Low-concentration chemical sensing using surface-enhanced coherent anti-Stokes Raman spectroscopy

ORAL

Abstract

Measurements of surface enhanced coherent anti-Stokes Raman spectra (CARS) of cyclohexane are carried out. Random aggregates of gold nanoparticles for field enhancement were deposited on a glass substrate and were characterized using atomic force microscopy (AFM). Surface enhancement of the CARS signal by gold nanoparticles is observed. This technique can be used to detect low amounts of chemicals with a higher sensitivity compared to the conventional surface-enhanced Raman spectroscopy (SERS). The lowest detected concentration of cyclohexane in a thin film of methanol was 1{\%}. However, it was not possible to detect any signal from the same sample of cyclohexane without gold nanoparticles using conventional CARS technique. Therefore, surface enhancement is necessary to achieve higher spectroscopy sensitivity. Further studies of nanostructure-enhanced electrical fields are required to quantitatively understand the observed effects and will be performed in the future.

*We acknowledge the support of the Robert A. Welch Foundation (A-1261).

–

Authors

  • Xia Hua

    • Physics Department and Institute for Quantum Science and Engineering, Texas A\&M University, College Station, TX, 77843

  • Alexander Sinyukov

    • Physics Department and Institute for Quantum Science and Engineering, Texas A\&M University, College Station, TX, 77843

  • Andrew Traverso

    • Physics Department and Institute for Quantum Science and Engineering, Texas A\&M University, College Station, TX, 77843

  • Dmitri Veronine

    • Physics Department and Institute for Quantum Science and Engineering, Texas A\&M University, College Station, TX, 77843

  • Kai Wang

    • Texas A\&M University
    • Physics Department and Institute for Quantum Science and Engineering, Texas A\&M University, College Station, TX, 77843

  • Hui Xia

    • Physics Department and Institute for Quantum Science and Engineering, Texas A\&M University, College Station, TX, 77843

  • Wenlong Yang

    • Physics Department and Institute for Quantum Science and Engineering, Texas A\&M University, College Station, TX, 77843

  • Luqi Yuan

    • Physics Department and Institute for Quantum Science and Engineering, Texas A\&M University, College Station, TX, 77843

  • Alexei Sokolov

    • Physics Department and Institute for Quantum Science and Engineering, Texas A\&M University, College Station, TX, 77843

  • Marlan Scully

    • Physics Department and Institute for Quantum Science and Engineering, Texas A\&M University, College Station, TX, 77843
    • Texas A\&M University and Princeton University