Raman Detection of Collagen Biomarkers

Raman scattering, a process where photons interact with molecules altering their energy levels, underpins Raman spectroscopy, a potent analytical technique for detecting analytes via molecular vibrations. This method has been instrumental in analyzing native collagen, including type I and type IV collagens, as well as studying the effect of temperature on type I collagen conformation. Surface-enhanced Raman spectroscopy (SERS) represents a significant advancement in molecular analysis, overcoming the inherent limitations of weak Raman signals. Recent progress in bioanalysis has been driven by robust SERS tags, incorporating essential elements such as plasmonic nanoparticle cores, Raman reporters, protective coatings, and targeting molecules. Dual SERS probes, such as Ag@R1@PCTP (S-P) and Ag@R2@ICTP (S-I), serve as precise biosensors for detecting pathological type I collagen in connective tissues. Additionally, stable SERS/fluorescent dual-mode peptide probes (SF-I, SF-IV, and SF-D) enable accurate detection and profiling of type I, type IV, and denatured collagen, facilitating hepatic fibrosis staging. The advancements in Raman spectroscopy and SERS have revolutionized biomolecule analysis, offering promising avenues for further breakthroughs in clinical diagnostics.