Interfacial tension analysis of oligo(ethylene glycol)-terminated self-assembled monolayers and their resistance to bacterial attachment.
The fouling resistance of oligo(ethylene glycol) (OEG)-terminated self-assembled monolayers (SAMs) of alkanethiolates on gold has been well established. Although hydration of the OEG chains seems key to OEG-SAM resistance to macromolecular adsorption and cellular attachment, the details of how hydration prevents biofouling have been inferred largely through computational methods. Because OEG-SAMs of different lengths exhibit differing degrees of fouling resistance, the interactions between water and OEG-SAMs leading to fouling resistance can be deduced by comparing the properties of fouling and nonfouling OEG-SAMs. While all OEG-SAMs had similar water contact angles, contact angles taken with glycerol were able to individuate between different OEG-SAMs and between fouling and nonfouling OEG-SAMs. Subsequent estimation of surface and interfacial tension using a colloidal model showed that nonfouling surfaces are associated with an increased negative interfacial tension between those OEG-SAMs that resisted attachment and water. Further analysis of this interfacial tension experimentally confirmed current mathematical models that cite OEG-water hydrogen-bond formation as a driving force behind short-term fouling resistance. Finally, we found a correlation between solid-water interfacial tension and packing density and molecular density of ethylene glycol.
Center for Biomedical Engineering and Department of Chemical and Nuclear Engineering, The University of New Mexico, Albuquerque, New Mexico 87106, United States. lkista@unm.edu
Linnea K
LK
Ista
Gabriel P
GP
López
D000473:Alkanes / Q000737:chemistry; D001422:Bacterial Adhesion / Q000187:drug effects; D057219:Biofouling / Q000517:prevention & control; D003102:Colloids; D006046:Gold / Q000737:chemistry; D044129:Halomonadaceae / Q000187:drug effects / Q000502:physiology; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000494:pharmacology; D013500:Surface Tension; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
D000473:Alkanes; D003102:Colloids; D014867:Water; D011092:Polyethylene Glycols; D006046:Gold