Self-assembly of phospholipid-PEG coating on nanoparticles through dual solvent exchange.

We coated nanoparticles including iron oxide nanoparticles and quantum dots with phospholipid-PEG using the newly developed dual solvent exchange method and demonstrated that, compared with the conventional film hydration method, the coating efficiency and quality of coated nanoparticles can be significantly improved. A better control of surface coating density and the amount of reactive groups on nanoparticle surface is achieved, allowing conjugation of different moieties with desirable surface concentrations, thus facilitating biomedical applications of nanoparticles.