Nature-Inspired Antimicrobial Agents: Cinnamon-Derived Copper Oxide Nanoparticles for Effective Aspergillus Niger Control.

The emergence of resistant bacterial and fungal strains poses significant challenges in various industrial processes including food, medicines, and leather industry. It necessitates the development of novel and effective antimicrobial agents. In the present work, we have developed an ecofriendly and sustainable approach to synthesize silver-doped copper oxide nanoparticles by using cinnamon bark extract (C-CuO/Ag). The nanoparticles were characterized via UV-visible spectroscopy at 190-800 nm, FT-IR, SEM-EDAX, XRD, and further subjected to determine antimicrobial potential, minimum inhibitory concentration (MIC), and anti-biofilm potential against both bacterial and fungal species. UV-visible spectrum showed maximum absorption at 210 nm in ultraviolet range and 419 nm in visible range. Various strong and weak peaks were obtained in FT-IR spectra, which defined the presence of corresponding functional groups in C-CuO/Ag nanoparticles. SEM analysis revealed the tightly packed confirmation, while EDS confirmed the elemental analysis of C-CuO/Ag nanoparticles. XRD spectrum of C-CuO/Ag nanoparticles showed strong diffraction peaks at 2Ө of 31.92˚, 35.67˚, and 48.51˚, which confined with the plane indices of (-110), (111), and (- 202), respectively, while weak diffraction peaks at 2Ө of 56.31˚, 58.9˚, and 77.4˚, which leads to the crystal planes of (202), (- 220), and (311), respectively. Antimicrobial assays showed clear zones of inhibition against microbial strains as maximum inhibition diameter was observed against Aspergillus niger (31.5 ± 0.7 mm) followed by Escherichia coli (30.1 ± 0.3 mm) and Staphylococcus aureus (29.5 ± 0.7 mm). These findings provide support clear evidence that CuO nanoparticles can serve as potent antibacterial and antifungal compounds against highly resistive and pathogenic microbial strains.