Green synthesis of silver nano-particles, their characterization and antimicrobial activity

Biologically synthesized silver nanoparticles (SNPs) are being widely used in the field of medicine. Extracellular biosynthesis of silver nanoparticles was carried out by using locally available plant extracts for the reduction of aqueous silver ions in short period. The silver nanoparticles formation was confirmed by the colour change of plant extracts (SNPs) and further confirmed with the help of UV-VIS spectroscopy. The nanoparticles formed from the plant extract of Datura, Curry Leaves and ginger were found to be the most acceptable for further analysis. These phytosynthesized silver nanoparticles were tested for antibacterial and antifungal activities using disc diffusion method. The test cultures, Proteus, Pseudomonas, Klebsiella, Bacillus and E. coli species of bacteria and Aspergillus, Fusarium, Curvularia and Rhizopus species of fungal were used. The microbial property of silver nanoparticles was analyzed by measuring the inhibition zone. The silver nanoparticles were synthesized from the leaves of Datura metel, Murraya koenigi and Zingiber officinale. The SNPs synthesized from bark extracts of Datura metel and Murraya koenigi were toxic towards Klebsiella and Aspergillus and Pseudomonas and Fusarium sp. respectively. Whereas, the growth of Pseudomonas and Rhizopus sp. were inhibited by the SNPs synthesized from leaf extract of Zingiber officinale. The results indicated that the silver nanoparticles may have an important advantage over conventional antibiotics