Tip-Enhanced Raman Voltammetry: Coverage Dependence and Quantitative Modeling

Michael Mattei, Gyeongwon Kang, Guillaume Goubert, Dhabih V. Chulhai, George C. Schatz, Lasse Jensen, Richard P. Van Duyne

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

Electrochemical atomic force microscopy tip-enhanced Raman spectroscopy (EC-AFM-TERS) was employed for the first time to observe nanoscale spatial variations in the formal potential, E0′, of a surface-bound redox couple. TERS cyclic voltammograms (TERS CVs) of single Nile Blue (NB) molecules were acquired at different locations spaced 5-10 nm apart on an indium tin oxide (ITO) electrode. Analysis of TERS CVs at different coverages was used to verify the observation of single-molecule electrochemistry. The resulting TERS CVs were fit to the Laviron model for surface-bound electroactive species to quantitatively extract the formal potential E0′ at each spatial location. Histograms of single-molecule E0′ at each coverage indicate that the electrochemical behavior of the cationic oxidized species is less sensitive to local environment than the neutral reduced species. This information is not accessible using purely electrochemical methods or ensemble spectroelectrochemical measurements. We anticipate that quantitative modeling and measurement of site-specific electrochemistry with EC-AFM-TERS will have a profound impact on our understanding of the role of nanoscale electrode heterogeneity in applications such as electrocatalysis, biological electron transfer, and energy production and storage.

Original languageEnglish
Pages (from-to)590-596
Number of pages7
JournalNano letters
Volume17
Issue number1
DOIs
Publication statusPublished - Jan 11 2017

Keywords

  • Laviron model
  • Tip-enhanced Raman spectroscopy (TERS)
  • cyclic voltammetry
  • single-molecule electrochemistry

ASJC Scopus subject areas

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

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  • Cite this

    Mattei, M., Kang, G., Goubert, G., Chulhai, D. V., Schatz, G. C., Jensen, L., & Van Duyne, R. P. (2017). Tip-Enhanced Raman Voltammetry: Coverage Dependence and Quantitative Modeling. Nano letters, 17(1), 590-596. https://doi.org/10.1021/acs.nanolett.6b04868