Characterization of bio-synthesized magnetic nanoparticles

Magnetic nanoparticles have potential utility in a variety of applications ranging from ferrofluids to highly sensitive transduction mechanisms for monitoring and controlling biological activities at the molecular level. This paper describes a novel methodology for bacterial synthesis of a wide range of magnetite-based magnetic nanoparticles. First, this approach is highly scalable and low cost enabling production of large volumes of nanoparticles. Second, like the chemical co-precipitation technique, biologically synthesized materials have the ability to dope magnetite with a wide range of elements enabling fine control over magnetic and thermal properties of the particles. Third, unlike chemical co-precipitation techniques which restrict particle sizes below 20 nm, bacterial synthesis enables control of particle sizes from 10 nm to 100 nm. Finally, we show that some forms of the bio-synthesized materials have a significantly higher saturation magnetization than typical chemically synthesized materials.