Green synthesis of silver nanoparticles from marigold flower and its synergistic antimicrobial potential

In the present study, silver nanoparticles were synthesized using flower broth of Tagetes erecta as reductant by a simple and eco-friendly route. The aqueous silver ions when exposed to flower broth were reduced and resulted in green synthesis of silver nanoparticles. The silver nanoparticles were characterized by UV–visible spectroscopy, zeta potential, Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction, Transmission electron microscopy (TEM) analysis, Energy dispersive X-ray analysis (EDX) and selected area electron diffraction (SAED) pattern. UV–visible spectrum of synthesized silver nanoparticles showed maximum peak at 430 nm. TEM analysis revealed that the particles were spherical, hexagonal and irregular in shape and size ranging from 10 to 90 nm and Energy dispersive X-ray (EDX) spectrum confirmed the presence of silver metal. Synergistic antimicrobial potential of silver nanoparticles was evaluated with various commercial antibiotics against Gram positive (Staphylococcus aureus and Bacillus cereus), Gram negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and fungi (Candida glabrata, Candida albicans, Cryptococcae neoformans). The antifungal activity of AgNPs with antibiotics was better than antibiotics alone against the tested fungal strains and Gram negative bacteria, thus signification of the present study is in production of biomedical products.