One pot Synthesis of Size Controllable Amine Functionalized Core Shell Magnetic Nanoparticles for Use in Microfluidic Flow Separators
Silica coating of magnetic nanoparticles has been widely used as a surface modification strategy to endow various surface functionalization and fast magnetic respond for application in molecular separation and purification. A simple one pot synthesis of amine functionalized core shell magnetic nanoparticles with a tunable shell thickness has been prepared in a reverse microemulsion system. The morphologies and sizes of resulting nanoparticles were confirmed by PXRD spectroscopy and TEM imaging. Nanoparticles prepared by this method are single core dominated and highly monodisperse, and show great potential for use in a closed cycle microfluidic magnetic purification system. To demonstrate this idea, fluorescein was used as a model carboxylate molecule to demonstrate the potential separation ability of Fe3O4@SiO2 NH2 nanoparticles towards cationic targets via UV VIS spectroscopy. The results show that fluorescein molecules can be quickly and quantitatively associated with the magnetic nanoparticles via electrostatic binding, resulting in an average of 2.73 x 103 adsorbed target molecules per nanoparticle. In addition, covalent binding of target molecules to the nanoparticles is also demonstrated.