Abstract
We have discussed the applications of silica nanoparticles doped with either magnetic materials or fluorescent dye molecules. Both the Stober and water-in-oil microemulsion systems were used for the nanoparticle's preparation. These nanoparticles are uniform and can be made with a large size range from a few nanometers to hundreds of nanometers. The silica surface displays an easily modifiable chemistry with a variety of biomolecules, and can be reproducibly synthesized. Silica nanoparticles have been successfully used in bioseparation of nucleic acids, peptides and cells. Mass spectroscopy has been used for peptide analysis, and dye doped nanoparticles have been used as ultrasensitive labels in bioanalysis. The nanoparticles demonstrated great potential in separating and analyzing biological molecules. (c) 2006 Elsevier Ltd. All rights reserved.