Protein interactions with oligo(ethylene glycol) (OEG) self-assembled monolayers: OEG stability, surface packing density and protein adsorption.

We present a study of protein adsorption on oligo(ethylene glycol) (OEG) self-assembled monolayers (SAMs) at a range of OEG surface densities. OEG SAMs were formed in mixed ethanol and water solutions at different assembly temperatures to adjust the packing density of EG4-SAMs. These SAMs were characterized using X-ray photoelectron spectroscopy (XPS). Fibrinogen adsorption on these surfaces was measured by a surface plasmon resonance (SPR) sensor at different temperatures. This work is aimed at addressing three important issues for protein-OEG interactions, i.e., (i) OEG stability, (ii) the correlation between OEG surface densities and surface non-fouling properties, and (iii) protein adsorption on OEG surfaces at different temperatures.