title: Photocurrent generation from Ru(bpy)3(2+) immobilized on phospholipid/alkanethiol hybrid bilayers.
abstract: A new photocurrent-generation system based on Ru(bpy)3(2+) (bpy=2,2'-bipyridine) tethered on phospholipid/alkanethiol hybrid bilayers in aqueous media is reported. The construction of such a system is straightforward. First, a self-assembled monolayer (SAM) of alkanethiol is formed on gold, and separately, liposomes containing Ru(bpy)3(2+)-conjugated dioleoylphosphoethanolamine (DOPE) are prepared by extrusion. Subsequent exposure of the Ru(bpy)3(2+)-containing liposome solution to the preformed SAM induces the addition of a monolayer of phospholipids on top of the SAM and thereby the immobilization of a Ru(bpy)3(2+) layer on the gold electrode. Either anodic or cathodic photocurrent generation can be obtained, when ascorbate (anodic) or methyl violgen/oxygen (cathodic) is used as a sacrificial electron donor/acceptor, respectively. Light conversion quantum efficiencies of 0.84% (anodic) and 0.21% (cathodic) were obtained under blue light (lambda=470+/-20 nm) irradiation. The photocurrent-generation and electron-transfer mechanisms of this new system as well as its potential usefulness in fundamental photoconversion studies are discussed.
authors.affiliation: Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Jiang
authors.forename: Hong
authors.initials: H
authors.lastname: Xie
authors.forename: Wei
authors.initials: W
authors.lastname: Zhan
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry*; D000473:Alkanes / Q000737:chemistry*; D025802:Electric Capacitance; D004553:Electric Conductivity; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry; D008567:Membranes, Artificial; D010713:Phosphatidylcholines / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: C410262:1,2-dioleoyl-glycero-3-phosphatidyl ethanolamine; D000473:Alkanes; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D013438:Sulfhydryl Compounds; D015082:2,2'-Dipyridyl; D006046:Gold; D012428:Ruthenium; C028694:1-palmitoyl-2-oleoylphosphatidylcholine