Synthesis and bio-physical characterization of Silver nanoparticle and Ag-mesoporous MnO2 nanocomposite for anti-microbial and anti-cancer activity

Abstract

In the present study, a unique precursor source and plant extract have been developed for biogenic synthesis of silver nanoparticles (AgNPs) using different silver precursor solutions. Mesoporous-MnO2 nanocomposites (before doping AgNPs in meso-MnO2) were prepared using anon-ionic surfactant (Triton X-100) and the antibacterial activity of the prepared sample was analyzed against various bacterial pathogens. The plant leaf extract of Alternanthera bettzickiana was used as a reducing agent. A fast ultra-sonication-assisted process facilitated the incorporation of AgNPs on mesoporous MnOx. Different type of silver precursor has been used to prepare the biogenic AgNPs for the first time. Particle sizes of AgNPs were obtained below 5–10nm. Surface area, morphology, crystalline phase, and particle size of the synthesized nanoparticles were characterized by X-ray diffraction (XRD), Brunauer, Emmett, Teller (BET)/Barrett, Joyner, Halenda (BJH)method, Scanning Electron Microscopy (SEM), and high-resolution transmission electron microscopy (HR-TEM) techniques. The antibacterial activity of biogenic AgNPs and AgNPs@meso-MnO2 were tested against gram-positive (Staphylococcus aureus and Streptococcus mutans) and gram-negative (Salmonella typhi, Escherichia coli and Pseudomonas aeruginosa) bacteria using the well diffusion assay. All samples including biogenic AgNPs and AgNPs@meso-MnO2 showed effective inhibition zones against all pathogens and no activity was observed for control and bulk meso-MnO2. Preliminary studies related to the anti-cancer activity of the prepared AgNPs have also been studied and compared for different route prepared silver nanoparticles.