Magnetic iron oxide coated hollow glass microspheres (FERROSPHERES) were developed by MTL in response to an identified opportunity in the diagnostic sector.  This was the first microsphere-based product produced by MTL and 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.

The functionalised, buoyant, magnetic particles are marketed by MTL as a platform for assessment in immuno tests and have been used extensively in the area of marine biotoxin research by MTL customers.

Researchers at The Queen’s University of Belfast have successfuly applied MTL’s Ferrospheres to the extraction and quantitation of marine biotoxins from shellfish and have found the material to offer a number of advantages in this area. The same group has also examined the possibility of using Ferrospheres in the large scale harvesting of marine biotoxin standards:

Devlin, R.; Campbell, K.; Kawatsu, K.; Elliott, C. Studies in the Use of Magnetic Microspheres for Immunoaffinity Extraction of Paralytic Shellfish Poisoning Toxins from Shellfish. Toxins 2011, 3, 1-16.  (Link to paper)

Devlin, R.; Campbell, K.; Kawatsu, K.; Elliott, C. Physical and immunoaffinity extraction of paralytic shellfish poisoning toxins from cultures of the dinoflagellate Alexandrium tamarnse. Harmful Algae, 2011, 10, 542-548. (Link to paper)