Nanoscale chemical imaging using tip-enhanced Raman spectroscopy.

Area of Science:

• Nanoscale Chemical Imaging
• Spectroscopy
• Materials Science

Background:

• Confocal and surface-enhanced Raman spectroscopy (SERS) offer molecular characterization but are limited by diffraction.
• Tip-Enhanced Raman Spectroscopy (TERS) provides nanoscale chemical information, overcoming diffraction limitations.
• Atomic force microscopy (AFM)-based TERS is versatile but faces challenges with probe stability and yield.

Purpose of the Study:

• To detail a protocol for reliable nanoscale chemical imaging using transmission-mode AFM-TERS.
• To enable researchers to overcome experimental challenges in TERS probe preparation and system alignment.
• To facilitate the application of TERS to a diverse range of biological and non-biological samples.

Main Methods:

• Preparation of plasmonically active TERS probes.
• Alignment procedures for the TERS system.
• Experimental protocols for nanoscale imaging and data processing in TERS.

Main Results:

• Demonstrated reliable TERS imaging on various samples including polymer films, SAMs, graphene, and biological samples.
• Procedures are applicable in both air and liquid environments.
• TERS probes can be prepared in approximately 2-3 hours, with experiments taking 3-5 hours.

Conclusions:

• This protocol enables robust and versatile nanoscale chemical imaging using AFM-TERS.
• It addresses key experimental challenges, promoting wider adoption of TERS.
• The method is suitable for a broad spectrum of scientific investigations.