title: Plasmonic DNA-origami nanoantennas for surface-enhanced Raman spectroscopy.
abstract: We report that plasmonic nanoantennas made by DNA origami can be used as reliable and efficient probes for surface-enhanced Raman spectroscopy (SERS). The nanoantenna is built up by two gold nanoparticles that are linked together by a three-layered DNA origami block at a separation distance of 6 nm in order to achieve plasmonic coupling and the formation of a plasmonic "hot spot". The plasmonic properties of the hybrid structure are optically characterized by dark-field imaging and polarization-dependent spectroscopy. SERS measurements on molecules that are embedded in the DNA origami that bridges the nanoantenna gap were performed in order to demonstrate the excellent performance of these structures for enhancing spectroscopic signals. A strong enhancement of the Raman signal was recorded from measurements on single hot spots compared to measurements in bulk. Finally, we show that the laser polarization with respect to the dimer orientation has a strong impact on the SERS performance.
authors.affiliation: Photonics and Optoelectronics Group, Department of Physics and Center for NanoScience (CeNS), LMU München , Amalienstrasse 54, Munich, 80799, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Kühler
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Roller
authors.forename: Robert
authors.initials: R
authors.lastname: Schreiber
authors.forename: Tim
authors.initials: T
authors.lastname: Liedl
authors.forename: Theobald
authors.initials: T
authors.lastname: Lohmüller
authors.forename: Jochen
authors.initials: J
authors.lastname: Feldmann
mesh_terms: D004247:DNA / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D007834:Lasers; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology; D011108:Polymers / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D011108:Polymers; D006046:Gold; D004247:DNA