title: Activity study of biogenic spherical silver nanoparticles towards microbes and oxidants.
abstract: The eco-friendly approach for the green synthesis of silver nanoparticles (SNP) using Terminalia bellirica (T. bellirica) fruit extract is reported herein. Initially formation of SNP was noticed through visual color change from yellow to reddish brown and further analyzed by surface plasmonic resonance (SPR) band at 429 nm using UV-Vis spectroscopy. Identification of different polyphenols present in T. bellirica extract was done using High Pressure Liquid Chromatography (HPLC). Aqueous T. bellirica extract contains high amount of gallic acid which is major secondary metabolite responsible for the reduction and stabilization process. It was established by analyses of extracts before and after reduction using HPLC. Formation of spherical SNP was characterized by Transmission Electron Microscopy (TEM) analysis. X-ray Diffraction (XRD) study revealed crystalline nature of SNP. Presence of different functional groups on the surface of SNP was evidenced by Fourier Transform Infrared Spectroscopy (FTIR) study. A plausible mechanism of reduction and stabilization processes involved in the synthesis of stable SNP was also explained based on HPLC and FTIR data. In addition, the synthesized SNP was tested for antibacterial and antioxidant activities. SNP showed good antimicrobial activity against both gram positive (S. aureus) and gram negative (E. coli) bacteria. It also showed good antioxidant activity compared to ascorbic acid as standard antioxidant by using standard DPPH method.
authors.affiliation: Trace Elements Speciation Research Laboratory, Environmental and Analytical Chemistry Division, School of Advanced Sciences, VIT University, Vellore 632014, India.
authors.forename: Kiran Kumar
authors.initials: KK
authors.lastname: Hoskote Anand
authors.affiliation: Trace Elements Speciation Research Laboratory, Environmental and Analytical Chemistry Division, School of Advanced Sciences, VIT University, Vellore 632014, India.
authors.forename: Badal Kumar
authors.initials: BK
authors.lastname: Mandal
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000187:drug effects*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D016877:Oxidants / Q000494:pharmacology*; D012834:Silver / Q000494:pharmacology*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013211:Staphylococcus aureus / Q000187:drug effects*; D029766:Terminalia / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D016877:Oxidants; D012834:Silver
keywords: DPPH; Secondary metabolites; Silver nanoparticles; Spherical; Terminalia bellirica