Fei Shen, North Carolina State University, Raleigh, NC, Jan Genzer, North Carolina State University, Raleigh, NC, Orlando J. Rojas, North Carolina State University, Raleigh, NC, Patrick Gurgel, ProMetic Life Sciences Inc., Mount-Royal, QC, Canada, and Ruben Carbonell, North Carolina State University, Raleigh, NC.
Two-component self-assembled monolayers (SAMs) of oligo(ethylene glycol)-terminated alkanethiols HS(CH2)11(CH2CH2O)3OH and amine functionalized oligo(ethylene glycol) alkanethiols HS(CH2)11(CH2CH2O)6NH2 could be an excellent candidate as an anchor layer for the immobilization of ligands or proteins in the study of protein-ligand and protein-protein binding events on surfaces with lower background from non-specific protein binding. Mixed SAMs are formed by the competitive adsorption of thiols, consequently, the composition of the SAM and surface properties depends on the concentration of thiol in solution and preparation conditions such as solvent, adsorption time and the presence of salt. In this work, the study of the surface properties of this two-component SAM on gold surface and its dependency on thiol binding conditions is reported, by using X-ray photoelectron spectroscopy (XPS), measurement of contact angles, and atomic force microscopy (AFM) with amine functionalized probe. The amount of proteins adsorbed on heterogeneous SAMs prepared under different conditions will be measured by Surface Plasmon Resonance (SPR).