Biosynthesis of silver nanoparticles by Mentha spicata ethanolic leaves extract and investigation the antibacterial activity

This study included the biosynthesis of silver nanoparticles by Mentha spicata ethanolic leaves extract. The prepared nanoparticles were characterized by spectroscopically methods and atomic force microscope (AFM). UV-Visible spectrum demonstrated the presence of plasmon resonance of silver nanoparticles. Fourier Transform Infrared (FTIR) spectrum revealed the appearance and disappearance of some absorption bands firstly and shifting of other bands either to higher or lower frequencies secondly. X-ray diffraction (XRD) confirmed the reduction of silver nitrate to silver nanoparticles. AFM analysis illustrated that the prepared nanoparticles were spherical in shape with a diameter of 76.40 nm. The study of antibacterial activity showed that silver nanoparticles have efficient inhibitory activity against multidrug resistance bacteria causing urinary tract infection, at mg/ml concentration with the average inhibition zone diameter of 18, 18.67, 16.83, 16 and 19 mm for Staphylococcus aureus, Escherichia coli, Enterococus faecalis, Proteus mirabilis and Acinetobacter baumannii, respectively.