Toward Multifunctional Clickable Diamond Nanoparticles

Nanodiamonds (NDs) are among the most promising new carbon based materials for biomedical applications, and the simultaneous integration of various functions onto NDs is an urgent necessity. A multifunctional nanodiamond based formulation is proposed here. Our strategy relies on orthogonal surface modification using different dopamine anchors. NDs simultaneously functionalized with triethylene glycol (EG) and azide (-N-3) functions were fabricated through a stoichiometrically controlled integration of the dopamine ligands onto the surface of hydroxylated NDs. The presence of EG functionalities rendered NDs soluble in water and biological media, while the -N-3 group allowed postsynthetic modification of the NDs using click chemistry. As a proof of principle, alkynyl terminated di(amido amine) ligands were linked to these ND particles.