Described herein are nanoparticles that are coated with a bilayer of molecules formed from surface binding molecules and amphiphatic molecules. The bilayer coating self assembles on the nanoparticles from readily available materials/molecules. The modular design of the bilayer coated nanoparticles provides a means for readily and efficiently optimizing the properties of the bilayer coated nanoparticle compositions. Also described herein are uses of such nanoparticles in medicine, laboratory techniques, industrial and commerical applications.