Cellular distribution and degradation of cobalt ferrite nanoparticles in Balb/3T3 mouse fibroblasts

► SR-XRF is used to map CoFe2O4 nanoparticles (NPs) distribution at sub-cellular level. ► CoFe2O4 NPs are mainly confined in the perinuclear region of the cell. ► SR-XRF microspectroscopy data show chemical degradation of CoFe2O4 NPs. ► Mechanisms of NPs toxicity can be investigated by SR-XRF at sub-cellular level.