1School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, United States
Chemical doping is implemented in order to disrupt magnetic moment coupling within a crystal and render a paramagnetic nanoparticle. Tunstate is introduced inside the apoferritin cavity as a dopant of the iron oxide core. The crystal surface un-coupled moments are in close contact with the surrounding water protons to reduce overall longitudinal relaxation. The paramagnetic apoferritin composite resulted in a particle r1 of 4870mM-1s-1 and r2/r1 of 1.86 making them a sensitive nanoparticle agent for in vivo molecular MRI.