This work focused on the development and characterization of nanoparticles, a branch that is constantly growing and through recent research it has been shown that, no matter how small a particle, it can drive great technological advances. Nanoparticles that have a high surface area cover biotechnological, chemical, physical and even electronic areas due to the great versatility present in their structures. Its functionalization is necessary in order to set desirable properties. As practical objectives, magnetic nanoparticles were synthesized from iron (II) and (III) chlorides and sodium hydroxide and later functionalized with APTS and, submitting the samples to analyzes such as X-Ray Diffractions (XRD), Infrared Spectroscopy ( FTIR) and Zeta Potential, in order to confirm the synthesis and functionalization.