Creating hot nanoparticle pairs for surface-enhanced Raman spectroscopy through optical manipulation.
We use optical tweezers to move single silver nanoparticles into near-field contact with immobilized particles, forming isolated surface-enhanced Raman spectroscopy (SERS) active Ag particle dimers. The surface-averaged SERS intensity increases by a factor approximately 20 upon dimerization. Electrodynamics calculations indicate that the final approach between the particles is due to "optical binding". The described methodology may facilitate controlled single molecule SERS analysis.
Svedberg
Fredrik
F
Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
Li
Zhipeng
Z
Xu
Hongxing
H
Käll
Mikael
M
D053768:Metal Nanoparticles; D052898:Optical Tweezers; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*
D012834:Silver