title: Embedded plasmonic nanomenhirs as location-specific biosensors.
abstract: We introduce a novel optical biosensing platform that exploits the asymmetry of nanostructures embedded in nanocavities, termed nanomenhirs. Upon oblique illumination using plane polarized white light, two plasmonic resonances attributable to the bases and the axes of the nanomenhirs emerge; these are used for location-specific sensing of membrane-binding events. Numerical simulations of the near field distributions confirmed the experimental results. As a proof-of-concept, we present a model biosensing experiment that exploits the dual-sensing capability, the size selectivity offered by the sensor geometry, and the possibility to separately biochemically modify the nanomenhirs and the nanocavities for the specific binding of lipid membrane structures to the nanomenhirs.
authors.affiliation: Department of Materials, Laboratory for Surface Science and Technology, Swiss Federal Institute of Technology (ETH Zürich) , CH-8093 Zürich, Switzerland.
authors.forename: Karthik
authors.initials: K
authors.lastname: Kumar
authors.forename: Andreas B
authors.initials: AB
authors.lastname: Dahlin
authors.forename: Takumi
authors.initials: T
authors.lastname: Sannomiya
authors.forename: Stefan
authors.initials: S
authors.lastname: Kaufmann
authors.forename: Lucio
authors.initials: L
authors.lastname: Isa
authors.forename: Erik
authors.initials: E
authors.lastname: Reimhult
mesh_terms: D015374:Biosensing Techniques; D006046:Gold / Q000737:chemistry; D008027:Light; D008055:Lipids / Q000737:chemistry*; D008566:Membranes / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D008055:Lipids; D006046:Gold