Green Synthesis of Silver Nanoparticles Using Marine Brown Algae Sargassum

The present study was aimed to optimize the protocol for the synthesis of silver nanoparticles using aqueous extracts of Sargassum swartzii (Turner) C.Agardh and evaluate cytotoxic potetnials using brine shrimp bio-assay activity and Trypan blue dye exclusion method. The reduction of pure Ag+ ions was monitored by measuring the UV-Vis spectrum of the solution at 200-900 nm using Shimadzu spectrophotometer and the characteristic peaks were detected. FTIR analysis was performed using Perkin Elmer Spectrophotometer system, which was used to detect the characteristic peaks and their functional groups of Sargassum swartzii SNPs. To know the cytotoxic potentials, the brine shrimp bio-assay was performed. To reveal the anticancer potetnials of Sargassum swartzii SNPs Trypan blue dye exclusion method employed against DLA cell lines. On mixing the S. swartzii aqueous extract with 1mM AgNO3 solution, the colour of the solution changes from pale yellowish brown to dark brown colour indicates the presence of silver nanoparticles. The AgNP’s synthesized from aqueous extracts of S. swartzii showed the optical peak at 430 nm with the absorption of 1.080. The synthesized silver nanoparticles were capped by proteins and metabolites such as phenolic acid, carboxylic acid and flavonoids. The capping was confirmed by the existence of band at 1640.16 and 3370 cm–1. The silver nanoparticles synthesized from S. swartzii showed highest percentage mortality with lowest LC50 value with 495.92 μg/ml. In S. swartzii AgNPs, maximum frequency of cell inhibition observed at CTC50 value 213.88 μl/ml. It is confirmed that silver nanoparticles are capable of rendering high cytotoxic activity and hence has a great potential in the preparation of anti-cancer drugs. The green chemistry approach towards the synthesis of ecofriendly Ag-NPs may bring fruitful applications in pharmaceutica and electronics industries.