RETRACTED ARTICLE: Biosynthesis of colloidal silver nanoparticles: Their characterization and potential antibacterial activity

The colloidal silver nanoparticles (AgNPs) were synthesized in situ under white light at room temperature using aqueous silk fibroin (SF) obtained from Bombyxmori silk. The UV-visible spectroscopy revealed the formation of AgNPs by showing a typical surface Plasmon resonance (SPR) band at 422 nm from the UV-visible spectra. The transmission electron microscope (TEM) images show that the formed nanoparticles were spherical in shape with smooth surfaces. The particle diameter was around 35-40 nm. Further the X-ray diffraction (XRD) analysis confirms the nanocrystalline phase of silver with face centered cubic (FCC) crystal structure. The biogenic silver nanoparticles exhibited significant antibacterial activity against human bacterial pathogens Bacillus subtilis, Staphylococcus aureus, Salmonella typhi and Escherichia coli .