(336l) Biofuel Cell Using Glucose Oxidase and Screen Printing Process

Biofuel cells are of great interest in alternative energy and miniaturization applications such as portable energy supplies, pacemakers, and glucose sensors. Biofuel cells can be constructed with enzymes and\or microorganisms. The most common biofuel cell uses glucose oxidase to produce electrons from the glucose to gluconic acid chemical reaction. The electrical potential of glucose oxidase for converting glucose to gluconic acid is 0.75V. Many researchers have developed methods to immobilize glucose oxidase enzymes onto different electrode surfaces; thus creating a fuel cell that could provide power in biological applications. There are some promising results; however, the disadvantages of the current methods are low power output and short electrode lifetime due to enzyme denaturization and product inhibition. Utilizing the high conductivity of carbon nanotubes (CNT) (>1000 X more conductive than copper), this paper modifies the surface of CNTs and covalently binds with glucose oxidase enzymes. With the high conductivity structure and stabilized enzyme immobilization, this paper explores electrical output and electrode lifetime in comparison with previous studies. Further, our studies look at using ion exchange mechanisms to remove products and extend lifetimes further. The optimal enzyme loading per mass of the CNT will be presented. Further, the paper provides a unique approach to screen printing miniaturization for use in mass production of biofuel cells with CNT and ion exchange functionality. Electric power is evaluated based on geometry and the area of active electron transfer surface. The results give a comprehensive view of the optimal design for a miniaturized bioelectrode, especially using a screen printing miniaturization process.