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.