title: Three dimensional sensitivity characterization of plasmonic nanorods for refractometric biosensors.
abstract: An experimental three dimensional characterization of the local refractive index sensitivity of plasmonic gold nanorods is performed by controlled apposition of lithographic nanostructures. We show up to seven times higher sensitivity values to local changes in the refractive index at the particle tip than center. In addition, successive deposition of defined nm-thin dielectric layers on nanorods covered with stripe masks allows us to study the sensitivity decrease normal to the particle surface separately for different particle sites. Clear trends to a stronger sensitivity decay at sites of higher local sensitivity are demonstrated experimentally and theoretically. Our sensitivity characterization provides an important tool to find the most suitable particle type and particle site for specific bio-sensing applications.
authors.affiliation: Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria. verena.leitg@gmail.com.
authors.forename: V
authors.initials: V
authors.lastname: Leitgeb
authors.affiliation: Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria. verena.leitg@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Trügler
authors.affiliation: JOANNEUM RESEARCH Forschungsgesellschaft mbH, MATERIALS-Institut für Oberflächentechnologien und Photonik, Leonhardstraße 59, 8010 Graz, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Köstler
authors.affiliation: Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria. verena.leitg@gmail.com.
authors.forename: M K
authors.initials: MK
authors.lastname: Krug
authors.affiliation: Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria. verena.leitg@gmail.com.
authors.forename: U
authors.initials: U
authors.lastname: Hohenester
authors.affiliation: Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria. verena.leitg@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Hohenau
authors.affiliation: Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria. verena.leitg@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Leitner
authors.affiliation: Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria. verena.leitg@gmail.com.
authors.forename: J R
authors.initials: JR
authors.lastname: Krenn
mesh_terms: D015374:Biosensing Techniques; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D043942:Nanotubes / Q000737:chemistry*; D019904:Polymethyl Methacrylate / Q000737:chemistry; D058525:Quartz Crystal Microbalance Techniques; D012822:Silicon Dioxide / Q000737:chemistry; D020349:Surface Plasmon Resonance
chemical_list: D006046:Gold; D012822:Silicon Dioxide; D019904:Polymethyl Methacrylate