Photosystem I – Based biohybrid photoelectrochemical cells

• Published in: Bioresource technology 2010-05, Vol.101 (9), p.3047-3053
• Main Authors: Ciesielski, Peter N., Hijazi, Frederick M., Scott, Amanda M., Faulkner, Christopher J., Beard, Lisa, Emmett, Kevin, Rosenthal, Sandra J., Cliffel, David, Kane Jennings, G.
• Format: Article
• Language: English
• Subjects: Biocatalysis - radiation effects; Bioelectric Energy Sources; Bioelectronics; Biological and medical sciences; Density; Devices; Direct power generation; Electric potential; Electricity; electrochemistry; Electrodes; Electrolytic cells; Electrons; energy conversion; energy transfer; Fundamental and applied biological sciences. Psychology; Light; Models, Molecular; Photocatalysis; Photochemistry - instrumentation; Photocurrent; Photoelectric effect; Photoelectrochemical cells; photosynthesis; photosystem I; Photosystem I Protein Complex - chemistry; Photosystem I Protein Complex - metabolism; Plants - metabolism; Plants - radiation effects; solar energy; solar radiation
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2009.12.045

Photosynthesis is the process by which Nature coordinates a tandem of protein complexes of impressive complexity that function to harness staggering amounts of solar energy on a global scale. Advances in biochemistry and nanotechnology have provided tools to isolate and manipulate the individual components of this process, thus opening a door to a new class of highly functional and vastly abundant biological resources. Here we show how one of these components, Photosystem I (PSI), is incorporated into an electrochemical system to yield a stand-alone biohybrid photoelectrochemical cell that converts light energy into electrical energy. The cells make use of a dense multilayer of PSI complexes assembled on the surface of the cathode to produce a photocatalytic effect that generates photocurrent densities of ∼2 μA/cm 2 at moderate light intensities. We describe the relationship between the current and voltage production of the cells and the photoinduced interactions of PSI complexes with electrochemical mediators, and show that the performance of the present device is limited by diffusional transport of the electrochemical mediators through the electrolyte. These biohybrid devices display remarkable stability, as they remain active in ambient conditions for at least 280 days. Even at bench-scale production, the materials required to fabricate the cells described in this manuscript cost ∼10 cents per cm 2 of active electrode area.