Magnetic Decoupling of Surface Fe super(3+) in Magnetite Nanoparticles upon Nitrocatechol-Anchored Dispersant Binding

Bind and distort: NitroDOPA, an anchor shown to irreversibly couple dispersants and functional groups to superparamagnetic Fe sub(3)O sub(4) nanoparticles, can magnetically decouple Fe super(3+) in a nanoparticle surface layer. The strong binding of nitroDOPA distorts the Fe super(3+) ligand field. This ESR finding sheds light on an important binding mechanism of anchors used for nanoparticle surface modification (see graphic).