[10p-Z12-1~21] 12.6 Nanobiotechnology

[10p-Z12-10] Dual Color Imaging of Single Exosome with Bull's eye Plasmonic Chip

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

Keywords:plasmonic chip, single exosome, GC-SPR

Exosomes 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 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, a single exosome captured with a sandwich immunoassay was observed on the plasmonic chip under fluorescence microscope. By dual color imaging using two types of detection antibodies, two kinds of membrane proteins included in exosome were simultaneously detected with a Bull’s eye chip composed of concentric circles. Chip surface was covered with polydopamine thin film for binding Protein G, and then, anti-CD63 antibody was immobilized. An exosome labeled with APC-CD9 antibody and PE-CD81 antibody was bound to CD63 antibody. According to the fluorescence image of fluorescent silica particles with 200 nm φ as large as an exosome, the threshold value was determined to be 570 nm in the full width at half maximum (FWHM) of a bright spot. Single exosomes were detection with two different proteins on the plasmonic chip.