Preparation, characterization, and antibacterial activity of γ-irradiated silver nanoparticles in aqueous gelatin

Colloidal silver nanoparticles （Ag-NPs） were obtained through γ-irradiation of aqueous solutions containing AgNO3 and gelatin as a silver source and stabilizer, respectively. The absorbed dose of γ-irradiation influences the particle diameter of the Ag-NPs, as evidenced from surface plasmon resonance （SPR） and transmission electron microscopy （TEM） images. When the γ-irradiation dose was increased （from 2 to 50 kGy）, the mean particle size was decreased continuously as a result of γ-induced Ag-NPs fragmentation. The antibacterial properties of the Ag-NPs were tested against Methicillinresistant Staphylococcus aureus （MRSA） （Gram-positive） and Pseudomonas aeruginosa （P.a） （Gram-negative） bacteria. This approach reveals that the γ-irradiation-mediated method is a promising simple route for synthesizing highly stable Ag-NPs in aqueous solutions with good antibacterial properties for different applications.

Plant-based synthesis of NiO nanoparticles using salvia macrosiphon Boiss extract and examination of their water treatment

The goal of this study was to synthesize nickel oxide nanoparticles(NiO-NPs)by the sol-gel method,which involved the use of salvia macrosiphon Boiss plant extract,Ni(NO3)2·6 H2 O as a capping agent,and a nickel precursor,respectively.The synthesized NiO-NPs were characterized by Fourier transform infrared spectroscopy(FTIR),ultraviolet-visible(UV-Vis)spectrophotometer,X-ray diffraction(XRD),field electron scanning electron microscopy(FESEM)/energy-dispersive X-ray spectroscopy(EDX),thermo-gravimetric analysis/differential thermal analysis(TGA/DTA)and vibrating sample magnetometer(VSM)analyzes.Also,according to the results of UV-Vis,the gap band of nanoparticles was calculated to be in the range of about 2.9-3.9 eV.The photocatalytic activity of nanoparticles on methylene blue(MB)degradation was investigated and according to the results,about 80%MB was apparently degraded in the presence of NiO-NPs under UV-A light(11 W)after 5 h in pH^11.We have evaluated the cytotoxicity of NiO-NPs on the multiple tumor cells by materials method,and all the utilized concentrations were observed to cause non-toxic effects;therefore,it can be suggested that these samples have the potential of being employed in different fields of medicine.