[22p-A106-1~15] 12.6 Nanobiotechnology

[22p-A106-9] Analysis of Ca²⁺ Ion Diffusion Behavior in the Water Layer at the Lipid Bilayer/Substrate Interface

〇Hiroto Yoshimizu¹, Azusa Oshima², Masumi Yamaguchi², Akira Heya¹, Koji Sumitomo¹ (1.Univ. of Hyogo, 2.NTT Basic Res. Labs., BMC)

Keywords:diffusion coefficient, FRAP, surface charge

The diffusion coefficient of ions in the water layer between the lipid bilayer and the substrate was investigated. The effect of interaction with the substrate was examined by comparing it with the lateral diffusion of lipid molecules in the lipid bilayer. Coating with poly (L-ornithine), which gives a cationic surface potential, significantly reduced the diffusion coefficient of Ca²⁺ ions. Fluorescence recovery after photobleaching (FRAP) revealed that the diffusion coefficient of lipid molecules in the lipid bilayer was also reduced by the surface charge of the substrate. We discuss the behavior of the lipid bilayer and the characteristics of the device affected by the surface charge and the accompanying changes in interaction.