Augmented antimicrobial, antioxidant and catalytic activities of green synthesised silver nanoparticles

作者：Vijayan Remya; Joseph Siby; Mathew Beena^*

来源：Materials Research Express, 2018, 5(8): 085022.

DOI：10.1088/2053-1591/aaaf33;085022

• green synthesis
• silver nanoparticles
• microwave
• antimicrobial
• antioxidant
• catalysis

The eco-friendly synthesis of nanoparticles is an innovative step in the field of nanotechnology. Herein, we report a microwave assisted synthesis of silver nanoparticles using the leaf extract of a medicinal plant, Orthosiphon aristatus as both reducing and capping agent. Formation of orange colour with surface plasmon resonance peak at 436 nm in absorption spectrum confirms the formation of silver nanoparticles. Crystalline nature of the nanoparticles with face centred cubic geometry was confirmed from XRD and SAED patterns. TEM analysis showed that nanoparticles are spherical in shape and the size varies from 15-45 nm with average size 28.36 nm. The antimicrobial activities of synthesised nanoparticles were measured by agar well diffusion method against both bacterial and fungal strains. The bacterial strains used were Bacillus subtilis, Streptococcus sp, Enterobacter aerogenes and Pseudomonas sp. The fungal strains used were Penicillium citrinum and Aspergillus flavus. The nanoparticles show dose dependent increase in the zone of inhibition. DPPH assay was demonstrated that synthesised nanoparticles possess strong antioxidant activities. The catalytic activities of synthesised nanoparticles were examined by using them in the reduction reaction of nitro compounds like nitrophenol and nitroanilines with excess sodium borohydride. The nanoparticles show excellent catalytic activities and follow pseudo first order kinetics.

• 出版日期2018-8