Computational and experimental study of CuO–ZnO nanocomposite using the plant Peganum harmala L. and their antifungal, antibacterial applications

Abstract

The rapid emergence of AMR necessitates the development of novel, sustainable therapeutic agents. This study reports the green synthesis of copper-decorated zinc oxide (CuO-ZnO) nanocomposite using an aqueous leaf extract of Peganum harmala L., which served as a reducing and capping agent. A quantitative EDX analysis confirmed a high loading of Cu of 24.25% (7.09%) mass. Characterization showed that the average primary particle size was 29 ± 1.3 nm, and that the structures were crystalline and hexagonal, known as wurtzite. The nanocomposite exhibited a positive zeta potential of + 47.2 ± 4.24 mV, indicating good colloidal stability. A typical absorption peak at 372 nm was observed using UV-visible spectroscopy. The CuO-ZnO nanocomposite showed significant dose-dependent antibacterial activity with Minimum Inhibitory Concentrations (MIC) of 50 µg/mL, 70 µg/mL, and 80 µg/mL for Staphylococcus epidermidis, Salmonella typhi, and Klebsiella pneumoniae, respectively. The synthesized CuO-ZnO nanocomposite exhibited significant antifungal activity, inhibiting the linear growth of Aspergillus flavus and Fusarium oxysporum by 87.67 mm and 74.33 mm, respectively. While computational models suggest localized structural integration, the system is described as a copper-decorated zinc oxide network, pending high-resolution phase-state verification. This integrated study highlights the potential of P. harmala-mediated CuO-ZnO nanocomposite as an eco-friendly antimicrobial agent for biomedical applications.