A nanomaterial can include an outer layer including a ligand. The ligand can include a first monomer unit including a first moiety having affinity for a surface of the nanocrystal, a second monomer unit including a second moiety having a high water solubility, and a third monomer unit including a third moiety having a selectively reactive functional group or a selectively binding functional group. The ligand can be a random copolymer.