(172c) Application Of Functionalized Magnetic Nanoparticles In Separation Technology

Magnetic particles are routinely applied in biochemistry separations. Unfortunately their application is often limited due to high costs, poor stability and low binding capacities.

Here, we use carbon coated metallic nanoparticles prepared by reducing flame spray synthesis. The magnetic nanoparticles are highly air stable until 190°C. In a one step synthesis the carbon surface of the magnetic beads was functionalized with chlorine- or nitrogroups. Due to the strength of the generated carbon-carbon bond the links are stable under a wide variety of reaction conditions.

The derivatized material was separated within seconds from the reaction mixture using a permanent magnet. Coupling a molecule of interest to the functionalized particles generates an easily separate-able molecule for further treatments. The low costs and particle stability favor this preparation method and material for large-scale separation application of biological molecules such as proteins and antibodies.

The left figure shows the powder mass gain upon oxidation measured by thermogravimetry in air of pristine carbon coated cobalt nanoparticles (solid line) and chlorobenzene functionalized nanobeads (broken line). The scheme in the middle shows covalently functionalized metallic and magnetic nanoparticles as a platform for inexpensive magnetic separations in synthesis of biological molecules. The TEM picture on the right side presents carbon-coated cobalt particles.

References

[1] R. N. Grass, E. K. Athanassiou, W. J. Stark, Angewandte Chemie 2007, in print.

[2] R. N. Grass, W. J. Stark, J. Mater. Chem. 2006, 16, 1825.

[3] R. N. Grass, M. Dietiker, R. Spolenak, W. J. Stark, Nanotechnology 2007, 18, 035703.