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

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 Quimica Inoroganica Analitica y Quimica Fisica, 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

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.

MP-SPR keywords: amperometric biosensors, composite surface, electrochemistry, enzyme mass, glucose oxidase (GOx) adsorption, polyelectrolyte-surfactant-AuNP