title: Linker-free deposition and adhesion of Photosystem I onto nanostructured TiO2 for biohybrid photoelectrochemical cells.
abstract: Photosystem I (PSI) from oxygenic photosynthetic organisms is an attractive sensitizer for nano-biohybrid solar cells as it has a combined light-harvesting and reaction center in one protein complex and operates at a quantum yield close to one in biological systems. Using a linker-free deposition technique enabled by an electrospray system, PSI was coupled to 1-D nanostructured titanium dioxide thin films to fabricate an electrode for a photoelectrochemical cell. After deposition, the surfactant in the PSI aggregate was dissolved in the surfactant-free electrolyte, ensuring that partly hydrophobic PSI was not resuspended and stayed in contact with titanium dioxide. A maximum current density of 4.15 mA cm(-2) was measured after 10 min of electrospray deposition, and this is the highest current density reported so far for PSI-based photoelectrochemical cells. The high current is attributed to 1D nanostructure of titanium dioxide and orientation of the PSI onto the surface, which allows easy transfer of electrons.
authors.affiliation: Aerosol and Air Quality Research Laboratory, Department of Energy, Environmental and Chemical Engineering, ‡Departments of Biology and Chemistry, and §Photosynthetic Antenna Research Center, Washington University in St. Louis , St. Louis, Missouri 63130, United States.
authors.forename: Vivek B
authors.initials: VB
authors.lastname: Shah
authors.forename: William R
authors.initials: WR
authors.lastname: Henson
authors.forename: Tandeep S
authors.initials: TS
authors.lastname: Chadha
authors.forename: Gerard
authors.initials: G
authors.lastname: Lakin
authors.forename: Haijun
authors.initials: H
authors.lastname: Liu
authors.forename: Robert E
authors.initials: RE
authors.lastname: Blankenship
authors.forename: Pratim
authors.initials: P
authors.lastname: Biswas
mesh_terms: D065966:Absorption, Physicochemical; D000268:Adhesiveness; D004553:Electric Conductivity; D004563:Electrochemistry; D004579:Electron Transport; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry*; D055668:Photochemical Processes; D045331:Photosystem I Protein Complex / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D045331:Photosystem I Protein Complex; C009495:titanium dioxide; D014025:Titanium