Synthesis of silver nanoparticles using wild Cucumis anguria: Characterization and antibacterial activity

In the present study silver nanoparticles were synthesized using wild Cucumis anguria leaf extract using the green route which is a simple, cost-effective and an environmentally friendly technique. When the aqueous silver ions were exposed to the wild C. anguria leaf extract, they were reduced and this resulted in the formation of silver nanoparticles. The conditions of synthesis were optimized by adjusting the pH, time and amount of leaf extract. The synthesized silver nanoparticles were characterized by different techniques, namely ultra-violet visible spectroscopy, Fourier Transform Infrared Spectroscopy, X-ray diffraction and transmission electron microscopy. The ultra violet-visible spectrum of the synthesized silver nanoparticles shows a maximum peak at 420 nm. Fourier transform infrared spectroscopy results show the presence of alcohols, aromatics and amines suggesting the presence and binding of proteins with silver nanoparticles. Transmission electron microscopy analysis shows that the silver nanoparticles synthesized were spherical in shape with their sizes ranging between 11 and 27 nm depending on the pH conditions. X-ray diffraction analysis results show the presence of silver metal nanoparticles and their crystalline nature. The antibacterial activity of the silver nanoparticles synthesized was evaluated against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacterial and kanamycin was used as a control. The green chemistry route has proven that silver nanoparticles can be synthesized using C. anguria leaf extract in which biomolecules effectively act as reducing and capping agents.    Key words: Silver nanoparticles, green synthesis, Cucumis anguria, antibacterial activity.