| Popis: |
Fabrication of magnetic materials with a high level of control down to the nanoscale is a current synthetic challenge. Nature is able to achieve this level of precision under ambient conditions and in aqueous solutions, by using specific biomineralisation proteins to produce highly monodisperse magnetic nanoparticles within the magnetosome organelles of magnetotactic bacteria. This chapter explores the use of such proteins outside the magnetosome, in synthetic magnetite formation reactions, where their ability to control and affect the nanoparticle products in terms of size, morphology and material purity is demonstrated. Understanding how these proteins function to achieve their activity is of particular interest, and we bring together the current literature to assess the roles of sequence and self-assembly in this process. In addition to the magnetosome-derived proteins, researchers are expanding the biological toolkit of available magnetic material mineralising proteins by using and adapting others. We investigate a number of these proteins including ferritin, heat shock protein cages and even small peptides. These can be used without modification, or they can be engineered to contain artificial binding sequences, selected via processes such as phage display. Developing new mineralising sequences allows proteins to be used with materials which are not naturally occurring, such as the platinum alloys of cobalt and iron, which have industrially desirable magnetic characteristics. The proteins/peptides covered in this chapter have the potential to aid future production of precise magnetic nanoparticles for diverse applications in the biomedical and data storage fields. |
