Effect of Gold Nanoparticles on the Structure and Electron Transfer Characteristics of Glucose Oxidase-Redox Polyelectrolyte-Surfactant Complexes

CORTEZ M.L.; MARMISOLLÉ, W.A.; PALLAROLA, D.; PIETRASANTA, L.I.; MURGIDA D.H.; CEOLÍN, M.; AZZARONI, O.; BATTAGLINI, F.

CHEMISTRY-A EUROPEAN JOURNAL

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2014 vol. 20 p. 13366 - 13374

0947-6539

Efficient electrical communication between redox proteins and electrodes is a critical issue in the operation and development of amperometric biosensors. Emphasis should be given to fundamental studies aiming to exceed the limitations of conventional enzyme immobilization methods, which have a deleterious effect on enzymatic activity and suffer from limited enzyme loading capacity. The present study explores the advantages of nanostructured redox-active polyelectrolyte-surfactant composite materials as scaffold for the immobilization of functional proteins and the fabrication of highly sensitive amperometric biosensors. Our approach is based on a polyallylamine-dodecyl sulfate (PA-DS) complex containing [Os(bpy)2Clpy]2+ as redox centers and gold nanoparticles as conductive nanodomains for boosting the electron transfer propagation throughout the assembled film. Glucose oxidase (GOx) was incorporated to the patterned nanocomposite providing the biorecognition element for glucose sensing. Surface plasmon resonance (SPR) spectroscopy and quartz crystal microbalance with dissipation (QCM-D) studies were combined to give a close representation of the enzyme assembly process, while grazing incidence small-angle X-ray scattering (GISAXS) and atomic force microscopy (AFM) provided information about the film mesostructure and morphology. Raman spectroelectrochemistry and electrochemical studies confirmed the ability of the entrapped gold nanoparticles as enhancers of electron transfer processes between the enzyme and the electrode surface, leading to a 5-fold increase in glucose oxidation rate. The simplicity and effectiveness of this approach for effecting electrical wiring of redox enzymes should lend itself broadly to different amperometric-based biosensing strategies enhancing the capabilities and improving the reliability of sensing devices.