title: Structure and thickness dependence of "molecular wiring" in nanostructured enzyme multilayers.
abstract: Supramolecular organized multilayers composed of glucose oxidase (GOx) and osmium-derivatized poly(allylamine) redox polymer have been self-assembled electrostatically from Os-polyelectrolyte solutions of variable pH (5.5-8.8) leading to a decrease of the linear charge density in the PAH-Os with increasing pH. The layer-by-layer enzyme multilayers were studied by ellipsometry, quartz crystal microbalance, AFM, cyclic voltammetry, and electrocatalytic oxidation of beta-D-glucose. At higher adsorption solution pH, an increase in the film thickness, enzyme loading, and redox charge was observed. While the electrocatalytic response increases with the increase of the adsorption solution pH (decrease of the polyelectrolyte linear charge), the FADH2 oxidation bimolecular rate constant has a maximum in the pH range 7.0-7.5 where a change in the film growth mechanism is observed.
authors.affiliation: INQUIMAE, Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Victoria
authors.initials: V
authors.lastname: Flexer
authors.forename: Erica S
authors.initials: ES
authors.lastname: Forzani
authors.forename: Ernesto J
authors.initials: EJ
authors.lastname: Calvo
authors.forename: Silvio J
authors.initials: SJ
authors.lastname: Ludueña
authors.forename: Lia I
authors.initials: LI
authors.lastname: Pietrasanta
mesh_terms: D004563:Electrochemistry; D005947:Glucose / Q000378:metabolism; D005949:Glucose Oxidase / Q000737:chemistry* / Q000378:metabolism; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D009942:Organometallic Compounds / Q000737:chemistry; D009992:Osmium / Q000737:chemistry*; D010084:Oxidation-Reduction; D011073:Polyamines / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D011073:Polyamines; D009992:Osmium; C063994:polyallylamine; D005949:Glucose Oxidase; D005947:Glucose