Green synthesis of Cu/Cu₂O nanoparticles using Ageratum conyzoides leaf extract and their antibacterial activity

Abstract

Copper nanoparticles have attracted significant interest due to their antibacterial activities in many different applications. This study introduces the utilization of leaf extract of Ageratum conyzoides, a widely‐known plant in Vietnam, and evaluates its antimicrobial efficacy through the eco‐friendly synthesis of Cu/Cu2O nanoparticles (NPs) using CuSO4 as a precursor. In this research, the Ageratum conyzoides leaf extract serves dual purposes, acting as both a reducing agent and a stabilizing agent for Cu/Cu2O nanoparticles. The synthesis of Cu/Cu2O NPs was successfully developed and their optical properties were analyzed using UV–visible spectroscopy. The structural characterization of synthesized nanoparticles was carried out using X‐ray diffraction while transmission electron microscopy facilitated morphological observations. In addition, energy‐dispersive X‐ray analysis confirmed the presence of copper, and Fourier transform infrared spectroscopy confirmed the presence of functional groups on the nanoparticle surface. The results revealed that the synthesized Cu/Cu2O NPs were spherical morphology with an average size of around 5 nm observed from TEM images. Furthermore, the results show the ability to inhibit the growth of various pathogenic microorganisms of the synthesized nanoparticles by around 30% and exhibit potential antibacterial properties.