Biosynthesis and Antimicrobial activities of Silver Nanoparticles (AgNPs) by using Leaf Extracts of Tagetes erecta (Marigold) and Tridax procumbens (Tridax)

Abstract

In the last few years, it has been seen that the importance of silver nanoparticles has gained much interest by many chemists and biologists. Therefore, Indian medicinal plants has yet to bring numerous sources of profitable, healthy, mostly reduced and stabilized compounds utilized in the biosynthesis of silver nanoparticle. The main aim of this study is to investigate the viable and sustainable ways for the biosynthesis of AgNPs from 1 mM aqueous AgNO3 using leaf extracts of two widely available plants such as Tagetes erecta (Marigold) and Tridax procumbens (Tridax), which are well known for their wide availability and medicinal property. AgNPs were synthesized by the reaction of 1 mM AgNO3 and 5% leaf extracts of each plant separately. The formations of the AgNPs were confirmed by the colour changes of the mixture solution and duly characterized by UV-Visible spectrophotometric analysis. Further, their antibacterial and antifungal activities were tested against two bacterial strains and one fungal strain. Finally, the AgNPs showing better antimicrobial activity was tested for their water disinfection study against three water samples collected from River, Pond and Cannel. Obtained AgNPs from the two different leaf extracts indicated higher antimicrobial activities against Escherichia coli and Bacillus spp. in comparison to both AgNO3 and the raw plant extracts of Marigold and Tridax. The final results showed that both Marigold and Tridax extract silver nanoparticles are showing significant antimicrobial activities, whereas Marigold has little more antimicrobial activity than Tridax. So the bacterial inhibition zone by the silver nanoparticles prepared from the marigold and Tridax leaves extract show maximum inhibition for Gram +ve S. aureus and K. Pnemoniae and Gram negative E. coli as well as A. niger. These synthesised AgNPs when applied for water disinfection, they became a bled to reduce more than 50% of the bacterial growth present in the water samples. At last the synthesized silver nanoparticles were discharged safely in the environment which can be utilized in the processes of pollution remediation.