The Effectiveness of Banana Peels and Copper Oxide Nanoparticles in Inhibiting Staphylococcus aureus and Klebsiella pneumoniae

Abstract

Objective: This study aimed to evaluate the antibacterial activity of banana peel extract (BPE) and green-synthesized copper oxide nanoparticles (CuO-NPs) against Staphylococcus aureus and Klebsiella pneumoniae, and to investigate their synergistic effects.

Methods: Banana peel extract was prepared using Soxhlet extraction, while CuO nanoparticles were synthesized using plant-derived bioactive compounds as natural reducing and stabilizing agents. The synthesized nanoparticles were characterized using UV–Vis and FTIR spectroscopy. GC–MS analysis was performed to identify the major bioactive compounds in the extract. Antibacterial activity and synergistic interactions were assessed using minimum inhibitory concentration (MIC) and checkerboard assays.

Results: UV–Vis analysis confirmed CuO nanoparticle formation with an absorption peak at 971 nm, while FTIR analysis revealed functional groups involved in nanoparticle stabilization. GC–MS analysis identified several antioxidant and reducing compounds in banana peel extract. The combined use of BPE and CuO-NPs showed enhanced antibacterial activity, particularly against S. aureus, with a strong synergistic effect (FICI = 0.375). A lower antibacterial effect was observed against K. pneumoniae.

Conclusion: The findings suggest that banana peel-mediated green synthesis of CuO nanoparticles is an eco-friendly and promising strategy for future antimicrobial and biomedical applications.