title: Non-invasive vibrational SFG spectroscopy reveals that bacterial adhesion can alter the conformation of grafted "brush" chains on SAM.
abstract: Understanding bacterial adhesion on a surface is a crucial step to design new materials with improved properties or to control biofilm formation and eradication. Sum Frequency Generation (SFG) vibrational spectroscopy has been employed to study in situ the conformational response of a self-assembled monolayer (SAM) of octadecanethiol (ODT) on a gold film to the adhesion of hydrophilic and hydrophobic ovococcoid model bacteria. The present work highlights vibrational SFG spectroscopy as a powerful and unique non-invasive biophysical technique to probe and control bacteria interaction with ordered surfaces. Indeed, the SFG vibrational spectral changes reveal different ODT SAM conformations in air and upon exposure to aqueous solution or bacterial adhesion. Furthermore, this effect depends on the bacterial cell surface properties. The SFG spectral modeling demonstrates that hydrophobic bacteria flatten the ODT SAM alkyl chain terminal part, whereas the hydrophilic ones raise this ODT SAM terminal part. Microorganism-induced alteration of grafted chains can thus affect the desired interfacial functionality, a result that should be considered for the design of new reactive materials.
authors.affiliation: Institut des Sciences Moléculaires d'Orsay, ISMO-CNRS, Université Paris Sud, Bât. 350 91405 Orsay cedex, France. emilie.bulard@u-psud.fr
authors.forename: Emilie
authors.initials: E
authors.lastname: Bulard
authors.forename: Ziang
authors.initials: Z
authors.lastname: Guo
authors.forename: Wanquan
authors.initials: W
authors.lastname: Zheng
authors.forename: Henri
authors.initials: H
authors.lastname: Dubost
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Fontaine-Aupart
authors.forename: Marie-Noëlle
authors.initials: MN
authors.lastname: Bellon-Fontaine
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Herry
authors.forename: Romain
authors.initials: R
authors.lastname: Briandet
authors.forename: Bernard
authors.initials: B
authors.lastname: Bourguignon
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D001422:Bacterial Adhesion / Q000187:drug effects*; D057927:Hydrophobic and Hydrophilic Interactions; D008968:Molecular Conformation; D013055:Spectrophotometry, Infrared; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D000473:Alkanes; D013438:Sulfhydryl Compounds; C022883:octadecane