An eco-benign synthesis of silver nanoparticles using Aegle marmelos L. bark extract and evaluation of their DNA cleavage, DNA binding, antioxidant and antibacterial activity

The present study demonstrates green chemistry assisted synthesis of silver nanoparticles (B-AgNPs) in aqueous medium employing bark extract of Aegle marmelos L., their characterization and biological applications. B-AgNPs were synthesized at 70 degrees C with 0.005 M AgNO3 was reduced with 5.0 mL of bark extract for 20 min and monitored with UV-Vis spectrum. The size, charge, stability, and polydispersity index of B-AgNPs were determined using dynamic light scattering (DLS) and zeta potential analysis. Scanning electron microscope and high resolution transmission electron microscopy images showed that spherical-shaped BAgNPs were formed with average size of 20 nm along with a hydrodynamic diameter ranging from 5 to 100 nm in two subpopulations as evaluated by DLS analysis. Fourier transmission infrared spectrum ascertain the functional groups and purity while energy dispersive X-ray spectroscopy study confirms the elemental composition of BAgNP. B-AgNPs remarkably exhibit DNA cleavage activity against pUC19 and binding activity with CT-DNA. The growth inhibition potential of BAgNPs against Staphylococcus aureus, Escherichia Coli, and Pseudomonas aeruginosa bacterial strains was tested and they exhibited minimum inhibitory concentration value 10 mu M against E. coli lower than the plant extract. DPPH assay in different concentrations of BAgNPs revealed the antioxidant potential between 41.3% and 90.2%.