title: Layer-by-layer self-assembly of glucose oxidase and Os(Bpy)2CIPyCH2NH-poly(allylamine) bioelectrode.
abstract: The uptake of glucose oxidase (GOx) onto a polycationic redox polymer (PAA-Os)-modified surface, by adsorption from dilute aqueous GOx solutions, was followed by the quartz crystal microbalance (QCM) and shows double exponential kinetics. The electrochemistry of the layer-by-layer-deposited redox-active polymer was followed by cyclic voltammetry in glucose-free solutions, and the enzyme catalysis mediated by the redox polymer was studied in beta-D-glucose-containing solutions. AFM studies of the different layers showed the existence of large two dimension enzyme aggregates on the osmium polymer for 1 microM GOx and less aggregation for 50 nM GOx solutions. When the short alkanethiol, 2,2'-diaminoethyldisulfide was preadsorbed onto gold, a monoexponential adsorption law was observed, and single GOx enzyme molecules could be seen on the surface where the enzyme was adsorbed from 50 nM GOx in water.
authors: INQUIMAE, Departamento de Química Inorgánica, Analítica  y Química Física, Facultad de Ciencias Exactas y Naturales, Pabellón 2 Ciudad Universitaria, Buenos Aires, Argentina.
authors: E J
authors: EJ
authors: Calvo
authors: R
authors: R
authors: Etchenique
authors: L
authors: L
authors: Pietrasanta
authors: A
authors: A
authors: Wolosiuk
authors: C
authors: C
authors: Danilowicz
mesh_terms: D015374:Biosensing Techniques; D004563:Electrochemistry; D005949:Glucose Oxidase / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D009942:Organometallic Compounds; C425743:Os(Bpy)2CIPyCH2NH-poly(allylamine); D005949:Glucose Oxidase