[18p-E203-1~16] 12.6 Nanobiotechnology

[18p-E203-15] Fluorescence microscopy imaging of single exosome by plasmonic chip

〇Eri Fujimoto¹, Keiko Tawa¹ (1.Kwansei Gakuin Univ)

Keywords:plasmonic chip, single exosome, GC-SPR

Exosomes including micro-RNA and proteins are endoplasmic reticulum secreted from cells and the study of exosomes makes the prediction of disease likely to contract in the future possible. However, small exosomes with a diameter of around 100 nm are difficult to be in situ detected. Plasmonic chip can provide an enhanced electric field based on the grating-coupled surface plasmon resonance. In this study, fluorescently labeled single exosome was observed with a Bull’s eye plasmonic chip under upright fluorescence microscope, which is difficult to be detected on the glass substrates. Plasmonic chip was prepared by UV-nanoimprint method and silver film coating by RF-sputtering. Plasmonic chip surface was covered with polydopamine thin film for binding Protein G, and then, anti-CD63 antibody was immobilized to Protein G layer for capturing exosomes. An exosome labeled with APC-CD9 antibody was bound to CD63 antibody. Full width at half maximum (FWHM) and fluorescence intensity were individually analyzed for bright spots in the fluorescence image. The spots with FWHM close to diffraction limit (-600 nm) were considered as a single exosome