Green synthesis of Copper and Silver Nanostructured Particles from Eremurus Plant Extract and Comparison of their Optical Properties and Antibacterial Activities

In the present investigation, silver (Ag) and copper (Cu) nanostructured particles were synthesized from Eremurus plant by means of an environmentally benign methodology in which plant extracts served as both reducing and stabilizing agents. The resultant nanostructured particles were subjected to characterization techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FESEM), and energy-dispersive X-ray spectroscopy (EDXS). XRD analysis confirmed development of Ag nanostructured particles with face-centered cubic (fcc) structure and also Cu nanostructured particles with cubic form. Moreover, the average crystallite dimensions obtained for Ag and Cu were 18.3 nm and 65.7 nm, respectively. FESEM images disclosed spherical-shaped morphology of Ag alongside cubic form of Cu. The optical characteristics were scrutinized via UV-Visible spectroscopy, which revealed distinctive absorption peaks at 205 nm for Ag and 230 nm for Cu where Ag demonstrated a superior extinction coefficient, thereby indicated enhanced optical activity. The antibacterial performance of Ag and Cu nanostructured particles was assessed against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) employing the colony-forming unit (CFU) methodology. Ag nanostructured particles exhibited remarkable antibacterial efficacy, achieving a reduction exceeding 99.99999% against E. coli and over 99.999% against S. aureus at a concentration of 8 mg/mL. Cu nanostructured particles similarly manifested substantial antibacterial effects, diminishing E. coli populations by over 99.99999% and S. aureus by greater than 99.98% at a concentration of 0.3 mg/mL. The augmented antimicrobial properties of Ag and Cu nanostructured particles underscored their prospective applications in biomedical, environmental, and antimicrobial coating domains.