IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Biomaterials Tuesday Sessions
       Session BI-TuP

Paper BI-TuP17
Determination of Adsorption Thermodynamics for Lysine Residues on Functionalized SAMs Using Surface Plasmon Resonance

Tuesday, October 30, 2001, 5:30 pm, Room 134/135

Session: Surface Characterization and Non-Fouling Surfaces Poster Session
Presenter: V.N. Vernekar, Clemson University
Authors: V.N. Vernekar, Clemson University
R.A. Latour, Clemson University
Correspondent: Click to Email
Although protein adsorption is key to many bioengineering problems, it is still not well understood. New comprehensive approaches to this problem are needed. In this study we take a systematic approach to address protein-surface adsorption by studying submolecular interactions of peptide residues with model surfaces. We hypothesize that combining the intermolecular thermodynamic contributions for peptide residue-surface adsorption with intramolecular residue-residue interactions will provide an approach to accurately predict overall protein adsorption. Accordingly, the objective of this study was to develop experimental techniques to measure residue-surface adsorption using surface plasmon resonance spectroscopy (SPR). The model residue-surface system selected for this initial study was poly-L-lysine (PL) and OH & COOH terminated Au-alkanethiol self assembled monolayers (SAMs). Preliminary studies were conducted to develop surface preparation and cleaning protocols necessary to obtain a stable SPR signal during the adsorption process. Adsorption studies were then conducted to measure the difference in signal as a function of surface functionality and PL concentration. Results show that the amount of adsorbed PL increases with increasing solution concentration, with the COOH-SAM adsorbing more PL than the OH-SAM for each concentration. These studies provide experimental data that is needed for calculating thermodynamic parameters for adsorption (Gibbs free energy, enthalpy, entropy) for each of these model systems. These values will be compared to results predicted from computational chemistry studies by others in our group for these same residue/surface systems.