10.1021/ja300901e.s001
Mahmoud
A. Mahmoud
Mahmoud
A.
Mahmoud
Maysamreza Chamanzar
Maysamreza
Chamanzar
Ali Adibi
Ali
Adibi
Mostafa A. El-Sayed
Mostafa A.
El-Sayed
Effect of the Dielectric
Constant of the Surrounding
Medium and the Substrate on the Surface Plasmon Resonance Spectrum
and Sensitivity Factors of Highly Symmetric Systems: Silver Nanocubes
American Chemical Society
2012
nanoparticle
extinction surface plasmon resonance
Silver NanocubesSilver nanocubes
absorption
SPR
plasmon field
Surface Plasmon Resonance Spectrum
difference time domain
plasmon field intensity
dielectric
60 nm AgNC
FDTD
2012-04-11 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Effect_of_the_Dielectric_Constant_of_the_Surrounding_Medium_and_the_Substrate_on_the_Surface_Plasmon_Resonance_Spectrum_and_Sensitivity_Factors_of_Highly_Symmetric_Systems_Silver_Nanocubes/2531893
Silver nanocubes (AgNCs), 60 nm, have four extinction
surface plasmon
resonance (SPR) peaks. The finite difference time domain (FDTD) simulation
method is used to assign the absorption and scattering peaks and also
to calculate the plasmon field intensity for AgNCs. Because AgNCs
have a highly symmetric cubic shape, there is a uniform distribution
of the plasmon field around them, and they are thus sensitive to asymmetric
dielectric perturbations. When the dielectric medium around a nanoparticle
is changed anisotropically, either by placing the particle on a substrate
or by coating it asymmetrically with a solvent, the plasmon field
is distorted, and the plasmonic absorption and scattering spectra
could shift differently. For the 60 nm AgNC, we found that the scattering
resonance peak shifted more than the absorption peak. This changes
the extinction bandwidth of these overlapping absorption and scattering
bands, and consequently the figure of merit of the nanoparticle, as
a localized SPR sensor, no longer has a constant value.