Green synthesis of Carbon dot-Copper Oxide nanocomposite using Millingtonia Hortensis leaf extract: Characterization and antimicrobial studies

A green synthesis technique was used to produce a Carbon dot Copper Oxide (MHCD@CuO) nanocomposite using Millingtonia hortensis leaf extract as a stabilizing and reducing agent. Nanocomposite characterization involved UV-Vis, XRD, SEM-EDX, FTIR, and XPS. The average crystalline size from XRD is 28.3 nm, and SEM shows nearly spherical nanoparticles with few pencil-like forms (S1). Cu, O, C, and N were found in the XPS, corroborating the FTIR peaks of active functional groups involved in stabilization and bioactivity. The well-diffusion method was utilized to assess the antibacterial activity of MHCD@CuO against Escherichia coli, Salmonella enterica Typhimurium, Staphylococcus aureus, Streptococcus pyogenes, and Aspergillus niger. The inhibition zones were equivalent to reference antimicrobial For Streptococcus pyogenes, the MIC was 15.62 µg/mL (most susceptible), but for other bacterial strains, it was 31.25 µg/mL. These results highlight MHCD@CuO as potent and green antimicrobial candidate with potential in addressing antibiotic resistance.