Tunable multilayered nanospheres as probes for surface-enhanced Raman spectroscopy

Anil K. Kodali, Rohit Bhargava

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

Abstract

Giant electromagnetic field enhancements in the vicinity and within layered nanoparticles supporting surface plasmon resonances provide an excellent opportunity for ultra-sensitive Raman spectroscopy. Using metal nanoparticles, enhancement levels of very high sensitivity are achievable but quantitative control over them has traditionally been poor. We propose here multilayered nanospheres with alternating metal-dielectric layers as optimal and easily tailored probes for enhanced Raman scattering, terming these constructs nano-LAMPs (nano-Layered Metal Particles). A theoretical framework based on electromagnetic scattering calculations is used to describe the influence of parameters of the probes, viz. size, composition and spacing of metal and properties of dielectric layers. A recursive formulation of analytical Mie solution is used to evaluate scattering, and the theoretical tunability of electric field enhancement within the spheres is demonstrated as a function of design parameters. An optimization procedure is devised to obtain optimal configurations under fabrication constraints. While demonstrating significant surface enhancement effects, the optical tunability of nano-LAMPs is shown to provide an ability to design probes for multiple excitation frequencies.

Original languageEnglish (US)
Title of host publicationPlasmonics
Subtitle of host publicationMetallic Nanostructures and Their Optical Properties VI
DOIs
StatePublished - Nov 24 2008
EventPlasmonics: Metallic Nanostructures and Their Optical Properties VI - San Diego, CA, United States
Duration: Aug 10 2008Aug 14 2008

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume7032
ISSN (Print)0277-786X

Other

OtherPlasmonics: Metallic Nanostructures and Their Optical Properties VI
CountryUnited States
CitySan Diego, CA
Period8/10/088/14/08

Keywords

  • Electromagnetic field enhancement
  • Mie theory
  • Multilayered particles
  • Nanoparticles
  • Nanoprobes
  • Optical tunability
  • Raman hot-spots
  • Surface enhanced Raman spectroscopy
  • Surface plasmon resonance

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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  • Cite this

    Kodali, A. K., & Bhargava, R. (2008). Tunable multilayered nanospheres as probes for surface-enhanced Raman spectroscopy. In Plasmonics: Metallic Nanostructures and Their Optical Properties VI [70320V] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 7032). https://doi.org/10.1117/12.798168