Near-field Optical Image of Lipid Bilayers in Liquid Phase

Jia Ru Yu^1,2*, Wei Ssu Liao², Ing-Shouh Hwang³, Chi Chen¹

¹Research Center of Applied Science, Academia Sinica, Taipei City, Taiwan
²Chemistry, National Taiwan University, Taipei City, Taiwan
³Institute of Physics, Academia Sinica, Taipei City, Taiwan

* Presenter:Jia Ru Yu, email:puddingdes@gmail.com

a-SNOM is a potential tool for nanoscale optical imaging. For biological samples, we need to work in a liquid environment, and moreover, we need scanning harmless to the sample by the blunt a-SNOM tip. However, most of the commercial a-SNOM systems only work in the ambient and operational mode (contact mode and share force) is harmful to soft material. Therefore, we develop the tapping mode SNOM in the liquid phase. We designed and built the AFM-SNOM system capable of stable AFM operation corporate with the optical path in the liquid phase. By our homemade SNOM system, we obtain simultaneous topography and fluorescence mapping of dye-labeled lipids using small amplitude (<2 nm) tapping mode in the liquid phase. The fluorescence image shows that the distribution of dye is inhomogeneous in lipid bilayers. The dyes were pushed to the edge of lipid bilayers. In the future, we plan to study the dye-label lipid distribution in the different lipid phases and monitor the lipid-peptide reaction.

Keywords: a-SNOM, near-field optics, lipid bilayers