Grant: Strategic Projects - Group

Plants and photosynthetic bacteria harvest sunlight with incredibly high efficiencies and convert light energy to chemical potential energy. Can we benefit from nature's methods in order to generate electrical power? This proposal is to take an interdisciplinary approach to this question. The methods rely on genetic engineering and biochemical separation techniques, along with device modeling and fabrication techniques. The creation of new photosynthesis protein variants and development of biochemical methods, in combination with the modeling and fabrication skills has resulted in an opportunity to investigate and exploit the incredible solar to electrical energy conversion capabilities of naturally occurring proteins. The specific experiments will utilize proteins that naturally harvest light energy and convert this energy to a flow of electrons. In photosynthesis, this electron flow is immediately tapped in chemical reactions by other proteins in a living cell. In our work we will remove the proteins from the cell, such that the light-driven electron flow is diverted to a fabricated electrode and enters an electrical circuit, where it can be used to power devices. Work by others has shown the feasibility of this approach but currents and voltages have been much smaller than is theoretically possible. In our approach the efficient transfer of electrons from the protein to the electrode will be enhanced by developing the optimum combination of: 1) genetically engineered proteins, those surface properties are changed in geometrically and chemically precise ways; 2) mediators of charge storage and transfer between the protein and either a cathode or an anode; 3) electrodes designed to interact with either the cathode- or anode-specific mediator. The net result of this approach will be much more efficient movement of charges between the protein and the electrodes, and hence increased electrical current, as well as storage of electrical potential within the photocell. This technology has the potential to be inexpensive and appropriate for the relatively low light intensities found in many places in Canada. The storage capability will enable it to function effectively in remote, off power grid, communities that are numerous in this country.