Classical vs quantum plasmons are operative in tapping vs contact mode tip-enhanced Raman scattering (TERS) and lead to distinct observables. Under otherwise identical experimental conditions, we illustrate the concept through tapping and contact mode TERS mapping of chemically functionalized silver nanocubes. Whereas molecular charging, chemical transformations, and optical rectification are prominent observables in contact mode TERS, the same effects are suppressed using tapping mode feedback. In effect, this work demonstrates that nanoscale physical and chemical processes can be accessed/suppressed on-demand in the TERS geometry. The advantages of tapping mode TERS are otherwise highlighted with the latter in mind.
Published: February 4, 2022
Citation
Wang C., B.T. O'Callahan, D. Kurouski, A.V. Krayev, Z. Schultz, and P.Z. El-Khoury. 2020.Suppressing Molecular Charging, Nanochemistry, and Optical Rectification in the Tip-Enhanced Raman Geometry.The Journal of Physical Chemistry Letters 11, no. 15:5890–5895.PNNL-SA-153064.doi:10.1021/acs.jpclett.0c01413