Substrate effect on refractive index dependence of plasmon resonance for individual silver nanoparticles observed using darkfield microspectroscopy.

Journal Article (Journal Article)

We use optical darkfield micro-spectroscopy to characterize the plasmon resonance of individual silver nanoparticles in the presence of a substrate. The optical system permits multiple individual nanoparticles to be identified visually for simultaneous spectroscopic study. For silver particles bound to a silanated glass substrate, we observe changes in the Plasmon resonance due to induced variations in the local refractive index. The shifts in the plasmon resonance are investigated using a simple analytical theory in which the contributions from the substrate and environment are weighted with distance from the nanoparticle. The theory is compared with experimental results to determine a weighting factor which facilitates modeling of environmental refractive index changes using standard Mie code. Use of the optical system for characterizing nanoparticles attached to substrates for biosensing applications is discussed.

Full Text

Duke Authors

Cited Authors

  • Curry, A; Nusz, G; Chilkoti, A; Wax, A

Published Date

  • April 2005

Published In

Volume / Issue

  • 13 / 7

Start / End Page

  • 2668 - 2677

PubMed ID

  • 19495158

Electronic International Standard Serial Number (EISSN)

  • 1094-4087

International Standard Serial Number (ISSN)

  • 1094-4087

Digital Object Identifier (DOI)

  • 10.1364/opex.13.002668


  • eng