title: Spin-Controlled Photoluminescence in Hybrid Nanoparticles Purple Membrane System.
abstract: Spin-dependent photoluminescence (PL) quenching of CdSe nanoparticles (NPs) has been explored in the hybrid system of CdSe NP purple membrane, wild-type bacteriorhodopsin (bR) thin film on a ferromagnetic (Ni-alloy) substrate. A significant change in the PL intensity from the CdSe NPs has been observed when spin-specific charge transfer occurs between the retinal and the magnetic substrate. This feature completely disappears in a bR apo membrane (wild-type bacteriorhodopsin in which the retinal protein covalent bond was cleaved), a bacteriorhodopsin mutant (D96N), and a bacteriorhodopsin bearing a locked retinal chromophore (isomerization of the crucial C13═C14 retinal double bond was prevented by inserting a ring spanning this bond). The extent of spin-dependent PL quenching of the CdSe NPs depends on the absorption of the retinal, embedded in wild-type bacteriorhodopsin. Our result suggests that spin-dependent charge transfer between the retinal and the substrate controls the PL intensity from the NPs.
authors.affiliation: Department of Chemical Physics and ‡Department of Organic Chemistry, Weizmann Institute , Rehovot 76100, Israel.
authors.forename: Partha
authors.initials: P
authors.lastname: Roy
authors.affiliation: Department of Chemical Physics and ‡Department of Organic Chemistry, Weizmann Institute , Rehovot 76100, Israel.
authors.forename: Nirit
authors.initials: N
authors.lastname: Kantor-Uriel
authors.affiliation: Department of Chemical Physics and ‡Department of Organic Chemistry, Weizmann Institute , Rehovot 76100, Israel.
authors.forename: Debabrata
authors.initials: D
authors.lastname: Mishra
authors.affiliation: Department of Chemical Physics and ‡Department of Organic Chemistry, Weizmann Institute , Rehovot 76100, Israel.
authors.forename: Sansa
authors.initials: S
authors.lastname: Dutta
authors.affiliation: Department of Chemical Physics and ‡Department of Organic Chemistry, Weizmann Institute , Rehovot 76100, Israel.
authors.forename: Noga
authors.initials: N
authors.lastname: Friedman
authors.affiliation: Department of Chemical Physics and ‡Department of Organic Chemistry, Weizmann Institute , Rehovot 76100, Israel.
authors.forename: Mordechai
authors.initials: M
authors.lastname: Sheves
authors.affiliation: Department of Chemical Physics and ‡Department of Organic Chemistry, Weizmann Institute , Rehovot 76100, Israel.
authors.forename: Ron
authors.initials: R
authors.lastname: Naaman
keywords: bacteriorhodopsin; charge transfer; energy transfer; photoluminescence; spin filtering