Effective medium theory of DNA-linked gold nanoparticle aggregates: Effect of aggregate shape

A. A. Lazarides, K. L. Kelly, George C Schatz

Research output: Chapter in Book/Report/Conference proceedingConference contribution

7 Citations (Scopus)

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 languageEnglish
Title of host publicationMaterials Research Society Symposium - Proceedings
EditorsL.A. Lyon, S.J. Stranick, C.D. Keating, P.C. Searson
Volume635
Publication statusPublished - 2001
EventAnisotropic Nanoparticles-Synthesis, Characterization and Applications - Boston, MA, United States
Duration: Nov 27 2000Nov 29 2000

Other

OtherAnisotropic Nanoparticles-Synthesis, Characterization and Applications
CountryUnited States
CityBoston, MA
Period11/27/0011/29/00

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Lazarides, A. A., Kelly, K. L., & Schatz, G. C. (2001). Effective medium theory of DNA-linked gold nanoparticle aggregates: Effect of aggregate shape. In L. A. Lyon, S. J. Stranick, C. D. Keating, & P. C. Searson (Eds.), Materials Research Society Symposium - Proceedings (Vol. 635)