Multifunctional iron oxide nanoparticles for biomedical applications

Abstract

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 have been the subject of intensive research. These cost-effective and non-toxic particles are used nowadays in many applications. We developed a heterobifunctional 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 nanoparticles have an excellent colloidal stability in complex environments like buffers and serum or plasma. Antibodies were coupled to the introduced carboxylic acids and these NP-antibody bioconjugates were brought into contact with Legionella bacteria for magnetic separation experiments.

Amino-Termination of Silicon Carbide Nanoparticles

“…We note that the NH 2 -terminated silicon dioxide NPs with OH groups on the surface show also negative zeta potential values [ 34 ] which is very similar to our system. The OH groups are also protic groups in acid-base equilibrium on the surface [ 35 ], and the OH-terminated surface can provide more negative value than the COOH-terminated one [ 36 ].…”