Abstract
We present a dynamical effective medium theory (EMT) of the dielectric properties of nanoparticle aggregates formed from DNA-linked gold nanoparticles. Experimental measurements show that such aggregates have reduced UV extinction and plasmon bands that are considerably red-shifted and broadened relative to the plasmon absorption feature observed in spectra of dispersed colloid. The EMT, which can be used to reproduce the observed spectral changes, is tested by comparing aggregate spectra calculated using the EMT dielectric function with spectra from explicit coupled particle calculations, and good agreement is found. The EMT dielectric function is used as well in discrete dipole calculations to calculate extinction spectra for a variety of aggregate shapes not amenable to analytic solution, and the sensitivity of the spectra to aggregate shape is examined. We find that the spectra are only weakly sensitive to aggregate shape, and conclude that, when calculating extinction of the DNA-linked aggregates fo r comparison with experiment, spherical shapes can be assumed.
| Original language | English |
|---|---|
| Title of host publication | Materials Research Society Symposium - Proceedings |
| Editors | L.A. Lyon, S.J. Stranick, C.D. Keating, P.C. Searson |
| Volume | 635 |
| Publication status | Published - 2001 |
| Event | Anisotropic Nanoparticles-Synthesis, Characterization and Applications - Boston, MA, United States Duration: Nov 27 2000 → Nov 29 2000 |
Other
| Other | Anisotropic Nanoparticles-Synthesis, Characterization and Applications |
|---|---|
| Country | United States |
| City | Boston, MA |
| Period | 11/27/00 → 11/29/00 |
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ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
Cite this
Effective medium theory of DNA-linked gold nanoparticle aggregates : Effect of aggregate shape. / Lazarides, A. A.; Kelly, K. L.; Schatz, George C.
Materials Research Society Symposium - Proceedings. ed. / L.A. Lyon; S.J. Stranick; C.D. Keating; P.C. Searson. Vol. 635 2001.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Effective medium theory of DNA-linked gold nanoparticle aggregates
T2 - Effect of aggregate shape
AU - Lazarides, A. A.
AU - Kelly, K. L.
AU - Schatz, George C
PY - 2001
Y1 - 2001
N2 - We present a dynamical effective medium theory (EMT) of the dielectric properties of nanoparticle aggregates formed from DNA-linked gold nanoparticles. Experimental measurements show that such aggregates have reduced UV extinction and plasmon bands that are considerably red-shifted and broadened relative to the plasmon absorption feature observed in spectra of dispersed colloid. The EMT, which can be used to reproduce the observed spectral changes, is tested by comparing aggregate spectra calculated using the EMT dielectric function with spectra from explicit coupled particle calculations, and good agreement is found. The EMT dielectric function is used as well in discrete dipole calculations to calculate extinction spectra for a variety of aggregate shapes not amenable to analytic solution, and the sensitivity of the spectra to aggregate shape is examined. We find that the spectra are only weakly sensitive to aggregate shape, and conclude that, when calculating extinction of the DNA-linked aggregates fo r comparison with experiment, spherical shapes can be assumed.
AB - We present a dynamical effective medium theory (EMT) of the dielectric properties of nanoparticle aggregates formed from DNA-linked gold nanoparticles. Experimental measurements show that such aggregates have reduced UV extinction and plasmon bands that are considerably red-shifted and broadened relative to the plasmon absorption feature observed in spectra of dispersed colloid. The EMT, which can be used to reproduce the observed spectral changes, is tested by comparing aggregate spectra calculated using the EMT dielectric function with spectra from explicit coupled particle calculations, and good agreement is found. The EMT dielectric function is used as well in discrete dipole calculations to calculate extinction spectra for a variety of aggregate shapes not amenable to analytic solution, and the sensitivity of the spectra to aggregate shape is examined. We find that the spectra are only weakly sensitive to aggregate shape, and conclude that, when calculating extinction of the DNA-linked aggregates fo r comparison with experiment, spherical shapes can be assumed.
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M3 - Conference contribution
VL - 635
BT - Materials Research Society Symposium - Proceedings
A2 - Lyon, L.A.
A2 - Stranick, S.J.
A2 - Keating, C.D.
A2 - Searson, P.C.
ER -