Interfacial tension analysis of oligo(ethylene glycol)-terminated self-assembled monolayers and their resistance to bacterial attachment.


Journal Article

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.

Full Text

Cited Authors

  • Ista, LK; López, GP

Published Date

  • September 2012

Published In

Volume / Issue

  • 28 / 35

Start / End Page

  • 12844 - 12850

PubMed ID

  • 22891854

Pubmed Central ID

  • 22891854

Electronic International Standard Serial Number (EISSN)

  • 1520-5827

International Standard Serial Number (ISSN)

  • 0743-7463

Digital Object Identifier (DOI)

  • 10.1021/la302601x


  • eng