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Tip-Enhanced Raman Voltammetry: Coverage Dependence and Quantitative Modeling.
- Source :
-
Nano letters [Nano Lett] 2017 Jan 11; Vol. 17 (1), pp. 590-596. Date of Electronic Publication: 2016 Dec 13. - Publication Year :
- 2017
-
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, E <superscript>0'</superscript> , 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 E <superscript>0'</superscript> at each spatial location. Histograms of single-molecule E <superscript>0'</superscript> 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.
Details
- Language :
- English
- ISSN :
- 1530-6992
- Volume :
- 17
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Nano letters
- Publication Type :
- Academic Journal
- Accession number :
- 27936805
- Full Text :
- https://doi.org/10.1021/acs.nanolett.6b04868