Green Synthesis of Cu-Zn Bimetallic Nanoparticles via Trifolium alexandrinum Extract: Structural Characterization, Biochemical Potential and Photocatalytic Application

The goal of this study was to synthesize the bimetallic nanoparticles using leaf extract of Trifolium alexandrinum, copper sulphate and zinc sulphate and screening their biological and photocatalytic activities. Since growing antibiotic resistance is a significant problem, metallic nanoparticles, which are well-known for their wide biological spectrum, are proving to be an efficient substitute for currently available antibiotics. Leaf extract of T. alexandrinum (TFL) and its bimetallic Cu-Zn (CZS) nanoparticles have been synthesized. Fourier transform infrared spectroscopy, ultraviolet spectroscopy, transmission electron microscopy, field emission scanning electron microscopy, X-ray diffraction and energy dispersive X-ray were used to analyze and characterize the synthesized nanoparticles. The Fourier transform infrared spectroscopy describes the presence of different functional groups in the leaf extract as well as changes in their nature after combining with metal salts. Field emission scanning electron microscopy reveals the formation of nanoparticles in agglomerated form with spherical shape. Transmission electron microscopy images also coincide with the results of scanning electron microscopy. The X-ray diffraction pattern confirms the formation of crystalline nanoparticles with 77% crystallinity with an average size of about 50-150 nm, whereas EDX certifies the presence of different constituent abundances in the form of percentage. Further, the biological potential of the obtained nanoparticles was estimated by evaluating the antimicrobial and anti-angiogenic activities. The maximum value for bacterial inhibition was found to be 21.5 mm and for fungal inhibition this value reaches to 20 mm for 100 µL each. The percentage inhibition on vessel growth rate in TFL/CZS nanoparticle treated groups was obtained as 28% (1 µg) and 85% (10 µg). Percentage degradation for the composite was attained 83%, which was much better than CZS nanoparticles towards the Congo red dye. Results have shown that subjected nanoparticles were proven as excellent biological agents. Moreover, the photocatalytic activity confirms that the novel bimetallic nanoparticles can be used to treat the wastewater at initial level.