Mapping Molecular Adsorption Configurations with <5 nm Spatial Resolution through Ambient Tip-Enhanced Raman Imaging

We interrogate para-mercaptobenzoic acid (MBA) molecules chemisorbed onto plasmonic silver nanocubes through tip-enhanced Raman (TER) spectral nanoimaging. Through a detailed examination of the spectra, aided by correlation analysis and density functional theory calculations, we find that MBA chemisorbs onto the plasmonic particles with at least two distinct configurations: S- and CO2- bound. High spatial resolution TER mapping allows us to distinguish between the distinct adsorption geometries with a pixel-limited (<5 nm) spatial resolution under ambient laboratory conditions.

Automated summary

The study reveals that para-mercaptobenzoic acid molecules chemisorbed onto plasmonic silver nanocubes exist in at least two distinct configurations: S- and CO2- bound. By using high spatial resolution TER mapping, the distinct adsorption geometries can be distinguished with a pixel-limited spatial resolution of less than 5 nm under ambient laboratory conditions.