One aspect of the present invention relates to a permanently linked,
rigid, magnetic chain of particles prepared by sol-gel methods. A second
aspect of the present invention relates to a method of preparing a
permanently linked, rigid, magnetic chain of particles comprising:
coating a core material with one or more polyelectrolyte layers resulting
in a coated particle; further coating the coated particle with a layer of
magnetic nanoparticles resulting in a magnetic particle; coating the
magnetic particle with a layer of a polycationic polyelectrolyte
resulting in a coated magnetic particle; and applying a magnetic field to
the coated magnetic particle in the presence of a metal oxide or metal
oxide precursor capable of undergoing hydrolysis.