A method for stabilizing conjugates between macromolecule and nanoparticle by forming a thin reinforcement layer over the surface of a nanoparticle after macromolecule chains have attached to the surface of the nanoparticle. The stabilized conjugates can be used in a wide range of applications such as in vitro diagnostics, in vivo imaging and therapeutics, which need to be conducted under various severe or harsh conditions.
