Lipid Layer Formation on Particle Surfaces by Using DNA-Containing Recruiter Molecules*

Biofunctional interfaces containing DNA-conjugated molecules have been explored for various bioengineering applications. In this study, we prepare DNA-containing recruiter molecules and incorporate them onto DNA immobilized gold nanoparticles through DNA hybridization. Liposomes composed of different phospholipids are then applied to investigate supported lipid layer formation on these recruiter-containing surfaces. We find that the morphology and the amount of lipid layers formed are determined by both the liposome concentration and the type of recruiter molecule. When liposomes are applied in excess above a critical concentration, surface chemistry determines the lipid layers formed, leading to lipid multilayers on hydrophilic DNA recruiter containing surface and lipid monolayers on hydrophobic DNA-lipid recruiter containing surfaces. When the liposome concentration is below the critical value, then surface chemistry is overtaken by recruiter-lipid interactions, leading to the active lipid recruitment on particle surfaces. The total amount of the lipid layers formed is further modulated by the overall charge and the fluidity of the liposomes applied.