Graphitic Carbon Coated Magnetite Nanoparticles for Dual Mode Imaging and Hyperthermia

Correlating the optical properties to the magnetic properties in superparamagnetic iron oxide (Fe3O4) nanoparticles (SPIONs) will be a boost for future biomedical applications. However, designing such SPIONs without altering its properties is a real challenge. Here, we demonstrate the engineering of the magneto-fluorescent properties simply by tuning the carbon structure in graphitic carbon coated SPIONs. By synthesizing three distinct nanostructures in an easy single step process and studying the in depth structural–functional relationship, we found that the thickness of carbon shell decides the fate of magneto-fluorescent characteristics in SPIONs. Single particle fluorescence data show that the number of emissive photon increases substantially with the increase in the thickness of carbon shell, albeit, the observed relaxivity was enough to get high quality magnetic resonance imaging. The ex vivo magnetic hyperthermia results advanced the use of SPIONs as a single platform for cancer theranostics.