title: Tuning Structural Changes in Glucose Oxidase for Enzyme Fuel Cell Applications.
abstract: Stabilization and electrical contacting of redox enzymes with electrodes are fundamental requirements for bioelectronics devices, including biosensors and enzyme fuel cells (EFCs). In this study, we show increased glucose oxidase (GOx) stability by immobilization with Nafion. The immobilization process affected GOx conformation but was not detrimental to its activity, which was maintained for more than 120 days. The GOx/Nafion system was interfaced to a carbon cloth electrode and assembled in a prototypal EFC fed with glucose. Polarization and power density curves demonstrated that GOx/Nafion system was able to generate power, exploiting a Nafion-assisted electron transfer process to the electrode. Our findings are consistent with the onset of pH-dependent conformational equilibrium for the enzyme secondary structure and its active site. Significantly, the protective effect exerted by Nafion on the enzyme structure may be tuned by varying parameters such as the pH to fabricate durable EFCs with good electrocatalytic performance.
authors.affiliation: Department of Chemical Science and Technologies, University of Rome "Tor Vergata" , Via della Ricerca Scientifica, 00133 Rome, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Mecheri
authors.affiliation: Department of Chemical Science and Technologies, University of Rome "Tor Vergata" , Via della Ricerca Scientifica, 00133 Rome, Italy.
authors.forename: Diana
authors.initials: D
authors.lastname: De Porcellinis
authors.affiliation: School of Arts, Sciences and Humanities, University of São Paulo , Av. Arlindo Bettio, 1000, São Paulo CEP 03828-000, São Paulo, Brazil.
authors.forename: Patricia T
authors.initials: PT
authors.lastname: Campana
authors.affiliation: Università Campus Bio-Medico di Roma , Via Álvaro del Portillo 21, 00128 Rome, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Rainer
authors.affiliation: Università Campus Bio-Medico di Roma , Via Álvaro del Portillo 21, 00128 Rome, Italy.
authors.forename: Marcella
authors.initials: M
authors.lastname: Trombetta
authors.affiliation: Institute of Physics, Federal University of Uberlândia , Avenida João Naves de Ávila, 2121, Uberlândia, CEP 38408-100, Minas Gerais, Brazil.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Marletta
authors.affiliation: São Carlos Institute of Physics, University of São Paulo , CP 369, São Carlos 13560-970, São Paulo, Brazil.
authors.forename: Osvaldo N
authors.initials: ON
authors.lastname: Oliveira
authors.affiliation: Department of Chemical Science and Technologies, University of Rome "Tor Vergata" , Via della Ricerca Scientifica, 00133 Rome, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Licoccia
mesh_terms: D001674:Bioelectric Energy Sources; D004560:Electricity; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D005949:Glucose Oxidase / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D005949:Glucose Oxidase
keywords: Nafion; enzymatic fuel cells; enzyme activity; enzyme secondary structure; glucose oxidase