Production of functional magnetic nanoparticles and characterization with optical polarization method for biomedical applications

Magnetic nanoparticles attracted most of the attention in recent years. They have properties such as magnetic behavior exhibited towards the magnetic field and attachment to molecules such as DNA and proteins with bio-compatibility. In addition, they have adjustable size which is promising to many areas such as optics, electronics, medicine, drug delivery, diagnosis and treatment of disease. Therefore, in this study the production, functionalization, and characterization of magnetic nanoparticles were done. Magneto-optic effects of nanoparticles were also investigated while binding with DNA. Production of nanoparticles were realized in nitrogen atmosphere due to the obtained smaller size of the nanoparticles by using co-precipitation method. The surface of produced magnetite (Fe3O4) particles were functionalized with molecules such as TMA, Oleic acid and APTES to prevent the precipitation and to bind them with the other molecules actively. Macro sized particles that are within the synthesized magnetic nanoparticles were separated by centrifugal method. Structural, size and magnetic characteristics and magneto-optical properties of magnetite nanoparticles were analyzed by DLS, XRD, VSM and dichroism spectroscopy measurement system which was designed in this study respectively. At the same time, double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA) were combined with magnetic nanoparticles. Also, the study was extended to magneto- optical properties of this combined systems with polarization dependent for applied different magnetic field values. Keywords: Magnetic nanoparticles, Fe3O4, dichroism, ds-DNA, ss-DNA, magneto-optic.