White Rose University Consortium logo
University of Leeds logo University of Sheffield logo York University logo

Adhesive and conformational behaviour of mycolic acid monolayers

Zhang, Z., Pen, Y., Edyvean, R.G., Banwart, S.A., Dalgliesh, R.M. and Geoghegan, M. (2010) Adhesive and conformational behaviour of mycolic acid monolayers. Biochimica et Biophysica Acta - Biomembranes, 1798 (9). pp. 1829-1839. ISSN 0005-2736

Full text available as:
[img] Text
Geoghegan_11204.pdf

Download (2230Kb)

Abstract

We have studied the pH-dependent interaction between mycolic acid (MA) monolayers and hydrophobic and hydrophilic surfaces using molecular (colloidal probe) force spectroscopy. In both cases, hydrophobic and hydrophilic monolayers (prepared by Langmuir-Blodgett and Langmuir-Schaefer deposition on silicon or hydrophobized silicon substrates, respectively) were studied. The force spectroscopy data, fitted with classical DLVO (Derjaguin, Landau, Verwey, and Overbeek) theory to examine the contribution of electrostatic and van der Waals forces, revealed that electrostatic forces are the dominant contribution to the repulsive force between the approaching colloidal probe and MA monolayers. The good agreement between data and the DLVO model suggest that beyond a few nm away from the surface, hydrophobic, hydration, and specific chemical bonding are unlikely to contribute to any significant extent to the interaction energy between the probe and the surface. The pH-dependent conformation of MA molecules in the monolayer at the solid-liquid interface was studied by ellipsometry, neutron reflectometry, and with a quartz crystal microbalance. Monolayers prepared by the Langmuir-Blodgett method demonstrated a distinct pH-responsive behaviour, while monolayers prepared by the Langmuir-Schaefer method were less sensitive to pH variation. It was found that the attachment of water molecules plays a vital role in determining the conformation of the MA monolayers. (C) 2010 Elsevier B.V. All rights reserved.

Item Type: Article
Copyright, Publisher and Additional Information: © 2010 Elsevier. This is an author produced version of a paper subsequently published in Biochimica et Biophysica Acta - Biomembranes. Uploaded in accordance with the publisher's self-archiving policy.
Keywords: Mycolic acid; Monolayer; Neutron reflectometry; Force spectroscopy; DLVO; Quartz crystal microbalance
Institution: The University of Sheffield
Academic Units: The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Chemical and Process Engineering (Sheffield)
The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield)
The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Civil and Structural Engineering (Sheffield)
Depositing User: Miss Anthea Tucker
Date Deposited: 07 Sep 2010 09:55
Last Modified: 08 Feb 2013 17:01
Published Version: http://dx.doi.org/10.1016/j.bbamem.2010.05.024
Status: Published
Publisher: Elsevier
Refereed: Yes
Identification Number: 10.1016/j.bbamem.2010.05.024
URI: http://eprints.whiterose.ac.uk/id/eprint/11204

Actions (repository staff only: login required)