Enzyme-based biofuel cells are attracting attention rapidly partially due to the promising advances reported recently. However, there are issues to be addressed before biofuel cells become competitive in practical applications. Two critical issues are short lifetime and poor power density, both of which are related to enzyme stability, electron transfer rate, and enzyme loading. Recent progress in nanobiocatalysis opens the possibility to improve in these aspects. Many nano-structured materials, such as mesoporous media, nanoparticles, nanofibers, and nanotubes, have been demonstrated as efficient hosts of enzyme immobilization. It is evident that, when nanostructure of conductive materials are used, the large surface area of these nanomaterials can increase the enzyme loading and facilitate reaction kinetics, and thus improving the power density of biofuel cells. In addition, research efforts have also been made to improve the activity and stability of immobilized enzymes by using nanostructures. It appears to be reasonable to us to expect that progress in nanostuctured biocatalysts will play a critical role in overcoming the major obstacles in the development of powerful biofuel cells.
Bibliographical noteFunding Information:
Jungbae Kim would like to thank the U.S. Department of Energy (DOE) for the Laboratory Directed Research and Development funds administrated by the Pacific Northwest National Laboratory (PNNL), and the DOE Office of Biological and Environmental Research under the Environmental Management Science Program. Ping Wang thanks support from NER program of the National Science Foundation (BES # 0103232).
- Biofuel cell
- Enzyme immobilization
- Enzyme stabilization