Synthesis of stable colloidal silver nanoparticles with antibacterial properties by using Taxus baccata extract

Bacterial resistance to antibiotics increased the importance of developing novel antibacterial agents. Silver nanoparticles could be considered as one of the most important antibacterial agents. Regarding to the environmental concerns of widespread application of silver nanoparticles, the use of green methods for synthesis of the nanoparticles can lead to less concerns and to develop the nanoparticles with improved properties.
The ethanolic extract of Taxus baccata leaves was prepared and used in different concentrations for reduction of silver nitrate and synthesis of silver nanoparticles. The resulted nanoparticles were characterized by different methods including UV-Vis spectroscopy, Transmission electron microscopy, FT-IR, DLS, and Zetasizer. The antibacterial activity of silver nanoparticles was finally investigated using disk diffusion assay and minimum inhibitory concentration assay.
The ethanolic extract of T. baccata displayed high potential to synthesize high quality and stable silver nanoparticles with size below 50 nm. The nanoparticles displayed considerable antibacterial effect on all three tested bacteria. Minimum inhibitory concentration of 50 µg/ml obtained for S. pyogenes (ATCC 1447) and 25 µg/ml for E. coli (ATCC 25922) and S. aureus (ATCC 25923).
Discussion and The use of biological compounds especially plant extracts instead of dangerous and toxic chemicals for synthesis of silver nanoparticles could be considered as alternatives to reduce the environmental concerns of these nanoparticles. With respect to the considerable antibacterial activity of the nanoparticles synthesized with the present method, the nanoparticles can be used for different medical, food, and industrial applications.