Magnetic iron oxide coated hollow glass microspheres were developed in response to an identified opportunity in the diagnostic sector. It involved the immobilisation of superparamagnetic iron oxide particles on the surface of a hollow glass sphere using a biological binder molecule.

The superparamagnetic nature of the coating meant that the particles would come to a magnet, but not retain magnetism after release and so would redisperse easily. A thin silica layer on top of the iron oxide helped protect the magentic layer and also provided chemical functionality for the coupling of biological ligands such as antibodies for target capture.

Researchers have successfuly applied hollow glass microsphere to the extraction and quantitation of marine biotoxins from shellfish and have found the material to offer a number of advantages in this area.