Green Synthesis of Silver Nanoparticles from Aqueous Leaf Extract of Medinilla beddomei C B Clarke and its Antimicrobial Activity

Abstract

Silver nanoparticles were synthesized from aqueous leaf extract of Medinilla beddomei C B Clarke and evaluated its antimicrobial activity against different bacterial and fungal strains. Here silver nanoparticles were synthesized through green route using leaves of M. beddomei, confirmed by color change and UV-visible spectroscopy. The silver nanoparticles were characterized by transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) studies. The antimicrobial activity of the silver nanoparticles was evaluated by agar well diffusion method against four bacterial strains and two fungal strains. The formation of silver nanoparticles after treatment was confirmed by the colour change of the aqueous leaf extract into dark brown. TEM and XRD studies revealed that the synthesized silver nanoparticles are almost spherical, with an average size of 18.88 nm. The silver nanoparticles synthesized from M. beddomei showed high antimicrobial activity for 50 and 100 μg/mL concentrations. The highest antimicrobial activity was found against Aspergillus niger. The zone of inhibition of fungal strain shown by A. niger (36.00 ± 1.50 mm) at 100 μg/mL was higher than that of ciprofloxacin (28.00 ± 1.57 mm) at 200 mg/mL, the positive control. The silver nanoparticles synthesized from the aqueous leaf extract of M. beddomei possess high antimicrobial efficacy against pathogenic bacterial and fungal strains. It can be exploited well in the pharmaceutical industry and for nanomedicine also.