Biofuel cell design electrodes

ELECTRICAL CONTACT OF REDOX ENZYMES WITH ELECTRODES FOR AMPEROMETRIC BIOSENSING AND BIOFUEL CELL DESIGN... 

RECONSTITUTED ENZYME-ELECTRODES FOR BIOFUEL CELL DESIGN... 

The design of biocatalytic electrodes for activity toward gaseous substrates, such as dioxygen or hydrogen, requires special consideration. An optimal electrode must balance transport in three different phases, namely, the gaseous phase (the source of substrate), the aqueous phase (where the product water is released and ionic transport takes place), and the solid phase (where electronic transport occurs). Whereas the selectivity of biocatalysts facilitates membraneless cells for implementation in biological systems that provide an ambient electrolyte, gas-diffusion biofuel cells require an electro-... 

Bioelectrocatalysis involves the coupling of redox enzymes with electrochemical reactions [44]. Thus, oxidizing enzymes can be incorporated into redox systems applied in bioreactors, biosensors and biofuel cells. While biosensors and enzyme electrodes are not synthetic systems, they are, essentially, biocatalytic in nature (Scheme 3.5) and are therefore worthy of mention here. Oxidases are frequently used as the biological agent in biosensors, in combinations designed to detect specific target molecules. Enzyme electrodes are possibly one of the more common applications of oxidase biocatalysts. Enzymes such as glucose oxidase or cholesterol oxidase can be combined with a peroxidase such as horseradish peroxidase. 

DET was also evidenced at SWCNT electrodes for other redox proteins such as hemoglobine [15], cytochrome C [11], microperoxydases [16] or catalases[17]. The ability of CNTs to achieve DET with enzymes has lead to the design of novel biofuel cell electrodes. 

Zayats, M., Willner, B., Willner, 1. Design of amperometric biosensors and biofuel cells by the reconstitution of electrically contacted enzyme electrodes. Electroanalysis 20(6), 583-601 (2008). doi 10.1002/elan.200704128... 

Despite the fact that enzyme-based biofuel cells progressed a lot in the last 20 years reaching the state where the electrodes operate in vivo being implanted in living organisms, the motivation for their design is not always clear. In most of the published papers the authors claim their use as a source of sustainable power extracted from renewable biological... 

Ackermann, Y., Guschin, D.A., Eckhard, K., Shleev, S., Schuhmann, W. Design of a bioelectrocatalytic electrode interface for oxygen reduction in biofuel cells based on a specifically adapted Os-complex containing redox polymer with entrapped Trametes hirsuta laccase. Electrochem. Commun. 2010,12, 640-643. 

Gooding JJ. Advances in intedacial design for electrochemical biosensors and sensors aryl diazonium salts for modifying carbon and metal electrodes. Electroanalysis 2008 20 573-582. Moehlenbrock MJ, Minteer SD. Extended lifetime biofuel cells. Chem Soc Rev 2008 37 1188-1196. 

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