Evidence for why tri(ethylene oxide) functionalized Si-C linked monolayers on Si(111) have inferior protein antifouling properties relative to the equivalent alkanethiol monolayers assembled on gold

High quality methoxy-terminated monolayers containing a tri(ethylene oxide) moiety were formed on Si(111)-H surfaces in thermal hydrosilylation reactions. X-ray photoelectron spectroscopy, contact angle, and X-ray reflectivity measurements suggested that the suboptimal protein anti-fouling properties of these Si-C linked monolayers were due to a reduced lateral packing density of the chains resulting in a disordered layer with insufficient internal and external hydrophilicity.