Copper (Cu) nanoparticles are multifunctional in nature and have been used in many applications such as antimicrobial activity evaluation, photocatalysis, organic dye degradation, cosmetics and energy. It is important to develop clean, reliable and green methods of synthesis and characterization of Cu and its oxide nanoparticles for wide applications.
In this study, monodisperse Cu NPs were synthesized using a chemical reduction method without the use of harmful reducing agents. X-ray diffraction characterization showed that these particles consisted of metallic Cu and copper oxide. The X-ray spectrum also revealed the presence of carbon and oxygen peaks, indicating that these samples were stabilized with carbon materials.
The toxicity of these particles was evaluated in A549 lung carcinoma cells. The results showed that the NPs induced apoptosis in the cells by generating ROS which disturbs amino acid biosynthesis and DNA replication, whereas a lower toxicity was observed for ZnO-NPs due to their greater affinity for cellular membranes.
The morphological and internal composition of these NPs were also investigated using transmission electron microscopy and elemental analysis by energy-dispersive X-ray spectroscopy. These results demonstrated the feasibility of this method for biogenic synthesis of Cu and its oxide NPs with potential applications in electronic, magnetic, optical, catalytic and biological fields. The characterization of these NPs with different techniques helps to better understand their characteristics and potential future applications in the fields of catalysis, organic transformation, biomedicine, pharmaceutical, cosmetics and energy. Moreover, it is worth mentioning that this biogenic method allows to avoid the transformation of Cu into copper oxide during the synthesis process and consequently reduces the environmental impact.