Surface functionalization of nanodiamonds for biomedical applications.

Nanodiamonds (NDs), recent member of carbon nanomaterial, are nano-scale carbon allotropes having versatile surface chemistry. NDs are commonly synthesized by detonation and followed by purification, surface modification and surface functionalization. Surface functionalization of NDs enhances safety, bio-compatibility and lowers toxicity. It involves initial surface homogenization followed by attachment of ligand on NDs which increases hydrophobicity, reduces surface charge and improves surface chemistry. Generally, surface functionalization is carried out by covalent and non-covalent attachment and in biomedical applications various functional groups, biomolecules, or polymers can be attached to NDs. This review is focused on surface functionalization methods for NDs and their biomedical applications. Surface functionalization is beneficial to improve physicochemical properties of NDs which may be further utilized in diagnosis and targeted drug delivery.