Tip-Enhanced Raman Excitation Spectroscopy (TERES): Direct Spectral Characterization of the Gap-Mode Plasmon

Muwen Yang, Michael S. Mattei, Charles R. Cherqui, Xu Chen, Richard P. Van Duyne, George C. Schatz

Research output: Contribution to journalArticle

Abstract

The plasmonic properties of tip-substrate composite systems are of vital importance to near-field optical spectroscopy, in particular tip-enhanced Raman spectroscopy (TERS), which enables operando studies of nanoscale chemistry at a single molecule level. The nanocavities formed in the tip-substrate junction also offer a highly tunable platform for studying field-matter interactions at the nanoscale. While the coupled nanoparticle dimer model offers a correct qualitative description of gap-mode plasmon effects, it ignores the full spectrum of multipolar tip plasmon modes and their interaction with surface plasmon polariton (SPP) excitation in the substrate. Herein, we perform the first tip-enhanced Raman excitation spectroscopy (TERES) experiment and use the results, both in ambient and aqueous media, in combination with electrodynamics simulations, to explore the plasmonic response of a Au tip-Au substrate composite system. The gap-mode plasmon features a wide spectral window corresponding to a host of tip plasmon modes interacting with the plasmonic substrate. Simulations of the electric field confinement demonstrate that optimal spatial resolution is achieved when a hybrid plasmon mode that combines a multipolar tip plasmon and a substrate SPP is excited. Nevertheless, a wide spectral window over 1000 nm is available for exciting the tip plasmon with high spatial resolution, which enables the simultaneous resonant detection of different molecular species. This window is robust as a function of tip-substrate distance and tip radius of curvature, indicating that many choices of tips will work, but it is restricted to wavelengths longer than ∼600 nm for the Au tip-Au substrate combination. Other combinations, such as Ag tip-Ag substrate, can access wavelengths as low as 350 nm.

Original languageEnglish
Pages (from-to)7309-7316
Number of pages8
JournalNano letters
Volume19
Issue number10
DOIs
Publication statusPublished - Oct 9 2019

Fingerprint

Spectroscopy
Substrates
spectroscopy
excitation
Large scale systems
Wavelength
polaritons
Electrodynamics
spatial resolution
Dimers
Raman spectroscopy
composite materials
Electric fields
Nanoparticles
wavelengths
electrodynamics
Molecules
near fields
platforms
simulation

Keywords

  • gap-mode plasmon
  • plasmonic nanocavity
  • tip-enhanced Raman excitation spectroscopy (TERES)

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Cite this

Tip-Enhanced Raman Excitation Spectroscopy (TERES) : Direct Spectral Characterization of the Gap-Mode Plasmon. / Yang, Muwen; Mattei, Michael S.; Cherqui, Charles R.; Chen, Xu; Van Duyne, Richard P.; Schatz, George C.

In: Nano letters, Vol. 19, No. 10, 09.10.2019, p. 7309-7316.

Research output: Contribution to journalArticle

Yang, Muwen ; Mattei, Michael S. ; Cherqui, Charles R. ; Chen, Xu ; Van Duyne, Richard P. ; Schatz, George C. / Tip-Enhanced Raman Excitation Spectroscopy (TERES) : Direct Spectral Characterization of the Gap-Mode Plasmon. In: Nano letters. 2019 ; Vol. 19, No. 10. pp. 7309-7316.
@article{e569a305f45944c9bcbfbfee0a9393fa,
title = "Tip-Enhanced Raman Excitation Spectroscopy (TERES): Direct Spectral Characterization of the Gap-Mode Plasmon",
abstract = "The plasmonic properties of tip-substrate composite systems are of vital importance to near-field optical spectroscopy, in particular tip-enhanced Raman spectroscopy (TERS), which enables operando studies of nanoscale chemistry at a single molecule level. The nanocavities formed in the tip-substrate junction also offer a highly tunable platform for studying field-matter interactions at the nanoscale. While the coupled nanoparticle dimer model offers a correct qualitative description of gap-mode plasmon effects, it ignores the full spectrum of multipolar tip plasmon modes and their interaction with surface plasmon polariton (SPP) excitation in the substrate. Herein, we perform the first tip-enhanced Raman excitation spectroscopy (TERES) experiment and use the results, both in ambient and aqueous media, in combination with electrodynamics simulations, to explore the plasmonic response of a Au tip-Au substrate composite system. The gap-mode plasmon features a wide spectral window corresponding to a host of tip plasmon modes interacting with the plasmonic substrate. Simulations of the electric field confinement demonstrate that optimal spatial resolution is achieved when a hybrid plasmon mode that combines a multipolar tip plasmon and a substrate SPP is excited. Nevertheless, a wide spectral window over 1000 nm is available for exciting the tip plasmon with high spatial resolution, which enables the simultaneous resonant detection of different molecular species. This window is robust as a function of tip-substrate distance and tip radius of curvature, indicating that many choices of tips will work, but it is restricted to wavelengths longer than ∼600 nm for the Au tip-Au substrate combination. Other combinations, such as Ag tip-Ag substrate, can access wavelengths as low as 350 nm.",
keywords = "gap-mode plasmon, plasmonic nanocavity, tip-enhanced Raman excitation spectroscopy (TERES)",
author = "Muwen Yang and Mattei, {Michael S.} and Cherqui, {Charles R.} and Xu Chen and {Van Duyne}, {Richard P.} and Schatz, {George C.}",
year = "2019",
month = "10",
day = "9",
doi = "10.1021/acs.nanolett.9b02925",
language = "English",
volume = "19",
pages = "7309--7316",
journal = "Nano Letters",
issn = "1530-6984",
publisher = "American Chemical Society",
number = "10",

}

TY - JOUR

T1 - Tip-Enhanced Raman Excitation Spectroscopy (TERES)

T2 - Direct Spectral Characterization of the Gap-Mode Plasmon

AU - Yang, Muwen

AU - Mattei, Michael S.

AU - Cherqui, Charles R.

AU - Chen, Xu

AU - Van Duyne, Richard P.

AU - Schatz, George C.

PY - 2019/10/9

Y1 - 2019/10/9

N2 - The plasmonic properties of tip-substrate composite systems are of vital importance to near-field optical spectroscopy, in particular tip-enhanced Raman spectroscopy (TERS), which enables operando studies of nanoscale chemistry at a single molecule level. The nanocavities formed in the tip-substrate junction also offer a highly tunable platform for studying field-matter interactions at the nanoscale. While the coupled nanoparticle dimer model offers a correct qualitative description of gap-mode plasmon effects, it ignores the full spectrum of multipolar tip plasmon modes and their interaction with surface plasmon polariton (SPP) excitation in the substrate. Herein, we perform the first tip-enhanced Raman excitation spectroscopy (TERES) experiment and use the results, both in ambient and aqueous media, in combination with electrodynamics simulations, to explore the plasmonic response of a Au tip-Au substrate composite system. The gap-mode plasmon features a wide spectral window corresponding to a host of tip plasmon modes interacting with the plasmonic substrate. Simulations of the electric field confinement demonstrate that optimal spatial resolution is achieved when a hybrid plasmon mode that combines a multipolar tip plasmon and a substrate SPP is excited. Nevertheless, a wide spectral window over 1000 nm is available for exciting the tip plasmon with high spatial resolution, which enables the simultaneous resonant detection of different molecular species. This window is robust as a function of tip-substrate distance and tip radius of curvature, indicating that many choices of tips will work, but it is restricted to wavelengths longer than ∼600 nm for the Au tip-Au substrate combination. Other combinations, such as Ag tip-Ag substrate, can access wavelengths as low as 350 nm.

AB - The plasmonic properties of tip-substrate composite systems are of vital importance to near-field optical spectroscopy, in particular tip-enhanced Raman spectroscopy (TERS), which enables operando studies of nanoscale chemistry at a single molecule level. The nanocavities formed in the tip-substrate junction also offer a highly tunable platform for studying field-matter interactions at the nanoscale. While the coupled nanoparticle dimer model offers a correct qualitative description of gap-mode plasmon effects, it ignores the full spectrum of multipolar tip plasmon modes and their interaction with surface plasmon polariton (SPP) excitation in the substrate. Herein, we perform the first tip-enhanced Raman excitation spectroscopy (TERES) experiment and use the results, both in ambient and aqueous media, in combination with electrodynamics simulations, to explore the plasmonic response of a Au tip-Au substrate composite system. The gap-mode plasmon features a wide spectral window corresponding to a host of tip plasmon modes interacting with the plasmonic substrate. Simulations of the electric field confinement demonstrate that optimal spatial resolution is achieved when a hybrid plasmon mode that combines a multipolar tip plasmon and a substrate SPP is excited. Nevertheless, a wide spectral window over 1000 nm is available for exciting the tip plasmon with high spatial resolution, which enables the simultaneous resonant detection of different molecular species. This window is robust as a function of tip-substrate distance and tip radius of curvature, indicating that many choices of tips will work, but it is restricted to wavelengths longer than ∼600 nm for the Au tip-Au substrate combination. Other combinations, such as Ag tip-Ag substrate, can access wavelengths as low as 350 nm.

KW - gap-mode plasmon

KW - plasmonic nanocavity

KW - tip-enhanced Raman excitation spectroscopy (TERES)

UR - http://www.scopus.com/inward/record.url?scp=85072969696&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85072969696&partnerID=8YFLogxK

U2 - 10.1021/acs.nanolett.9b02925

DO - 10.1021/acs.nanolett.9b02925

M3 - Article

C2 - 31518135

AN - SCOPUS:85072969696

VL - 19

SP - 7309

EP - 7316

JO - Nano Letters

JF - Nano Letters

SN - 1530-6984

IS - 10

ER -