Power-Dependent Dual Analyte Tip-Enhanced Raman Spectral Imaging

O’Callahan, Brian T.; Bhattarai, Ashish; Schultz, Zachary D.; El-Khoury, Patrick Z.

doi:10.1021/acs.jpcc.0c05396

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Power-Dependent Dual Analyte Tip-Enhanced Raman Spectral Imaging

O’Callahan, Brian T.·Bhattarai, Ashish·Schultz, Zachary D.·El-Khoury, Patrick Z.

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Abstract

In this work, we explore the information content in tip-enhanced Raman (TER) spectral images of gold nanoplates coated with two distinct molecular reporters: 4-thiobenzonitrile (TBN) and 4-nitrothiophenol (NTP). Using our dual analyte approach, we rigorously demonstrate pixel-limited spatial resolution in Raman nano-images that are otherwise dominated by local optical fields that vary more gently in space. Reproducibility is ensured through power dependent TERS mapping. Power-dependent imaging also (i) directly illustrates that TBN is more robust than NTP at higher laser powers, and (ii) reveals an increase in population of the Stark-tuned nitrile resonances of TBN molecules with increasing incident laser power.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY Gold, plasmonics Raman spectroscopy lasers power

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O’Callahan, Brian T., Bhattarai, Ashish, Schultz, Zachary D., El-Khoury, Patrick Z.. 2020-06-18. Power-Dependent Dual Analyte Tip-Enhanced Raman Spectral Imaging. https://doi.org/10.1021/acs.jpcc.0c05396

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