Nanodiamonds

Definition

Nanodiamonds are carbon nanoparticles with truncated octahedral architecture (Fig. 8.1) that are about 2–8 nm in diameter and can deliver a wide range of therapeutics, including small molecules, proteins, and nucleic acids . Nanodiamond particles with the smallest monocrystalline size (about 4 nm), also called detonated nanodiamonds are produced by detonation of carbon-containing explosives followed by purification.

Structure

The
structure of nanodiamond can be assumed to be consisting of three
sections, namely, outer surface of carbon atom with functional groups,
central part with sp³-hybridized carbon atoms, and the inner
diamond core structure. The outer shell of nanodiamond has hydrogenated
surface (H and OH groups) and diameter of 0.6 nm. It contains ~61% of all carbon. The diameter of inner core is up to 2.4 nm. Approximately 40% of carbon is located in the core and inner layer of the nanodiamond. The TEM micrograph reveals the microstructure of ultra-dispersed nanodiamond particles with narrow particle size distribution. The nanoparticle size is below 15 nm

Application in medical sciences

Nanodiamonds are used as antimicrobial agents and delivery vehicles
for vaccines and drugs because they are biocompatible and small in size
and shape, enabling them to penetrate cells without causing damage.