Selective binding and magnetic separation of histidine-tagged proteins using Fe3O4/Cu-apatite nanoparticles

Hierarchical Fe3O4@Cu-apatite nanoparticles (NPs) were synthesized via a facile hydrothermal method. The Fe3O4 cores present spherical shape and have a mean diameter of 300nm, and the Cu-apatite shell with thickness of about 50nm is composed of a large number of sheets. Using the high affinity of Cu(2+) on the surface toward histidine tags, the Fe3O4@Cu-apatite NPs can be applied to enrich and magnetically separate histidine tagged (His-tagged) proteins directly from the mixture of lysed cells. Research results indicated that the Fe3O4@Cu-apatite NPs presented negligible nonspecific protein adsorption and high protein binding ability.