Surface design of core–shell superparamagnetic iron oxide nanoparticles drives record relaxivity values in functional MRI contrast agents

Core-shell hydrophilic superparamagnetic iron oxide (SPIO) nanoparticles, surface functionalized with either terephthalic acid or 2-amino terephthalic acid, showed large negative MRI contrast ability, validating the advantage of using low molecular weight and π-conjugated canopies for engineering functional nanostructures with superior performances.