Green synthesis of Ag/Fe3O4 nanoparticles using Mentha longifolia flower extract: evaluation of its antioxidant and anti-lung cancer effects

Galactomannan polysaccharide as a biotemplate for the synthesis of zinc oxide nanoparticles with photocatalytic, antimicrobial and anticancer applications

Biotemplates provide a facile, rapid, and environmentally benign route for synthesizing various nanostructured materials. Herein, Locust Bean Gum (LBG), a galactomannan polysaccharide, has been used as a biotemplate for synthesizing ZnO nanoparticles (NPs) for the first time. The composition, structure, morphology, and bandgap of ZnO were investigated by Energy Dispersive X-ray Spectroscopy (EDX), X-Ray Photoelectron Spectroscopy (XPS), X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and UV-vis spectroscopy. XRD data showed single-phase crystalline hexagonal NPs. FTIR spectra confirmed the presence of M-O bonding in the sample. At a concentration of 0.5 mg/mL the NPs can degrade Rhodamine B under sunlight, displaying excellent photocatalytic activity. These NPs exhibited antimicrobial activity in both Staphylococcus aureus and Bacillus subtilis. Significant cell death was observed at 500 μg/mL, 250 μg/mL, 125 μg/mL and 62.5 μg/mL of NP in breast cancer, ovarian cancer and lung cancer cell lines. Wound healing assay showed that the NPs significantly blocked the cell migration at a concentration as low as 62.5 μg/mL in all three cell lines. Further optimization of the nanostructure properties will make it a promising candidate in the field of nano-biotechnology and bioengineering owing to its wide range of potential applications.

Green synthesis of magnetic silver nanocomposite: the photocatalytic performance of nanocomposite to decolorize organic dyes

The magnetite-silver nanocomposites (Fe3O4-Ag NCs) were synthesized via a facile and green process by Citrus sinensis peel extract. The deposition of silver nanoparticles (NPs) was confirmed by observing an absorption peak at the maximum wavelength at 422 nm in the suspension solution of samples, which is related to silver surface plasmon resonance (SPR). The characteristic diffraction patterns of Fe3O4 and Ag phases were characterized utilizing the XRD patterns and the average size of the crystals was 21 nm. The photocatalytic behavior of Fe3O4-Ag NCs was studied for the destruction of three organic dyes methyl green (MG), methyl orange (MO), and methylene blue (MB) below UV radiation. The effect of the amount of photocatalyst and volume of hydrogen peroxide as an oxidant in the process of dye degradation was also investigated. The complete degradation time of dyes MB, MG, and MO under UV irradiation in the presence of 0.002 g Fe3O4-Ag NCs were 57, 33, and 49 min, respectively. The time of degradation reactions showed the high photocatalytic performance of Fe3O4-Ag NCs. These results proved that the synergistic effect of magnetite in the role of supporting the silver NPs was a significant contribution to the excellent decolorization behavior of Fe3O4-Ag NCs.