Nanodiamond
Detonation is often performed in a sealed, oxygen-free, stainless steel chamber and yields a mixture of nanodiamonds averaging 5 nm and other graphitic compounds.
[10] Because detonation synthesis results in a mix of nanodiamond particles and other graphitic carbon forms, extensive cleaning methods must be employed to rid the mixture of impurities.
[12] In addition, high-yield synthesis of fluorescent nanodiamonds can be achieved by grinding electron-irradiated cubic crystalline diamond obtained from nitrogen-containing or nitrogen-free carbon precursors.
[17] Nanodiamonds share the hardness and chemical stability of visible-scale diamonds, making them candidates for applications such as polishes and engine oil additives for improved lubrication.
[3] Diamond nanoparticles have the potential to be used in myriad biological applications and due to their unique properties such as inertness and hardness, nanodiamonds may prove to be a better alternative to the traditional nanomaterials currently utilized to carry drugs, coat implantable materials, and synthesize biosensors and biomedical robots.
[23] Studies have shown that small photoluminescent diamond nanoparticles that remain free in the cytosol are excellent contenders for the transport of biomolecules.
[24] Nanodiamonds containing nitrogen-vacancy defects have been used as an ultrasensitive label for in vitro diagnostics, using a microwave field to modulate emission intensity and frequency-domain analysis to separate the signal from background autofluorescence.
[25] Combined with recombinase polymerase amplification, nanodiamonds enable single-copy detection of HIV-1 RNA on a low-cost lateral flow test format.
[21] In addition, the ability to surface functionalize nanodiamonds of small diameters provides various possibilities for diamond nanoparticles to be utilized as biolabels with potentially low cytotoxicity.
[21] Decreasing particle size and functionalizing their surfaces[21] may allow such surface-modified diamond nanoparticles to deliver proteins, which can then provide an alternative to traditional catalysts.
The sensors can be used at room temperature, and since they consist entirely of carbon, they could be injected into living cells without causing them any harm, Paola Cappellaro says.
Boron-doped diamond (BDD) produced by energy-assisted (plasma or hot filament, HF) Chemical Vapor Deposition (CVD) processes is a good candidatein Dopamine detection, however it is not selective towards some interferents.
This issue, can be overcome via further post-synthesis treatments for BDD surface modifications including anodization, hydrogen plasma, etching into porous forms, carbon-based nanomaterials, polymer films and nanoparticles.
Recent studies,[28] propose a new approach for the realization of Titanium doped diamond-based electrodes with a native selectivity towards dopamine, through substrate pre-treatments (lapping, electropolishing and chemical etching) instead of post-process treatments.
[29] Those modifications, which can be summarised as an increase in the ionic conductivity of the system, thus of a decrease in the impedance, are likely due to the presence of functional groups on the nanodiamond particle surface.
