Feasibility study using surface-enhanced Raman spectroscopy for the quantitative detection of tyrosine and serine...

Area of Science:

• Analytical Chemistry
• Biochemistry
• Spectroscopy

Background:

• Peptide phosphorylation is a critical post-translational modification regulating numerous cellular processes.
• Accurate quantification of peptide phosphorylation is essential for understanding biological pathways and disease mechanisms.
• Existing techniques like HPLC can be time-consuming and may lack sensitivity for low-concentration analyses.

Purpose of the Study:

• To evaluate the feasibility of colloid-based surface-enhanced Raman scattering (SERS) for sensitive peptide phosphorylation detection.
• To establish SERS as a viable alternative to conventional methods for near-real-time phosphorylation analysis.
• To demonstrate the robustness of SERS in complex biological matrices.

Main Methods:

• Utilized drop-coating deposition Raman (DCDR) method for SERS measurements.
• Validated SERS spectra against normal Raman spectra for low-concentration detection.
• Employed Savistky-Golay second derivative (SGSD) for spectral pre-processing.
• Applied interval partial least squares (iPLS) for multivariate spectral classification to determine phosphorylation levels.

Main Results:

• SERS successfully detected peptide phosphorylation at serine and tyrosine residues with high sensitivity.
• Validated SERS spectra against normal Raman spectra, confirming accuracy at low concentrations.
• Demonstrated near-real-time measurement capabilities with short scanning and processing times.
• Showcased robustness against interference from complex proteins and other phosphorylated compounds.

Conclusions:

• Colloid-based SERS is a highly sensitive and rapid technique for detecting peptide phosphorylation.
• SERS offers a significant advantage over HPLC for near-real-time, sub-micromolar concentration measurements.
• The developed SERS method is robust and suitable for high-throughput screening assays.