-WeM

Paper BI+AS-WeM8
Force Spectroscopy of Self-Assembled Monolayers Containing 'Sandwiched' Oligo(Ethylene Glycol) Interfaces on Gold under Electrolyte Solution

Wednesday, November 6, 2002, 10:40 am, Room C-201

Session: Ambient Surface Science Techniques
Presenter: G. Haehner, University of St Andrews, UK
Authors: G. Haehner, University of St Andrews, UK
C. Dicke, University of St Andrews, UK
S. Herrwerth, University of Heidelberg, Germany
W. Eck, University of Heidelberg, Germany
M. Grunze, University of Heidelberg, Germany
Correspondent: Click to Email
Non-specific interactions between biomolecules and (synthetic) organic surfaces, and in particular materials which are resistant to the adsorption of proteins from biological media, are of crucial importance to the fields of biomaterials, biosensors and medical devices. Chemically functionalized (charged and hydrophobic) scanning force microscope probes can mimic local structures of proteins and hence allow it to study the influence of these parameters on the overall observed interaction separately. Oligo(ethylene glycol) (OEG) terminated self-assembled monolayers on gold show high inertness towards the non-specific adsorption of proteins. The underlying mechanism, however, has not yet been resolved completely. It appears that water as well as hydronium and/or hydroxyl ions play a central role. In order to scrutinize the interaction, the accessibility of the OEG interface to molecules/ions from solution was varied. This was accomplished by the molecular structure: the functional (OEG) part was terminated with hydrophobic chains of different length resulting in 'sandwich'-film- structures. Force spectroscopy measurements on these layered structures with hydrophobic probes under electrolyte solution reveal the importance of the different contributing factors to the overall interaction.