Green Synthesis of Metal Nanoparticles Using Plant Extracts: Comparison of Ag, ZnO and CuO Systems and Their Potential Biomedical Applications

Abstract

Green synthesis of metal nanoparticles using plant extracts represents a significant experimental challenge, as it requires careful optimization of reaction conditions such as pH, temperature, and the ratio of plant extract to metal precursors. Nevertheless, this approach offers an environmentally friendly and sustainable route for the production of nanomaterials with considerable application potential, particularly in the field of medicine. This paper presents a comparative analysis of the green synthesis of silver, zinc, and copper nanoparticles, with emphasis on differences in formation mechanisms, particle characteristics, stability, and potential applications. Special attention is given to their biomedical potential, which was systematically evaluated. The study is primarily based on the authors’ experimental results, including both published and unpublished data, supported by relevant literature. Nanoparticle formation was monitored by UV–Vis spectroscopy, while interactions between plant biomolecules and nanoparticle surfaces were examined using FTIR analysis. Particle morphology and size were determined by SEM and TEM techniques. The results indicate that silver nanoparticles are predominantly obtained in elemental form, whereas zinc and copper tend to form oxide nanoparticles (ZnO and CuO) due to their higher susceptibility to oxidation. Compared to ZnO and CuO, silver nanoparticles exhibit faster formation kinetics, narrower size distribution, and improved colloidal stability. Overall, all investigated nanoparticles demonstrate significant potential for biomedical applications.