nl5009635_si_001.pdf (513.52 kB)
Plasmonic DNA-Origami Nanoantennas for Surface-Enhanced Raman Spectroscopy
journal contribution
posted on 2014-05-14, 00:00 authored by Paul Kühler, Eva-Maria Roller, Robert Schreiber, Tim Liedl, Theobald Lohmüller, Jochen FeldmannWe
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.