title: Entrapping cross-linked glucose oxidase aggregates within a graphitized mesoporous carbon network for enzymatic biofuel cells.
abstract: This paper reports a novel method for producing glucose oxidase-nanocomposites by entrapping cross-linked glucose oxidase (GOx) aggregates within a graphitized mesoporous carbon (GMC) network. Entrapment was achieved by utilizing the strong self-aggregation tendency of GMC in aqueous buffer solution to form carbon networks. Using confocal microscopy and TEM, GOx-GMC nanocomposites were visualized. The electrochemical properties of GOx-GMC nanocomposites were studied by means of cyclic voltammograms, chronoamperometric and potentiostatic tests. Results therefrom suggested that the GOx-GMC nanocomposites offer a high electrical conductivity with the maximum electron transfer rate constant estimated at 5.16±0.61s(-1). Furthermore, thermally treating the GOx-GMC nanocomposite and GOx aggregates at 60°C for four hours, both samples maintained 99% of their initial activity, while the free GOx were completely deactivated. These performances suggested that our nanocomposite structure offered both improved electrochemical performance and stability by combining the high electrical conductivity offered by the GMC network with the high enzyme loading and stability offered by the cross-linked GOx aggregates. The GOx-GMC nanocomposite's electrochemical activity towards glucose oxidation was also investigated by using an enzymatic biofuel cell without artificial mediators, producing a power density of up to 22.4μWcm(-2) at 0.24V.
authors.affiliation: School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA.
authors.forename: Tsai
authors.initials: T
authors.lastname: Garcia-Perez
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Sung-Gil
authors.initials: SG
authors.lastname: Hong
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea. Electronic address: jbkim3@korea.ac.kr.
authors.forename: Jungbae
authors.initials: J
authors.lastname: Kim
authors.affiliation: School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA. Electronic address: suha@wsu.edu.
authors.forename: Su
authors.initials: S
authors.lastname: Ha
mesh_terms: D001674:Bioelectric Energy Sources; D001709:Biotechnology; D003432:Cross-Linking Reagents; D004563:Electrochemistry; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D005949:Glucose Oxidase / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D066329:Protein Aggregates
chemical_list: D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D066329:Protein Aggregates; D006108:Graphite; D005949:Glucose Oxidase
keywords: Cross-linked glucose oxidase aggregates; Efficient electron transfer; Enzymatic biofuel cells; Glucose oxidase; Graphitized mesoporous carbons