Coral-like plasmonic probes for tip-enhanced Raman spectroscopy

Area of Science:

• Nanotechnology
• Spectroscopy
• Materials Science

Background:

• Tip-Enhanced Raman Spectroscopy (TERS) provides nanoscale chemical analysis.
• High-performance TERS probes are challenging to fabricate due to the required nanostructures.
• Metallic nanostructures at the probe apex are crucial for TERS sensitivity and resolution.

Purpose of the Study:

• To present a facile, rapid, and effective approach for preparing silver-based TERS probes.
• To develop TERS probes with enhanced plasmonic activity and tunable nanotexture.
• To offer a method for restoring oxidized TERS tips.

Main Methods:

• Fabrication of TERS probes using spinodal dewetting of silver-coated AFM probes.
• Application of RF plasma treatment to induce silver nanotexture formation.
• Tuning of nanotexture by adjusting silver film thickness and plasma exposure time.

Main Results:

• Obtained TERS probes feature a coral-like silver nanotexture with excellent plasmonic activity.
• TERS enhancement factor of 10^7 achieved.
• Spatial resolution down to 10 nm demonstrated.
• Tunable nanotexture by controlling fabrication parameters.

Conclusions:

• The developed method provides a reproducible way to fabricate high-performance Ag-based TERS probes.
• The tunable coral-like silver nanotexture enhances plasmonic activity for superior TERS performance.
• An effective tip restoration procedure extends the usability of Ag-based TERS probes.