Effect of gold nanoparticles on the structure and electron-transfer characteristics of glucose oxidase redox polyelectrolyte-surfactant complexes

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.

Publication year: 2014
Authors: Cortez M.L. a,b, Marmisollé W. a, Pallarola D. b, Pietrasanta L.I. c, Murgida D.H. a, Ceolín M. b, Azzaroni O. b, Battaglini F. a

a – INQUIMAE – Departamento de Qui mica Inorog anica Anal itica y Qu imica F isica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CONICET, Argentina
b – Instituto de Investigaciones Fisicoquimicas Tas y Aplicades (INIFTA), Departmento de Quimica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CONICET, Argentina
c – Centro de Microscopias Avanzadas and Departmento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina

Published in: Chemistry - A European Journal, 2014, Vol. 20, Issue 41, p. 13037–13404
DOI: 10.1002/chem.201402707


amperometric biosensors composite surface electrochemistry enzyme mass glucose oxidase (GOx) adsorption polyelectrolyte-surfactant-AuNP


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