title: In Situ Infrared Ellipsometry for Protein Adsorption Studies on Ultrathin Smart Polymer Brushes in Aqueous Environment.
abstract: The protein-adsorbing and -repelling properties of various smart nanometer-thin polymer brushes containing poly(N-isopropylacrylamide) and poly(acrylic acid) with high potential for biosensing and biomedical applications are studied by in situ infrared-spectroscopic ellipsometry (IRSE). IRSE is a highly sensitive nondestructive technique that allows protein adsorption on polymer brushes to be investigated in an aqueous environment as external stimuli, such as temperature and pH, are varied. These changes are relevant to conditions for regulation of protein adsorption and desorption for biotechnology, biocatalysis, and bioanalytical applications. Here brushes are used as model surfaces for controlling protein adsorption of human serum albumin and human fibrinogen. The important finding of this work is that IRSE in the in situ experiments in protein solutions can distinguish between contributions of polymer brushes and proteins. The vibrational bands of the polymers provide insights into the hydration state of the brushes, whereas the protein-specific amide bands are related to changes of the protein secondary structure.
authors: ‡Leibniz-Institut für Analytische Wissenschaften - ISAS - e. V., Schwarzschildstraße 8, 12489 Berlin, Germany.
authors: Annika
authors: A
authors: Kroning
authors: ‡Leibniz-Institut für Analytische Wissenschaften - ISAS - e. V., Schwarzschildstraße 8, 12489 Berlin, Germany.
authors: Andreas
authors: A
authors: Furchner
authors: ‡Leibniz-Institut für Analytische Wissenschaften - ISAS - e. V., Schwarzschildstraße 8, 12489 Berlin, Germany.
authors: Dennis
authors: D
authors: Aulich
authors: §Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Straße 6, 01069 Dresden, Germany.
authors: Eva
authors: E
authors: Bittrich
authors: §Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Straße 6, 01069 Dresden, Germany.
authors: Sebastian
authors: S
authors: Rauch
authors: §Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Straße 6, 01069 Dresden, Germany.
authors: Petra
authors: P
authors: Uhlmann
authors: §Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Straße 6, 01069 Dresden, Germany.
authors: Klaus-Jochen
authors: KJ
authors: Eichhorn
authors: ⊥School of Materials Science and Engineering Clemson University, 161 Sirrine Hall, Clemson, South Carolina 29634-0971, United States.
authors: Michael
authors: M
authors: Seeber
authors: ⊥School of Materials Science and Engineering Clemson University, 161 Sirrine Hall, Clemson, South Carolina 29634-0971, United States.
authors: Igor
authors: I
authors: Luzinov
authors: ∥Departments of Chemistry and of Chemical Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States.
authors: S Michael
authors: SM
authors: Kilbey
authors: #Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
authors: Bradley S
authors: BS
authors: Lokitz
authors: ∇Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States.
authors: Sergiy
authors: S
authors: Minko
authors: ‡Leibniz-Institut für Analytische Wissenschaften - ISAS - e. V., Schwarzschildstraße 8, 12489 Berlin, Germany.
authors: Karsten
authors: K
authors: Hinrichs
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D049329:Nanostructures / Q000737:chemistry*; D011506:Proteins / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D013055:Spectrophotometry, Infrared / Q000379:methods*
chemical_list: D000180:Acrylic Resins; D011506:Proteins; C052970:poly-N-isopropylacrylamide; C006903:carbopol 940
keywords: in situ infrared ellipsometry; infrared spectroscopy; polymer brushes; protein adsorption; solid−liquid interface; stimuli-responsive