Mastering high resolution tip-enhanced Raman spectroscopy: towards a shift of perception

Area of Science:

• Spectroscopy
• Nanotechnology
• Materials Science

Background:

• Recent tip-enhanced Raman spectroscopy (TERS) experiments demonstrate unprecedented spatial resolutions, reaching the sub-nanometer scale.
• Theoretical investigations support these high resolutions, contrasting with the long-held belief of tip-limited resolution (tens of nanometers).

Purpose of the Study:

• To address the discrepancy between experimental high-resolution TERS results and established theoretical limits.
• To critically re-evaluate the factors limiting resolution in TERS from both theoretical and experimental perspectives.
• To provide insights for advancing TERS capabilities in nanoscale research.

Main Methods:

• Review of recent experimental TERS data indicating sub-nanometer spatial resolution.
• Analysis of theoretical models and plasmonic principles relevant to TERS resolution.
• Discussion of practical factors influencing TERS performance and reproducibility.

Main Results:

• Experimental evidence strongly suggests achievable resolutions far beyond the previously accepted tens of nanometers.
• Theoretical frameworks, particularly those based on plasmonics, support the possibility of sub-nanometer resolution in TERS.
• A significant divergence exists between reported TERS resolutions and the intrinsic capabilities suggested by recent findings.

Conclusions:

• A deeper understanding of accessible lateral resolution in TERS is essential for the technique's advancement.
• Addressing the gap between theoretical potential and practical application will enhance TERS for studying organic, inorganic, and biological nanoscale features.
• Improved comprehension of TERS resolution limits will boost reproducibility and accuracy in routine studies.