Apertureless near-field Raman spectroscopy

Area of Science:

• Nanotechnology
• Spectroscopy
• Materials Science

Background:

• Raman spectroscopy provides valuable molecular information but often suffers from weak signals.
• Scanning probe microscopy offers high-resolution surface imaging and manipulation capabilities.

Purpose of the Study:

• To investigate the application of tip-enhanced Raman spectroscopy (TERS) for analyzing C60 molecules.
• To demonstrate the capability of a custom-built apertureless scanning near-field optical microscope (SNOM) for simultaneous topographic and spectral measurements.

Main Methods:

• Utilized a custom-built apertureless SNOM system.
• Employed a commercial atomic force microscope (AFM) tip coated with 100 nm of gold.
• Acquired tip-enhanced Raman spectra of C60 samples.

Main Results:

• Successfully obtained tip-enhanced Raman spectra of C60.
• Demonstrated the localized enhancement of the Raman signal by the gold-coated AFM tip.
• Achieved simultaneous acquisition of topographic and spectral data.

Conclusions:

• The developed TERS system effectively enhances Raman signals for molecular analysis.
• The gold-coated AFM tip plays a crucial role in the signal enhancement.
• This technique shows promise for high-resolution chemical imaging of materials like C60.