Title : Comparative study of antimicrobial activity of various silver nanoparticles synthesized by various green methods
In recent years, silver nanoparticles (AgNPs) have drawn a great attention globally because of their unique characteristics making them used in a wide of applications in many fields. Lately, researchers have focused on the green synthesis of AgNPs. This type of synthesis is considered as an ecofriendly, low cost, and effective method for preparing nanoparticles; in contrast to chemical reduction methods that depend on using reducing agents which are not environmentally safe. In the present work, aqueous extracts of several plants including green tea, Ghaf, sage, ginger, garlic and capsicum were successfully used for the synthesis of the silver nanoparticles by reducing Ag+ ions (from AgNO3) into nanoparticles. The active constituents of the plants such as polysaccharides, phenolics, terpenoids and flavonoids play an important role as naturally reducing agents. Additionally, these groups of naturally occurring compounds can be used as capping agents for the AgNPs. In this study, we concentrated on the synthesis of AgNPs and compared between different products of AgNPs from different plants in terms of size, zeta potential, and antimicrobial activity. Charge of AgNPs from different plants were characterized using zeta potential analyzer, while UV-Vis spectrophotometer, dynamic light scattering (DLS), and transmission electron microscopy (TEM) were used for size measurement and to study the relationship between absorbance spectra and particle size. Figure 1 shows TEM and DLS results of size analysis of AgNPs synthesized from green tea extract. Moreover, we tested the antimicrobial activity of the synthesized AgNPs products, and they revealed a good activity against gram positive and gram negative bacteria and antifungal activity.
Audience take away:
• Explain the difference between Chemical and Green ways for nanoparticles preparation and the advantages and disadvantages of each.
• Provide an eco-friendly ways to prepare nanoparticles to be used in many medical and pharmaceutical applications.
• Introduce ways of characterizations and functionalization of nanoparticles.