title: Optical and structural properties of protein/gold hybrid bio-nanofilms prepared by layer-by-layer method.
abstract: Lysozyme/gold thin layers were prepared by layer-by-layer (LbL) self-assembly method. The build-up of the films was followed by UV-vis-absorbance spectra, quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) techniques. The structural property of films was examined by X-ray diffraction (XRD) measurements, while their morphology was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). It was found that gold nanoparticles (NPs) had cubic crystalline structure, the primary particles form aggregates in the thin layer due to the presence of lysozyme molecules. The UV-vis measurements prove change in particle size while the colour of the film changes from wine-red to blue. The layer thickness of films was determined using the above methods and the loose, porous structure of the films explains the difference in the results. The vapour adsorption property of hybrid layers was also studied by QCM using different saturated vapours and ammonia gas. The lysozyme/Au films were most sensitive for ammonia gas among the tested gases/vapours due to the strongest interaction between the functional groups of the protein.
authors.affiliation: Department of Physical Chemistry and Materials Sciences, University of Szeged, Szeged, Hungary.
authors.forename: Edit
authors.initials: E
authors.lastname: Pál
authors.forename: Viktória
authors.initials: V
authors.lastname: Hornok
authors.forename: Dániel
authors.initials: D
authors.lastname: Sebok
authors.forename: Andrea
authors.initials: A
authors.lastname: Majzik
authors.forename: Imre
authors.initials: I
authors.lastname: Dékány
mesh_terms: D003460:Crystallization; D006046:Gold / Q000737:chemistry*; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009113:Muramidase / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D011506:Proteins / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods; D020349:Surface Plasmon Resonance; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D008567:Membranes, Artificial; D011506:Proteins; D006046:Gold; D009113:Muramidase