title: Induced chirality through electromagnetic coupling between chiral molecular layers and plasmonic nanostructures.
abstract: We report a new approach for creating chiral plasmonic nanomaterials. A previously unconsidered, far-field mechanism is utilized which enables chirality to be conveyed from a surrounding chiral molecular material to a plasmonic resonance of an achiral metallic nanostructure. Our observations break a currently held preconception that optical properties of plasmonic particles can most effectively be manipulated by molecular materials through near-field effects. We show that far-field electromagnetic coupling between a localized plasmon of a nonchiral nanostructure and a surrounding chiral molecular layer can induce plasmonic chirality much more effectively (by a factor of 10(3)) than previously reported near-field phenomena. We gain insight into the mechanism by comparing our experimental results to a simple electromagnetic model which incorporates a plasmonic object coupled with a chiral molecular medium. Our work offers a new direction for the creation of hybrid molecular plasmonic nanomaterials that display significant chiroptical properties in the visible spectral region.
authors.affiliation: School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors.forename: Nadia A
authors.initials: NA
authors.lastname: Abdulrahman
authors.forename: Z
authors.initials: Z
authors.lastname: Fan
authors.forename: Taishi
authors.initials: T
authors.lastname: Tonooka
authors.forename: Sharon M
authors.initials: SM
authors.lastname: Kelly
authors.forename: Nikolaj
authors.initials: N
authors.lastname: Gadegaard
authors.forename: Euan
authors.initials: E
authors.lastname: Hendry
authors.forename: Alexander O
authors.initials: AO
authors.lastname: Govorov
authors.forename: Malcolm
authors.initials: M
authors.lastname: Kadodwala
mesh_terms: D002942:Circular Dichroism; D004574:Electromagnetic Fields; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D008567:Membranes, Artificial; D009942:Organometallic Compounds