Green synthesis of Mesona Blumes gum capped silver nanoparticles and their antioxidant, antibacterial and catalytic studies

Economically viable and eco-friendly Mesona Blumes (M.B.) gum was employed to synthesize AgNPs. The synthesis parameters such as concentration of silver nitrate (AgNO3), M.B. gum, microwave irradiation time and pH effect were optimized using a UV-visible spectrophotometer. It was observed that increasing the concentration of silver nitrate (AgNO3), M.B. gum, and microwave irradiation time enhanced the formation of MB@AgNPs. Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and transmission electron microscopy (TEM) techniques were used to characterize the synthesized MB@AgNPs. The XRD results confirmed a face-centred cubic structure, whereas TEM analysis indicated spherical particles of size 10 nm +/- 2 nm. The majority of AgNPs were smooth and spherical, and very few were irregular. The catalytic efficacy of the MB@AgNPs was studied in the presence of NaBH4 for the reduction of crystal violet (CV) and rhodamine-B (Rh-B) dyes. Rh-B dye was reduced in 300 seconds, while CV dye was reduced in 280 seconds. The inhibition zones of Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Bacillus cereus for the MB@AgNPs were 14, 12, 15, and 11 mm, respectively. The DPPH radical scavenging ability of the AgNPs was assessed using a DPPH radical scavenging assay.