Lattice rayleigh anomaly associated enhancement of nh and ch stretching modes on gold metasurfaces for overtone detection

Daler R. Dadadzhanov, Tigran A. Vartanyan, Alina Karabchevsky

    Research output: Contribution to journalArticlepeer-review

    Abstract

    Molecular overtones stretching modes that occupy the near-infrared (NIR) are weak compared to the fundamental vibrations. Here we report on the enhancement of absorption by molecular vibrations overtones via electromagnetic field enhancement of plasmonic nanoparallelepipeds comprising a square lattice. We explore numerically, using finite element method (FEM), gold metasurfaces on a transparent dielectric substrate covered by weakly absorbing analyte supporting N-H and C-H overtone absorption bands around 1.5 µm and around 1.67 µm, respectively. We found that the absorption enhancement in N-H overtone transition can be increased up to the factor of 22.5 due to the combination of localized surface plasmon resonance in prolonged nanoparticles and lattice Rayleigh anomaly. Our approach may be extended for sensitive identification of other functional group overtone transitions in the near-infrared spectral range.

    Original languageEnglish
    Article number1265
    Pages (from-to)1-13
    Number of pages13
    JournalNanomaterials
    Volume10
    Issue number7
    DOIs
    StatePublished - 1 Jul 2020

    Keywords

    • Localized surface plasmon resonance
    • Metasurface
    • Overtone spectroscopy
    • Surface-enhanced near-infrared absorption

    All Science Journal Classification (ASJC) codes

    • General Chemical Engineering
    • General Materials Science

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