title: Impact of surface wettability on S-layer recrystallization: a real-time characterization by QCM-D.
abstract: Quartz crystal microbalance with dissipation monitoring (QCM-D) has been employed to study the assembly and recrystallization kinetics of isolated SbpA bacterial surface proteins onto silicon dioxide substrates of different surface wettability. Surface modification by UV/ozone oxidation or by vapor deposition of 1H,1H,2H,2H-perfluorododecyltrichlorosilane yielded hydrophilic or hydrophobic samples, respectively. Time evolution of frequency and dissipation factors, either individually or combined as the so-calledDfplots, showed a much faster formation of crystalline coatings for hydrophobic samples, characterized by a phase-transition peak at around the 70% of the total mass adsorbed. This behavior has been proven to mimic, both in terms of kinetics and film assembly steps, the recrystallization taking place on an underlying secondary cell-wall polymer (SCWP) as found in bacteria. Complementary atomic force microscopy (AFM) experiments corroborate these findings and reveal the impact on the final structure achieved.
authors.affiliation: Institute for Biophysics, Dept. of Nanobiotechnology, BOKU University for Natural Resources and Life Sciences, Muthgasse 11 (Simon Zeisel Haus), A-1190 Vienna, Austria.
authors.forename: Jagoba
authors.initials: J
authors.lastname: Iturri
authors.affiliation: Institute for Biophysics, Dept. of Nanobiotechnology, BOKU University for Natural Resources and Life Sciences, Muthgasse 11 (Simon Zeisel Haus), A-1190 Vienna, Austria; University of Sao Paulo (USP), Faculty of Philosophy, Science and Letters of Ribeirao Preto (FFCLRP), Department of Chemistry, Ribeirao Preto, SP, Brazil.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Vianna
authors.affiliation: Institute for Biophysics, Dept. of Nanobiotechnology, BOKU University for Natural Resources and Life Sciences, Muthgasse 11 (Simon Zeisel Haus), A-1190 Vienna, Austria.
authors.forename: Alberto
authors.initials: A
authors.lastname: Moreno-Cencerrado
authors.affiliation: Institute for Biophysics, Dept. of Nanobiotechnology, BOKU University for Natural Resources and Life Sciences, Muthgasse 11 (Simon Zeisel Haus), A-1190 Vienna, Austria.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Pum
authors.affiliation: Institute for Biophysics, Dept. of Nanobiotechnology, BOKU University for Natural Resources and Life Sciences, Muthgasse 11 (Simon Zeisel Haus), A-1190 Vienna, Austria.
authors.forename: Uwe B
authors.initials: UB
authors.lastname: Sleytr
authors.affiliation: Institute for Biophysics, Dept. of Nanobiotechnology, BOKU University for Natural Resources and Life Sciences, Muthgasse 11 (Simon Zeisel Haus), A-1190 Vienna, Austria.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Toca-Herrera
keywords: Quartz crystal microbalance with dissipation monitoring (QCM-D); bacterial S-layers; recrystallization kinetics; surface wettability