title: Covalent immobilization of oriented photosystem II on a nanostructured electrode for solar water oxidation.
abstract: Photosystem II (PSII) offers a biological and sustainable route of photochemical water oxidation to O2 and can provide protons and electrons for the generation of solar fuels, such as H2. We present a rational strategy to electrostatically improve the orientation of PSII from a thermophilic cyanobacterium, Thermosynechococcus elongatus , on a nanostructured indium tin oxide (ITO) electrode and to covalently immobilize PSII on the electrode. The ITO electrode was modified with a self-assembled monolayer (SAM) of phosphonic acid ITO linkers with a dangling carboxylate moiety. The negatively charged carboxylate attracts the positive dipole on the electron acceptor side of PSII via Coulomb interactions. Covalent attachment of PSII in its electrostatically improved orientation to the SAM-modified ITO electrode was accomplished via an amide bond to further enhance red-light-driven, direct electron transfer and stability of the PSII hybrid photoelectrode.
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
authors.forename: Masaru
authors.initials: M
authors.lastname: Kato
authors.forename: Tanai
authors.initials: T
authors.lastname: Cardona
authors.forename: A William
authors.initials: AW
authors.lastname: Rutherford
authors.forename: Erwin
authors.initials: E
authors.lastname: Reisner
mesh_terms: D000458:Cyanobacteria / Q000201:enzymology*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry*; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry*; D010084:Oxidation-Reduction; D045332:Photosystem II Protein Complex / Q000737:chemistry*; D012993:Solar Energy; D055672:Static Electricity; D017971:Tin Compounds / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D045332:Photosystem II Protein Complex; D017971:Tin Compounds; D014867:Water; C109984:indium tin oxide