Gd(III)-Grafted Detonation Nanodiamonds for MRI Contrast Enhancement

We report on the first 1H NMR relaxation and magnetic resonance imaging (MRI) study of aqueous suspensions of detonation nanodiamond (DND) grafted by Gd(III) ions. In contrast to Gd(III)–ND conjugates implemented via organic species, Gd(III) ions were directly grafted to the surface of DND particles. Such Gd(III)-grafted DND particles significantly shorten spin–lattice (T1) and spin–spin (T2) relaxation times of water protons providing relaxivities of r1 = 33.4 and r2 = 332 mM–1 s–1, which considerably exceed most of those reported in the literature. It makes the Gd(III)-grafted DND complexes attractive for use as novel MRI contrast agents.