The production of magnetic nanoparticles of utmost quality for biomedical imaging requires several steps, from the synthesis of highly crystalline magnetic cores to the attachment of the different molecules on the surface. This last step probably plays the key role in the production of clinically useful nanomaterials. The attachment of the different biomolecules should be performed in a defined and controlled fashion, avoiding the random adsorption of the components that could lead to undesirable byproducts and ill-characterized surface composition. In this work, we review the process of creating new magnetic nanomaterials for imaging, particularly for the detection of atherosclerotic plaque, in vivo. Our focus will be in the different biofunctionalization techniques that we and several other groups have recently developed. Magnetic nanomaterial functionalization should be performed by chemoselective techniques. This approach will facilitate the application of these nanomaterials in the clinic, not as an exception, but as any other pharmacological compound.The authors thank the Spanish Ministry of Science (SAF2011-25445), the Comunidad de Madrid (S2010/BMD-2326, Inmunothercan-CM, NANOCOPD-CIBERES-CIBERBBN-SEPAR), and the EU 7th Framework Program (FP7-PEOPLE-ITN-264864 Pinet and FP7-PEOPLE-2013-ITN CardioNext).S
