title: Interfacial structure of a DOPA-inspired adhesive polymer studied by sum frequency generation vibrational spectroscopy.
abstract: Marine mussels deposit adhesive proteins containing 3,4-dihydroxyphenylalanine (DOPA) to attach themselves to different surfaces. Isolating such proteins from biological sources for adhesion purposes tends to be challenging. Recently, a simplified synthetic adhesive polymer, poly[(3,4-dihydroxystyrene)-co-styrene] (PDHSS), was developed to mimic DOPA-containing proteins. The pendant catechol group in this polymer provides cross-linking and adhesion much like mussel proteins do. In this work, sum frequency generation (SFG) vibrational spectroscopy was applied to reveal the structures of this DOPA-inspired polymer at air, water, and polymer interfaces. SFG spectroscopy results showed that when underwater, the catechol rings and the quinone rings were ordered, ready to adhere to surfaces. At the hydrophobic polystyrene interface, benzene π-π stacking is likely the adhesive force, whereas at the hydrophilic poly(allylamine) interface, primary amines may form hydrogen bonds with catechol or react with quinones for adhesion.
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States.
authors.forename: Chuan
authors.initials: C
authors.lastname: Leng
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Liu
authors.forename: Courtney
authors.initials: C
authors.lastname: Jenkins
authors.forename: Heather
authors.initials: H
authors.lastname: Meredith
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Wilker
authors.forename: Zhan
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000269:Adhesives / Q000737:chemistry*; D000388:Air; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D049872:Bivalvia; D004295:Dihydroxyphenylalanine / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D018716:Molecular Mimicry; D011073:Polyamines / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry*; D013499:Surface Properties; D014867:Water
chemical_list: D000269:Adhesives; D001672:Biocompatible Materials; D011073:Polyamines; D011137:Polystyrenes; C575680:poly(3,4-dihydroxystyrene-co-styrene); D014867:Water; C063994:polyallylamine; D004295:Dihydroxyphenylalanine