The role of optical properties in enhancing antimicrobial activity of Mg0.94Cu0.06O nanoparticles

This study explores the optical properties and antibacterial efficacy of copper-doped magnesium oxide (Mg₀.₉₄Cu₀.₀₆O) nanoparticles synthesized via the sol-gel method. Using magnesium and copper precursors with citric acid as a chelating agent, the nanoparticles were synthesized through gelation, drying, and calcination at 500 °C. Structural characterization using XRD confirmed the formation of a crystalline cubic MgO phase with copper doping, while FTIR analysis revealed vibrational modes indicative of metal-oxide bonding. UV-Vis spectroscopy showed a direct bandgap energy of 2.25 eV, suggesting enhanced optical properties due to copper incorporation. Antibacterial activity was evaluated against Staphylococcus aureus using the disk diffusion method, with the nanoparticles demonstrating a significant inhibition zone of 26 mm. The enhanced antibacterial performance is attributed to copper\'s ability to generate reactive oxygen species, which disrupt bacterial membranes. These findings highlight the synergistic role of magnesium and copper in improving the material\'s multifunctional properties, making Mg₀.₉₄Cu₀.₀₆O nanoparticles promising candidates for antimicrobial and biomedical applications.