Monodisperse magnetic nanoparticles for biomedical applications

Magnetic nanoparticles that are superparamagnetic with high saturation moment have great potential for biomedical applications. Solution-phase syntheses have recently been applied to make various kinds of monodisperse magnetic nanoparticles with standard deviation in diameter of less than 10%. However, the surface of these nanoparticles is coated with a layer of hydrocarbon molecules due to the use of lipid-like carboxylic acid and amine in the syntheses. Surface functionalization leads to the formation of water-soluble nanoparticles that can be further modified with various biomolecules. Such functionalization has brought about several series of monodisperse magnetic nanoparticle systems that have shown promising applications in protein or DNA separation, detection and magnetic resonance imaging contrast enhancement. The goal of this mini review is to summarize the recent progress in the synthesis and surface modification of monodisperse magnetic nanoparticles and their applications in biomedicine. (C) 2007 Society of Chemical Industry.