Magneto-Optical Properties of Iron Oxide Nanoparticles for Use in Medical Imaging

Due to their non-toxic and magnetic nature, magnetite iron oxide (Fe3O4) nanoparticles have potential uses in biomedical applications such as for magnetic resonance (MR) contrast agents. In this work, the physical properties of rare-earth element doped (Tb and Eu) and undoped iron oxide nanoparticles are optically investigated. Absorption and photoluminescence (PL) from doped and undoped iron oxide nanoparticles in solution show a well-defined excitonic absorption and weak PL. When the nanoparticles are drop cast into thin films, the absorption spectra remains unchanged while the PL disappear, suggesting the thin film creates non-radiative relaxation pathways. Low-temperature absorption measurements are also performed on the undoped iron oxide thin films. To further characterize optical properties of Fe3O4 nanoparticles and other materials, a spectrofluorometer is reconstructed for absorption and PL measurements. This consists of rewiring and controlling three motors, to adjust the slit width and rotate a double monochromator, a photo-gate, and reflective sensor using a micro-controller interface.