Phase-pure iron oxide nanoparticle MPI tracers: Comparison of alternative thermal decomposition synthesis strategies

MPI signal intensity and spatial resolution are highly dependent on the median core size and size monodispersity of the tracers[1]. Increasing the core size of the highly monodisperse tracers to about 25-27nm (i.e close to the superparamagnetic to ferromagnetic transition at room temperature and 100s measurement time, assuming bulk anisotropy) significantly improves the MPI spatial resolution and signal intensity[1]. However, the performance of these larger core sizes is also highly dependent on their crystalline structure and phase (magnetite, maghemite, or wüstite) purity. Here, we discuss important factors that should be considered for size-tuned synthesis of single crystalline magnetite nanoparticles (NPs) through the thermal decomposition of three common organometallic iron precursors.