Green synthesis of gold-doped ZnFe₂O₄ nanoparticles using Crataegus monogyna leaf extract: characterization, antibacterial, and efficient degradation of methylene blue and eriochrome black T pollutants

In recent years, green chemistry has emerged as an efficient, environmentally friendly, and sustainable approach for nanoparticle synthesis. In this study, we employed a green chemistry method to synthesize ZnFe₂O₄@Au nanoparticles in the presence of a Crataegus monogyna leaf extract. The synthesized nanoparticles were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD) analysis, demonstrating their spherical morphology and homogeneous structure. XRD analysis confirmed the purity of the ZnFe₂O₄@Au nanoparticles. We applied these nanoparticles as nano-catalysts for the degradation of cationic (methylene blue) and anionic (eriochrome black T) pollutants. Under UV irradiation, ZnFe₂O₄@Au nanoparticles exhibited high pollutant degradation efficiency, with 94.3% and 90.8% degradation of methylene blue and eriochrome black T, respectively, within 120 min. Furthermore, we investigated the antibacterial activity of the synthesized nanoparticles against Gram-positive and Gram-negative strains. Notably, the nanoparticles exhibited substantial antibacterial efficacy, with MIC values of 2.5 mg/ml for Staphylococcus aureus and Escherichia coli strains, respectively. This study highlights the multifaceted potential of ZnFe₂O₄@Au nanoparticles, making them a promising candidate for both environmental remediation and biological applications.