Eco-friendly synthesis of silver nanoparticles from macroalgae: optimization, characterization and antimicrobial activity

Abstract

The traditional physical and chemical methods used in the production of silver nanoparticles (AgNP) consist of complex, expensive, and environmentally harmful processes. To overcome these problems, researchers have turned to the AgNP production method called green synthesis or biosynthesis. This study aims to produce AgNPs by green synthesis from the extracts of Ulva lactuca and Halopteris scoparia and to determine their antibacterial and antifungal activities. In this context, the effects of some process parameters on nanoparticle size were examined statistically and the antimicrobial activities of AgNPs produced under optimum conditions against various pathogenic bacteria and fungi were determined. The smallest AgNPs synthesized from Ulva lactuca and Halopteris scoparia extracts were measured as 40.19 +/- 5.93 and 34.88 +/- 4.38 nm, respectively, under the conditions of pH of 11, AgNO3 ratio of 10%, and temperature of 55 degrees C. As for the antibacterial activity of AgNPs, the diameters of the inhibition zones formed against pathogenic bacteria were found as between 10 and 15 mm. As for the antifungal activity, a reduction between 15 and 21.33 mm was observed in pathogenic fungi growths. With this study, it was concluded that macroalgae can be easily used in the green synthesis of AgNPs with antibacterial and antifungal properties. Future research of green-synthesized AgNPs from macroalgae will be highly important for being used as an antibacterial and antifungal agent in fields such as medicine and cosmetics.