Abstract
Abstract Small-Angle X-ray scattering (SAXS) was used to investigate the dispersion of thiolated gold nanoparticles (Au-16C and Au-8C NPs) with DPPC, DiC7PC, and their combination of molar ratio 1:1. It was found that adding small amounts of phospholipids to disperse the synthesized thiolated small Au NPs in water phase would induce the formation of small thiolated-Au NP clusters that presumably are wrapped by a monolayer of phospholipids on the surface of the cluster, resembling the swollen micellar structure. However, when larger amounts of phospholipids (DPPC) were added, the morphology is transformed from thiolated-Au clusters into vesicle forms. The structural transition could be induced by the presence of lipid bilayers (liposomes) that could engulf the lipid wrapped thiolated-Au NP clusters to form such lipid bilayer vesicles loaded with several thiolated-Au NP clusters in the lipid membrane. The in-situ time-resolved study on the structural transformation by mixing lipid wrapped thiolated-Au NPs with liposomes showed that such a process would take hours to complete. The further observation of Au-8C NP dispersed by DPPC shows there’re two phases occurred as Au-8C aggregation, amorphous and crystalline. The phase can only be influenced by the initial concentration of sample chloroform state instead of thermal treatment or adding 8C thiol. And we believe that the crystalline phase will be superlattice structure made by Au-8C packing.