title: Efficient Photoelectrochemical Energy Conversion using Spinach Photosystem II (PSII) in Lipid Multilayer Films.
abstract: The need for clean, renewable energy has fostered research into photovoltaic alternatives to silicon solar cells. Pigment-protein complexes in green plants convert light energy into chemical potential using redox processes that produce molecular oxygen. Here, we report the first use of spinach protein photosystem II (PSII) core complex in lipid films in photoelectrochemical devices. Photocurrents were generated from PSII in a ∼2 μm biomimetic dimyristoylphosphatidylcholine (DMPC) film on a pyrolytic graphite (PG) anode with PSII embedded in multiple lipid bilayers. The photocurrent was ∼20 μA cm(-2) under light intensity 40 mW cm(-2). The PSII-DMPC anode was used in a photobiofuel cell with a platinum black mesh cathode in perchloric acid solution to give an output voltage of 0.6 V and a maximum output power of 14 μW cm(-2). Part of this large output is related to a five-unit anode-cathode pH gradient. With catholytes at higher pH or no perchlorate, or using an MnO2 oxygen-reduction cathode, the power output was smaller. The results described raise the possibility of using PSII-DMPC films in small portable power conversion devices.
authors.affiliation: Department of Chemistry and Green Emulsions, Micelles, & Surfactants (GEMS) Center, University of Connecticut 55 N. Eagleville Rd, Storrs, CT, 06269-3060, USA.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Green Emulsions, Micelles, & Surfactants (GEMS) Center, University of Connecticut 55 N. Eagleville Rd, Storrs, CT, 06269-3060, USA.
authors.forename: Nikki M
authors.initials: NM
authors.lastname: Magdaong
authors.affiliation: Department of Chemistry and Green Emulsions, Micelles, & Surfactants (GEMS) Center, University of Connecticut 55 N. Eagleville Rd, Storrs, CT, 06269-3060, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Shen
authors.affiliation: Department of Chemistry and Green Emulsions, Micelles, & Surfactants (GEMS) Center, University of Connecticut 55 N. Eagleville Rd, Storrs, CT, 06269-3060, USA.
authors.forename: Harry A
authors.initials: HA
authors.lastname: Frank
authors.affiliation: Department of Chemistry and Green Emulsions, Micelles, & Surfactants (GEMS) Center, University of Connecticut 55 N. Eagleville Rd, Storrs, CT, 06269-3060, USA ; Institute of Materials Science, University of Connecticut 97 N. Eagleville Rd, Storrs, CT, 06269-3136, USA ; Department of Cell Biology, University of Connecticut Health Center 263 Farmington Ave, Farmington, CT, 06032, USA.
authors.forename: James F
authors.initials: JF
authors.lastname: Rusling
keywords: clean energy; lipid films; natural products; photoelectrochemistry; photosystem II