Background: Currently, the development of environmentally friendly methods in the synthesis of nanoparticles and the non-use of toxic substances in traditional methods is increasing. Biological processes for the synthesis of nanoparticles using microorganisms, enzymes, plants, and algae have been proposed as acceptable and environmentally friendly alternatives to chemical and physical methods, as these methods are associated with high risks and costs. Zinc oxide (ZnO), an important semiconductor nanoparticle, has attracted much attention due to its wide range of applications, such as electronics, optics, optoelectronics, and biomedicine. Although various biological methods have been reported for the synthesis of zinc oxide nanoparticles, the development of green and environmentally friendly methods for their synthesis seems necessary. This issue is important from the point of view that the microorganism extract used in the synthesis of nanoparticles will have a significant effect on their morphology and size, factors that influence the properties of nanoparticles.
Aim: Green synthesis of zinc oxide nanoparticles using sargassum brown algae extract and investigation of their antioxidant and cytotoxic properties.
Methodology: In this study, algae were collected from the tidal zone of the coast of the Persian Gulf. Brown algae was selected based on the dominant species available in the region. The type of brown algae in the region includes Sargassum. After washing the algae and removing its impurities, a certain volume of the extract was mixed with zinc acetate precursor. At the end, after filtering the contents of the reaction vessel and placing the remaining solid on filter paper in the oven, a white zinc oxide powder was obtained.
Findings: Zinc oxide nanoparticles were synthesized with the help of sargassum brown algae extract with a hexagonal wurtzite crystal structure and an average size of 35 nm. Synthesized nanoparticles showed antioxidant properties in DPPH te