Forming two-dimensional structure of DNA-functionalized Au nanoparticles via lipid diffusion in supported lipid bilayers

Abstract

Two-dimensional (2D) form of DNA-functionalized gold nanoparticles (DNA–AuNPs) has been studied. To confine the DNA–AuNPs in 2D space, we utilized the strong affinity between DNA molecules and supported lipid bilayers (SLBs). DNA–AuNPs adsorbed onto cationic SLB consisting of Dimethyl dioctadecyl ammonium bromide (DDAB) on mica substrate with high affinity. Owing to the high mobility of lipid molecules, 2D diffusion and transportation of DNA–AuNPs on the SLB was achieved. Using AFM imaging we confirmed a selective adsorption of DNA–AuNPs onto cationic lipid bilayer patches on mica surface, and then we confirmed a drastic formation change of DNA–AuNPs on the SLB with annealing. We observed that the DNA–AuNPs assembled into a densely-packed single-layered 2D superstructure through DNA hybridization.