Intensified surface enhanced Raman signal of a graphene monolayer on a plasmonic substrate through the use of fluidic dielectrics

A. Mahigir, M. R. Gartia, T. W. Chang, Gang Logan Liu, G. Veronis

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

Abstract

It has been shown that surface enhanced Raman spectroscopy (SERS) has many promising applications in ultrasensitive detection of Raman signal of substances. However, optimizing the enhancement in SERS signal for different applications typically requires several levels of fabrication of active plasmonic SERS substrates. In this paper, we report the enhancement of SERS signal of a single layer of graphene located on a plasmonic nano-Lycurgus cup array after placing water droplets on it. The experimental data shows that addition of water droplets can enhance the SERS signal of the single layer of graphene about 10 times without requiring any modifications to the nano-Lycurgus cup array. Using fullwave electromagnetic simulations, we show that addition of water droplets enhances the local electric field at the graphene layer, resulting in stronger light-graphene interaction at the excitation pump laser wavelength. We also show that the addition of water droplets on the graphene layer enables us to modify the band diagram of the structure, in order to enhance the local density of optical states at the Raman emission wavelengths of the graphene layer. Numerical calculations of both the excitation field enhancement at the location of the graphene layer, and the emission enhancement due to enhanced local density of optical states, support the experimental results. Our results demonstrate an approach to boost the SERS signal of a target material by controlling the band diagram of the active nanostructured SERS substrate through the use of fluidic dielectrics. These results could find potential applications in biomedical and environmental technologies.

Original languageEnglish (US)
Title of host publicationPlasmonics in Biology and Medicine XIV
EditorsTuan Vo-Dinh, Joseph R. Lakowicz
PublisherSPIE
ISBN (Electronic)9781510606012
DOIs
StatePublished - Jan 1 2017
EventPlasmonics in Biology and Medicine XIV - San Francisco, United States
Duration: Jan 30 2017 → …

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume10080
ISSN (Print)1605-7422

Other

OtherPlasmonics in Biology and Medicine XIV
CountryUnited States
CitySan Francisco
Period1/30/17 → …

Keywords

  • Absorption
  • Graphene
  • Local density of optical states
  • Surface enhanced Raman spectroscopy

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Biomaterials
  • Radiology Nuclear Medicine and imaging

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  • Cite this

    Mahigir, A., Gartia, M. R., Chang, T. W., Liu, G. L., & Veronis, G. (2017). Intensified surface enhanced Raman signal of a graphene monolayer on a plasmonic substrate through the use of fluidic dielectrics. In T. Vo-Dinh, & J. R. Lakowicz (Eds.), Plasmonics in Biology and Medicine XIV [1008005] (Progress in Biomedical Optics and Imaging - Proceedings of SPIE; Vol. 10080). SPIE. https://doi.org/10.1117/12.2252614