Hybrid Carbon-Metal Nanowires Mediating Direct Electron Transfer from Redox Enzyme to Electrode

The electron transferring unit of enzymes – apoenzyme and cofactor are deeply buried inside its protein structure, therefore efficient electronic communication between the electrode and the biocatalytic enzyme is inefficient. The development of a reproducible approach that allows efficient electronic connection between enzymes and electrodes would meet the major technical needs in the development of manufacturable biological fuel cell technology. Luna Innovations proposes to use carbon nanospheres to build conductive hybrid nanowires that plug into the depth of enzymes in close proximity with the redox center. This approach not only promotes direct electron transfer from redox centers to nanowires due to the plugging orientation and the unparallel electron-accepting capability of fullerene nanospheres, but also is capable of transporting electrons released from enzymes to electrodes as the nanowire is vertically aligned and immobilized on the electrode. In Phase I, Luna will prepare nanowire-modified electrodes by assembling nanowires onto electrodes from nanosphere building blocks with a capable-of-being-automated method, plug the free ends of nanowires into enzymes, evaluate the device performance (electron transfer rates and current density), and identify parameters to be optimized in a biological fuel cell prototype in Phase II. BENEFIT: The nanowire approach for efficient electron transfer from enzymes to electrodes developed in Phase I would find use in the development of sensing and energy conversion technology, especially in the field of biological fuel cells. The demand for fuel cell products from both military and commercial sectors is dramatically increasing. Fuel cells are favored for distributed power generation, on-site power plants, portable electronics, and motor vehicle power etc. It can power modest-power demand devices. Reliability is critical for military power supply. Biological fuel cells have the advantages of low-cost, ultra-cleanness and without interruption, which can’t be offered by alternative energies relying on sunshine, wind and etc. With success, this proposed program will have huge impact on both military and commercial energy consumers with lower cost and more reliability.