Development of Nanomedicine from Copper Mine Tailing Waste: A Pavement towards Circular Economy with Advanced Redox Nanotechnology

Copper, the essential element required for the human body is well-known for its profound antibacterial properties, yet salts and oxides of copper metals in the copper mine tailings are reported to be a big burden in the modern era. Among other copper oxides, CuO, in particular, is known to have beneficial effects on humans, while its slight nanoengineering viz., surface functionalization of the nanometer-sized oxide is shown to make some paradigm shift using its inherent redox property. Here, we have synthesized nanometer-sized CuO nanoparticles and functionalized it with a citrate ligand for an enhanced redox property and better solubility in water. For structural analysis of the nanohybrid, standard analytical tools, such as electron microscopy, dynamic light scattering, and X-ray diffraction studies were conducted. Moreover, FTIR and UV-VIS spectroscopy studies were performed to confirm its functionalization. The antibacterial study results, against a model bacteria (S. hominis), show that CuO nanohybrids provide favorable outcomes on antibiotic-resistant organisms. The suitability of the nanohybrid for use in photodynamic therapy was also confirmed, as under light its activity increased substantially. The use of CuO nanoparticles as antibiotics was further supported by the use of computational biology, which reconfirmed the outcome of our experimental studies. We have also extracted CuO nanogranules (top-down technique) from copper mine tailings of two places, each with different geographical locations, and functionalized them with citrate ligands in order to characterize similar structural and functional properties obtained from synthesized CuO nanoparticles, using the bottom-up technique. We have observed that the extracted functionalized CuO from copper tailings offers similar properties compared to those of the synthesized CuO, which provides an avenue for the circular economy for the utilization of copper waste into nanomedicine, which is known to be best for mankind.