title: Free-standing optical gold bowtie nanoantenna with variable gap size for enhanced Raman spectroscopy.
abstract: We describe plasmonic interactions in suspended gold bowtie nanoantenna leading to strong electromagnetic field (E) enhancements. Surface-enhanced Raman scattering (SERS) was used to demonstrate the performance of the nanoantenna. In addition to the well-known gap size dependence, up to 2 orders of magnitude additional enhancement is observed with elevated bowties. The overall behavior is described by a SERS enhancement factor exceeding 10(11) along with an anomalously weak power law dependence of E on the gap size in a range from 8 to 50 nm that is attributed to a plasmonic nanocavity effect occurring when the plasmonic interactions enter a strongly coupled regime.
authors.affiliation: Environmental Sciences.
authors.forename: Nahla A
authors.initials: NA
authors.lastname: Hatab
authors.forename: Chun-Hway
authors.initials: CH
authors.lastname: Hsueh
authors.forename: Abigail L
authors.initials: AL
authors.lastname: Gaddis
authors.forename: Scott T
authors.initials: ST
authors.lastname: Retterer
authors.forename: Jia-Han
authors.initials: JH
authors.lastname: Li
authors.forename: Gyula
authors.initials: G
authors.lastname: Eres
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Zhang
authors.forename: Baohua
authors.initials: B
authors.lastname: Gu