Laser ablation surface-enhanced Raman microspectroscopy.

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Materials Science

Background:

• Identifying trace organic compounds in complex samples is crucial for material science, heritage science, and forensics.
• Surface-enhanced Raman scattering (SERS) offers high sensitivity but requires robust methods for broad application.
• Existing SERS techniques often lack the necessary spatial resolution and sensitivity for challenging matrices.

Purpose of the Study:

• To develop a highly sensitive and widely applicable SERS approach for analyzing trace organic compounds.
• To overcome limitations in sensitivity and spatial resolution of current SERS methods.
• To demonstrate the utility of the new method on complex and historically significant samples.

Main Methods:

• Development of a novel SERS analysis method utilizing laser ablation in the presence of a tailored plasmonic substrate.
• Application of the method to analyze challenging compounds, including non-water-soluble pigments and ancient dyed leather.
• Characterization of sensitivity and spatial resolution achieved by the new technique.

Main Results:

• Achieved high sensitivity, as low as 120 amol (attomoles) with a 1:1 signal-to-noise ratio.
• Demonstrated a spatial resolution of 5 μm, a significant improvement over existing SERS approaches.
• Successfully analyzed complex samples, including materials from an ancient Egyptian chariot.

Conclusions:

• The developed laser ablation-based SERS method offers orders of magnitude improvement in sensitivity and spatial resolution.
• This approach greatly enhances the applicability of SERS for analyzing trace organic compounds in diverse and challenging matrices.
• The technique holds significant potential for advancing fields requiring high-resolution chemical analysis of complex materials.