Biocompatible Nanodiamonds Derived from Coal Washery Rejects: Antioxidant, Antiviral, and Phytotoxic Applications

Coal washery rejects (CWRs) are a major byproduct produced in coal washery industries. We have chemically derived biocompatible nanodiamonds (NDs) from CWRs toward a wide range of biological applications. The average particle sizes of the derived blue -emitting NDs are found to be in the range of 2-3.5 nm. High-resolution transmission electron microscopy of the derived NDs depicts the crystalline structure with a d-spacing of 0.218 nm, which is attributed to the 100 lattice plane of a cubic diamond. The Fourier infrared spectroscopy, zeta potential, and X-ray photoelectron spectroscopy (XPS) data revealed that the NDs are substantially functionalized with oxygen -containing functional groups. Interestingly, the CWR-derived NDs exhibit strong antiviral properties (high inhibition of 99.3% with an IC50 value of 7.664 mu g/mL) and moderate antioxidant activity that widen the possibility of biomedical applications. In addition, toxicological effects of NDs on the wheatgrass seed germination and seedling growth showed minimal inhibition (<9%) at the highest tested concentration of 300.0 mu g/mL. The study also provides intriguing prospects of CWRs for the creation of novel antiviral therapies.

Automated summary

Coal washery rejects (CWRs) are chemically transformed into biocompatible nanodiamonds (NDs) with blue light emission, exhibiting strong antiviral properties and moderate antioxidant activity for potential biomedical applications. The NDs derived from CWRs possess a crystalline structure with a 100 lattice plane of a cubic diamond, and are substantially functionalized with oxygen-containing functional groups. Additionally, they show minimal inhibition on wheatgrass seed germination and seedling growth, indicating low toxicity at the highest tested concentration.