Multifunctional iron oxide nanoparticles for biomedical applications

Multifunctional nanoparticles have attracted a lot of attention since they can combine interesting properties like magnetism, fluorescence or plasmonic effects. As a core material, iron oxide nanoparticles (NP) have been the subject of intensive research. These cost-effective and non-toxic particles are used nowadays in many applications. However, customized functionalization of their surface is not trivial. We developed a hetero bifunctional PEG ligand that can be used to introduce functional groups (carboxylic acids) onto the surface of the NP. Via click chemistry, a siloxane functionality was added to this ligand, for a subsequent covalent ligand exchange reaction. The functionalized NP have an excellent colloidal stability in complex environments like buffers and serum or plasma. Antibodies were coupled to the introduced carboxylic acids and their availability was assessed by SPR measurements. These NP-antibody bioconjugates were brought into contact with bacteria for magnetic separation experiments.status: publishe