Linker-Free Deposition and Adhesion of Photosystem I onto Nanostructured TiO2 for Biohybrid Photoelectrochemical Cells

• Published in: Langmuir Vol. 31; no. 5; pp. 1675 - 1682
• Main Authors: Shah, Vivek B, Henson, William R, Chadha, Tandeep S, Lakin, Gerard, Liu, Haijun, Blankenship, Robert E, Biswas, Pratim
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 10-02-2015
• Subjects: Absorption, Physicochemical; Adhesiveness; Electric Conductivity; Electrochemistry; Electron Transport; Models, Molecular; Molecular Conformation; Nanostructures - chemistry; Photochemical Processes; Photosystem I Protein Complex - chemistry; Surface Properties; Titanium - chemistry
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la503776b

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.