title: Resistance of galactoside-terminated alkanethiol self-assembled monolayers to marine fouling organisms.
abstract: Self-assembled monolayers (SAMs) of galactoside-terminated alkanethiols have protein-resistance properties which can be tuned via the degree of methylation [Langmuir 2005, 21, 2971-2980]. Specifically, a partially methylated compound was more resistant to nonspecific protein adsorption than the hydroxylated or fully methylated counterparts. We investigate whether this also holds true for resistance to the attachment and adhesion of a range of marine species, in order to clarify to what extent resistance to protein adsorption correlates with the more complex adhesion of fouling organisms. The partially methylated galactoside-terminated SAM was further compared to a mixed monolayer of ω-substituted methyl- and hydroxyl-terminated alkanethiols with wetting properties and surface ratio of hydroxyl to methyl groups matching that of the galactoside. The settlement (initial attachment) and adhesion strength of four model marine fouling organisms were investigated, representing both micro- and macrofoulers; two bacteria (Cobetia marina and Marinobacter hydrocarbonoclasticus), barnacle cypris larvae (Balanus amphitrite), and algal zoospores (Ulva linza). The minimum in protein adsorption onto the partially methylated galactoside surface was partly reproduced in the marine fouling assays, providing some support for a relationship between protein resistance and adhesion of marine fouling organisms. The mixed alkanethiol SAM, which was matched in wettability to the partially methylated galactoside SAM, consistently showed higher settlement (initial attachment) of test organisms than the galactoside, implying that both wettability and surface chemistry are insufficient to explain differences in fouling resistance. We suggest that differences in the structure of interfacial water may explain the variation in adhesion to these SAMs.
authors.affiliation: Division of Molecular Physics, IFM, Linköping University, SE-581 83 Linköping, Sweden. ted@ifm.liu.se
authors.forename: Thomas
authors.initials: T
authors.lastname: Ederth
authors.forename: Tobias
authors.initials: T
authors.lastname: Ekblad
authors.forename: Michala E
authors.initials: ME
authors.lastname: Pettitt
authors.forename: Sheelagh L
authors.initials: SL
authors.lastname: Conlan
authors.forename: Chun-Xia
authors.initials: CX
authors.lastname: Du
authors.forename: Maureen E
authors.initials: ME
authors.lastname: Callow
authors.forename: James A
authors.initials: JA
authors.lastname: Callow
authors.forename: Robert
authors.initials: R
authors.lastname: Mutton
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Clare
authors.forename: Fraddry
authors.initials: F
authors.lastname: D'Souza
authors.forename: Glen
authors.initials: G
authors.lastname: Donnelly
authors.forename: Anouk
authors.initials: A
authors.lastname: Bruin
authors.forename: Peter R
authors.initials: PR
authors.lastname: Willemsen
authors.forename: Xueju J
authors.initials: XJ
authors.lastname: Su
authors.forename: Su
authors.initials: S
authors.lastname: Wang
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhao
authors.forename: Markus
authors.initials: M
authors.lastname: Hederos
authors.forename: Peter
authors.initials: P
authors.lastname: Konradsson
authors.forename: Bo
authors.initials: B
authors.lastname: Liedberg
mesh_terms: D000327:Adsorption; D000818:Animals; D059001:Aquatic Organisms / Q000187:drug effects / Q000502:physiology*; D001422:Bacterial Adhesion / Q000187:drug effects; D057219:Biofouling / Q000517:prevention & control*; D002448:Cell Adhesion / Q000187:drug effects; D005697:Galactosides / Q000737:chemistry* / Q000494:pharmacology; D044129:Halomonadaceae / Q000187:drug effects / Q000502:physiology; D013438:Sulfhydryl Compounds / Q000737:chemistry* / Q000494:pharmacology; D013499:Surface Properties; D001468:Thoracica / Q000187:drug effects / Q000502:physiology; D044445:Ulva / Q000187:drug effects / Q000502:physiology
chemical_list: D005697:Galactosides; D013438:Sulfhydryl Compounds