Decoding of Carbohydrates With Monosaccharide-Level Resolution Using Tip-Enhanced Raman Scattering

Area of Science:

• Analytical Chemistry
• Biochemistry
• Spectroscopy

Background:

• Oligosaccharide analysis is crucial for understanding biological processes.
• Existing methods often lack sensitivity, specificity, or require labeling.

Purpose of the Study:

• To develop a high-sensitivity, label-free method for oligosaccharide analysis and synthesis monitoring.
• To leverage tip-enhanced Raman spectroscopy (TERS) with nanopillar trapping for enhanced glycan detection.

Main Methods:

• Integration of TERS with nanopillar-assisted glycan trapping.
• Utilizing mechanical confinement to generate plasmonic hot spots for signal amplification.
• Employing an azido tag for internal signal normalization.

Main Results:

• Achieved high sensitivity and reproducibility in vibrational spectra of oligosaccharides.
• Resolved subtle structural differences, including glycosidic linkage types (β(1→3) vs. β(1→4)).
• Enabled semi-quantitative estimation of oligosaccharide chain length and real-time monitoring of enzymatic glycosylation, such as fucosylation.

Conclusions:

• The developed TERS platform offers a powerful tool for label-free glycan sequence analysis.
• Demonstrated capability for dynamic monitoring of carbohydrate synthesis with high molecular specificity.
• Establishes TERS as a valuable technique for detailed analysis of complex carbohydrates.