title: Effect of gold nanoparticles on the structure and electron-transfer characteristics of glucose oxidase redox polyelectrolyte-surfactant complexes.
abstract: Efficient electrical communication between redox proteins and electrodes is a critical issue in the operation and development of amperometric biosensors. The present study explores the advantages of a nanostructured redox-active polyelectrolyte-surfactant complex containing [Os(bpy)2Clpy](2+) (bpy=2,2'-bipyridine, py= pyridine) as the redox centers and gold nanoparticles (AuNPs) as nanodomains for boosting the electron-transfer propagation throughout the assembled film in the presence of glucose oxidase (GOx). Film structure was characterized by grazing-incidence small-angle X-ray scattering (GISAXS) and atomic force microscopy (AFM), GOx incorporation was followed by surface plasmon resonance (SPR) and quartz-crystal microbalance with dissipation (QCM-D), whereas Raman spectroelectrochemistry and electrochemical studies confirmed the ability of the entrapped gold nanoparticles to enhance the electron-transfer processes between the enzyme and the electrode surface. Our results show that nanocomposite films exhibit five-fold increase in current response to glucose compared with analogous supramolecular AuNP-free films. The introduction of colloidal gold promotes drastic mesostructural changes in the film, which in turn leads to a rigid, amorphous interfacial architecture where nanoparticles, redox centers, and GOx remain in close proximity, thus improving the electron-transfer process.
authors.affiliation: INQUIMAE - Departamento de Química Inorgánica Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CONICET, Ciudad Universitaria, Pabellón 2, C1428EHA Buenos Aires (Argentina); Instituto de Investigaciones Fisicoquímicas Tas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CONICET, CC 16 Suc. 4 (1900) La Plata (Argentina).
authors.forename: M Lorena
authors.initials: ML
authors.lastname: Cortez
authors.forename: Waldemar
authors.initials: W
authors.lastname: Marmisollé
authors.forename: Diego
authors.initials: D
authors.lastname: Pallarola
authors.forename: Lía I
authors.initials: LI
authors.lastname: Pietrasanta
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Murgida
authors.forename: Marcelo
authors.initials: M
authors.lastname: Ceolín
authors.forename: Omar
authors.initials: O
authors.lastname: Azzaroni
authors.forename: Fernando
authors.initials: F
authors.lastname: Battaglini
mesh_terms: D055162:Biocatalysis; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry*; D004579:Electron Transport; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry; D005947:Glucose / Q000737:chemistry / Q000378:metabolism; D005949:Glucose Oxidase / Q000737:chemistry* / Q000378:metabolism; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D009992:Osmium / Q000737:chemistry; D010084:Oxidation-Reduction; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D004573:Electrolytes; D013501:Surface-Active Agents; D005182:Flavin-Adenine Dinucleotide; D009992:Osmium; D006046:Gold; D005949:Glucose Oxidase; D005947:Glucose
keywords: electron transfer; glucose catalysis; glucose oxidase; gold nanoparticles; mesostructure; redox polyelectrolyte