[13p-A407-1~16] 12.6 Nanobiotechnology

[13p-A407-16] Dual Color Fluorescence Imaging of a 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 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 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 was detected using two different detection antibodies with a Bull’s eye plasmonic chip, while it was difficult to be detected on the glass substrates. Plasmonic chip was prepared by UV-nanoimprint method and silver film coating. 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 or PE-CD81 antibody was bound to CD63 antibody. Full width at half maximum (FWHM) and fluorescence intensity were individually analyzed for bright spots. Bright spot with FWHM less than 570 nm, which is threshold value determined by measureing fluorescent beads with a 200 nm-diameter, was regarded as a single exosome. Single exosomes were sensitively counted with two deferent antibodies on the plasmonic chip.