Size controlled magnetite nanoparticles and their drug loading ability

Magnetite nanoparticles (MNPs) were synthesized by using coprecipitation method with a reaction between the FeCl2/FeCl3 solution and the ammonia water. The size of the MNPs could be controlled from 10.0 to 14.6 nm by changing the concentration of the solutes. The particles were superparamagnetic at room temperature. The saturation magnetization of the MNPs increased with increasing concentration of reactants. The magnetite nanoparticles were coated with a single layer of oleic acid (OA) to have a hydrophobic surface or with a double layer of oleic acid/sodium dodecyl sulfate (OA/SDS) to have hydrophilic surface. The coated particles could be dispersed in n-Hexane or water. The OA/SDS-coated nanoparticles were used to load an antibiotic drug, chloramphenicol (Cm). Three weight percent of Cm could be loaded onto the OA/SDS coated nanoparticles, which is much higher than amount that can be loaded using the traditional drug loading method.