SERS analysis of cancer cell-derived exosome phenotypes using a rare-earth ion coordination-dominated exosome capture...

Exosomes are important liquid biopsy markers for non-invasive cancer diagnosis, making efficient exosome isolation and precise detection particularly crucial. This study proposes an exosome capture strategy that leverages the coordination effect between rare-earth ions and negatively charged phosphate groups on the exosomal membrane surface, and combines it with surface-enhanced Raman spectroscopy (SERS) to develop an integrated capture-detection platform for exosome phenotyping. A rare-earth decorated magnetic bead composite nanomaterial (MB@RE) was constructed to enable rapid enrichment and magnetic separation of exosomes from cell culture supernatants, while three types of SERS immuno-probes composed of silver nanoparticles (AgNPs), specific antibodies, and Raman reporter molecules were prepared for the simultaneous multiplex detection of three exosomal surface proteins, CD63, EpCAM, and VEGF, derived from the MCF-7, SK-BR-3, and MCF-10A cell lines. This study presents a highly efficient approach for exosome capture that is feasible for in situ multiplex phenotypic analysis of exosomes.