title: Adsorption of fluorescently labeled protein residues on poly(ethylene-co-acrylic acid) films modified with affinity functionalities.
abstract: Poly(ethylene-co-acrylic acid) (EAA) films were reacted with glycine, 12-aminododecanoic acid, aspartic acid, 5-aminoisophthalic acid, ethanolamine, diethylamine, dimethylamine, N-isopropylamine, and dimethylaminoethyleneamine to prepare EAA films with negatively charged, non-charged, hydrophilic, and hydrophobic functionalities. Attenuated total reflectance Fourier transform infrared spectroscopy, differential scanning calorimetry, and contact angle measurements were used to characterize the modified EAA films. Analyses revealed that the films were modified on the surfaces and also in the bulk; therefore, bulk properties such as cohesive energy density were changed even though the surfaces remained hydrophobic. Adsorption studies were performed for two fluorescently labeled protein residues, dansyl-L-phenylalanine (dansyl-F) and dansyl-L-glutamine (dansyl-Q), from pH 7.4 buffer solutions. The adsorption results revealed that dimethylaminoethyleneamine functionality gave the highest uptake among the functionalities studied, and adsorption was more favorable for dansyl-F than dansyl-Q. Adsorption behavior is discussed in terms of hydrophobic-hydrophobic (dispersion) interactions and Coulombic interactions.
authors.affiliation: Department of Chemical and Biomolecular Engineering and the Center for Advanced Engineering Fibers and Films, Clemson University, Clemson, SC 29634-0909, United States.
authors.forename: Ning
authors.initials: N
authors.lastname: Luo
authors.forename: Chun
authors.initials: C
authors.lastname: Zhang
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Hirt
authors.forename: Scott M
authors.initials: SM
authors.lastname: Husson
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D000345:Affinity Labels; D001672:Biocompatible Materials / Q000737:chemistry*; D003619:Dansyl Compounds / Q000737:chemistry; D005456:Fluorescent Dyes; D005973:Glutamine / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D010649:Phenylalanine / Q000737:chemistry; D011095:Polyethylenes / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D000180:Acrylic Resins; D000345:Affinity Labels; D001672:Biocompatible Materials; D003619:Dansyl Compounds; D005456:Fluorescent Dyes; D011095:Polyethylenes; D011506:Proteins; C120199:dansyl-phenylalanine; D005973:Glutamine; D010649:Phenylalanine; C083316:(polyethylene-acrylic acid) copolymer