title: A glucose anode for enzymatic fuel cells optimized for current production under physiological conditions using a design of experiment approach.
abstract: This study reports a design of experiment methodology to investigate and improve the performance of glucose oxidizing enzyme electrodes. Enzyme electrodes were constructed by co-immobilization of amine-containing osmium redox complexes, multiwalled carbon nanotubes and glucose oxidase in a carboxymethyldextran matrix at graphite electrode surfaces to provide a 3-dimensional matrix for electrocatalytic oxidation of glucose. Optimization of the amount of the enzyme electrode components to produce the highest current density under pseudo-physiological conditions of 5 mM glucose in saline buffer at 37 °C was performed using response surface methodology. A statistical analysis showed that the proposed model had a good fit with the experimental results. From the validated model, the addition of multiwalled carbon nanotubes and carboxymethyldextran components was identified as major contributing factors to the improved performance. Based on the optimized amount of components, enzyme electrodes display current densities of 1.2±0.1 mA cm(-2) and 5.2±0.2 mA cm(-2) at 0.2 V vs. Ag/AgCl in buffer containing 5 mM and 100 mM glucose, respectively, largely consistent with the predicted values. This demonstrates that use of a design of experiment approach can be applied effectively and efficiently to improve the performance of enzyme electrodes as anodes for biofuel cell device development.
authors.affiliation: School of Chemistry & Ryan Institute, National University of Ireland Galway, University Road, Galway, Ireland.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Kumar
authors.affiliation: School of Chemistry & Ryan Institute, National University of Ireland Galway, University Road, Galway, Ireland. Electronic address: donal.leech@nuigalway.ie.
authors.forename: Dónal
authors.initials: D
authors.lastname: Leech
mesh_terms: D001674:Bioelectric Energy Sources; D004553:Electric Conductivity; D004563:Electrochemistry; D004566:Electrodes; D005947:Glucose / Q000737:chemistry*; D005949:Glucose Oxidase / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction
chemical_list: D005949:Glucose Oxidase; D005947:Glucose
keywords: Biofuel cell; Design of experiment; Glucose oxidation; Osmium mediator