ABSTRACT BACKGROUND: In recent years, extensive studies have been performed on magnetite nanoparticles (MNPs) and their applications, which have shown the current project to be one of the major applications by laboratory results.METHODS: The nanoparticles synthesized in this project were deposited by the co-precipitation method, which structure was identified by analyzers such as SEM, FT-IR, and EDX. The aim of this project is the adsorption and fixation of biomolecule (BSA (bovine serum albumin) protein on the surface of magnetic nanoparticles.RESULTS: The adsorption results by electrophoresis and spectrophotometric analyzers showed an absorption rate above 55% ie; 55% of the protein is fixed on the MNPs nanoparticles. This absorption is due to the high level of functionality of magnetic nanoparticles for adsorption of protein. The results of the EDX analysis also show the possible electrostatic bonding between the nanoparticles and the protein, this is derived from –OH with –NH2 groups of the nanobiocompound (MNPs /protein). After bonding, the two are easily separated.CONCLUSION: In this project, the Fe3O4 nanoparticles was synthesized and identified by SEM, FT-IR, and EDX analyzers and finally reacted with the BSA protein (for the absorption of protein on MNPs) under experimental conditions at a standard temperature of 25° C. The results showed that about 55% of the protein was fixed on magnetic nanoparticles.KEYWORDS:  Magnetic nanoparticles; Spectrophotometer and Electrophoresis analysis; Electrostatic bonding