Dopamine as A Robust Anchor to Immobilize Functional Molecules on the Iron Oxide Shell of Magnetic Nanoparticles

We report on the use of dopamine (DA) as a robust molecular anchor to link functional molecules to the iron oxide shell of magnetic nanoparticles. Using nitrilotriacetic acid (NTA) as the functional molecule, we created a system with an M/Fe₂O₃-DA-NTA (M = Co or SmCo_5.2) nanostructure, which possesses high stability and specificity for separating histidine-tagged proteins. The well-established biocompatibility of iron oxide and the robust covalent bonds between DA and Fe₂O₃ render this strategy attractive for constructing biofunctional magnetic nanoparticles containing iron oxide. Copyright © 2004 American Chemical Society.