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The biosynthesis of silver nanoparticles (AgNPs) using an aqueous extract of an agroindustrial residue of the tequila industry [i.e. leaves of Agave tequilana Weber var. azul (AT)], and silver nitrate or silver acetate as precursor salts is reported. The presence of AgNPs was confirmed by color change, scanning electron microscopy, ultraviolet visible spectroscopy and X-ray diffraction. AgNPs were tested against clinically important bacteria. The effect of extract concentration and the reaction temperature was investigated. Results revealed that, the concentration of AgNPs increases as temperature and extract concentration increase. AgNPs were found to be mainly spherical shaped and showed antibacterial activity against Staphylococcus aureus , Escherichia coli and Pseudomonas aeruginosa . Results demonstrate the possibility of using a natural extract obtained from an abundant agroindustrial residue for the sustainable synthesis of AgNPs. [ABSTRACT FROM AUTHOR]

Plant extracts contain sources of antimicrobial and antioxidant compounds that have been used as a reducing and stabilizing agents for biosynthesis of nanoparticles (NPs). Some studies suggest that plant extracts incorporating directed NPs, such as Ag, enhanced antioxidant activity, this study suggests the opposite. Red cabbage extract with silver NPs (Ag NPs) was prepared to study and how silver ions (Ag+) and Ag NPs influence antioxidant activity of red cabbage anthocyanin. Synthesized Ag NPs were characterized by UV–vis spectra, scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX). We studied Ag NPs formation as a function of Ag+ and anthocyanin concentrations. Results show that Ag+ and Ag NPs decreased antioxidant activity of anthocyanin towards DPPH. [ABSTRACT FROM AUTHOR]

In the present study, silver nanoparticles (AgNPs) were synthesized by using aqueous leaves extract of Skimmia laureola at room temperature. The color change in reaction mixture (pale yellow to dark brown) was observed during synthesis process. Biosynthesized silver nanoparticles showed surface Plasmon resonance at around 460 nm. The spherical and hexagonal shapes and crystalline nature of silver nanoparticles were confirmed by SEM and XRD analysis. The bioactive chemicals constituent of leaf extract of S. laureola such as tritepenoid s , skimmidiol and coumarins, were mainly involved in the synthesis of silver nanoparticles. Furthermore, antibacterial potential of aqueous extract of S. laureola leaf and biosynthesized silver nanoparticles found to be potent agent against tested human pathogens and it is suitable nanomaterial for biomedical application. [ABSTRACT FROM AUTHOR]

In the recent decades, development of green nanotechnology is generating interest of researchers toward ecofriendly biosynthesis of nanoparticles, because of its incredible applications in all fields of science. In this study, to explore the novel approaches for the biosynthesis of silver nanoparticles, the seaweed Enteromorpha flexuosa (wulfen) J. Agardh extract was mixed with silver nitrate to synthesize silver nanoparticles. The reduced silver nanoparticles were characterized by UV–vis spectrophotometer, energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The in vitro antimicrobial activity of the synthesized nanoparticles of E. flexuosa exhibited high antibacterial activity against Gram-positive bacteria and low activity against the Gram-negative organisms. The algae materials mediated synthesis of silver nanoparticles have comparatively rapid, less expensive and wide applications to antimicrobial therapy in modern medicine. [ABSTRACT FROM AUTHOR]