1 research outputs found
Gap-Dependent Coupling of Ag–Au Nanoparticle Heterodimers Using DNA Origami-Based Self-Assembly
We
fabricate heterocomponent dimers built from a single 40 nm gold
and a single 40 nm silver nanoparticle separated by sub-5 nm gaps.
Successful assembly mediated by a specialized DNA origami platform
is verified by scanning electron microscopy and energy-dispersive
X-ray characterization. Dark-field optical scattering on individual
dimers is consistent with computational simulations. Direct plasmonic
coupling between each nanoparticle is observed in both experiment
and theory only for these small gap sizes, as it requires the silver
dipolar mode energy to drop below the energy of the gold interband
transitions. A new interparticle-spacing-dependent coupling model
for heterodimers is thus required. Such Janus-like nanoparticle constructs
available from DNA-mediated assembly provide an effective tool for
controlling symmetry breaking in collective plasmon modes