Trapping and SERS identification of extracellular vesicles using nanohole arrays

Extracellular vesicles are nanoscale and microscale biological vesicles actively released by nearly all cell types within the body. These small vesicles have been shown to play important biological roles, including cell-to-cell communication, coagulation and signal transduction. They have also been shown to play oncogenic roles in cancer metastasis and progression. Extracellular vesicles are composed of an aqueous cytosolic core and a phospholipid membrane, and exhibit variability in their internal and external cargoes. Developing a better understanding of the structure and diversity of the components of extracellular vesicles may hold promise in uncovering the pathways involved in the formation and progression of various cancers and diseases. Current studies of extracellular vesicles focus on bulk analysis, whereas variability amongst individual extracellular vesicles has been minimally reported in literature. In this study, we propose the use of a surface-enhanced Raman spectroscopy platform in movement towards trapping extracellular vesicles secreted from a mesenchymal stem cell line followed by probing their individual spectral signatures. Here, we propose the use of plasmonic-well based structures as a means of isolating, trapping and controlling the position of biologically relevant vesicles on plasmonic platforms. Trapping and identification of extracellular vesicles occurs without use of labelling agents, allowing for characterization of the intrinsic molecular information of individual extracellular vesicles.