(676e) Tuning Electrochemical Performances of Glucose Oxidase Nanocomposites By Changing the Shape and Surface Properties of Carbon Support Materials

The use of carbon nanoparticles as enzyme support to create enzymatic nanocomposites for biofuel cell applications has been extensively investigated. However, little is known about the effect of the carbonaceous nanomaterials’ morphology and surface chemistry on the electrochemical performance of cross-linked glucose oxidase (GOx) aggregate nanocomposites. The objective of this paper is to compare the effect of the properties of multiwalled carbon nanotubes (CNTs) and graphitized mesoporous carbons (GMCs) on the electrochemical performance of GOx-nanocomposites. These materials were chosen due to their very contrasting shapes, and consequently, their vastly different aggregate morphologies. Four different nanocomposites were prepared combining cross-linked GOx aggregates with acid treated GMC, as-received GMC, and acid treated CNTs. The graphitization index and oxygen functionalities on the surface of the nanocarbons were studied by using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The performance and structure of the nano-composites obtained were studied by thermal shock, elemental analysis, cyclic voltammetry, potentiostatic tests, confocal microscopy, and transmission electron microscopy. It was observed that enzyme loading is improved by the acid treatment of the carbon nanomaterials. Our results also show that the morphology and bulk properties of the carbon structures determine the electrochemical performance of the GOx-nanocomposites. The best power density of a biofuel cell without a mediator prepared using the nanocomposites as biocatalyst in the anode was obtained for the nanocomposites produced with cross-linked GOx-aggregates and acid treated GMC.