Eco-friendly synthesis of antibacterial CuO nanoparticles using garlic bulb extract

The article explores the antibacterial characteristics of copper oxide (CuO) nanoparticles synthesized through an eco-friendly method utilizing garlic bulb (Allium sativum) extract. Various characterization techniques, including X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, ultraviolet (UV)–visible spectroscopy, and Fourier-transform infrared spectroscopy (FTIR), were employed to analyze the CuO nanoparticles. These nanoparticles were found to have crystalline diameters of 25, 31, and 51 nm, respectively, as determined by means of the Scherrer equation, modified Scherrer formula, and Williamson–Hall analysis. UV–visible spectroscopy confirmed their synthesis by showing an absorption peak at 358 nm. The FTIR spectra specified the presence of various phytochemicals on the nanoparticle surfaces, characterized by distinct functional groups, for instance, carbonyl and phenolic groups. The natural compounds in garlic extract contributed to the reduction and stability of the CuO nanoparticles. The antibacterial activity of the synthesized CuO nanoparticles was evaluated against gram-negative bacteria, Pseudomonas aeruginosa (MTCC 1688) and Escherichia coli (MTCC 443), along with gram-positive bacteria, Cutibacterium acnes (MTCC 843) and Staphylococcus aureus (MTCC 96). The CuO nanoparticles demonstrated maximum inhibition zones of 25 ± 0.88 mm against C. acnes and 21 ± 0.58 mm against E. coli.