A Gd(III)-nanodiamond conjugate [Gd(III)-ND] was prepared and characterized, enabling detection of nanodiamonds by MR imaging. The Gd(III)-ND particles significantly reduced the T1 of water protons with a per-Gd(III) relaxivity of 58.82 ± 1.18 mM−1 s−1 at 1.5 T (60 MHz). This represents a 10-fold increase compared to the monomer Gd(III) complex (r1 = 5.42 ± 0.20 mM−1 s−1) and is among the highest per-Gd(III) relaxivities reported.

Gd(III)-Nanodiamond Conjugates for MRI Contrast Enhancement