Green synthesis of silver, gold and silver/gold bimetallic nanoparticles using the Gloriosa superba leaf extract and their antibacterial and antibiofilm activities

Microb Pathog. 2016 Dec:101:1-11. doi: 10.1016/j.micpath.2016.10.011. Epub 2016 Oct 17.

Abstract

The green fabrication of metal nanoparticles using botanical extracts is gaining increasing research attention in nanotechnology, since it does not require high energy inputs or the production of highly toxic chemical byproducts. Here, silver (Ag), gold (Au) and their bimetallic (Ag/Au) nanoparticles (NPs) were green synthesized using the Gloriosa superba aqueous leaf extract. Metal NPs were studied by spectroscopic (UV-visible spectroscopy, fluorescence spectroscopy, FT-IR spectroscopy, XRD and EDX) and microscopic (AFM and TEM) analysis. AFM and TEM showed that Ag and Au NPs had triangular and spherical morphologies, with an average size of 20 nm. Bimetallic Ag/Au NPs showed spherical shapes with an average size of 10 nm. Ag and Ag/Au bimetallic NPs showed high antibacterial and antibiofilm activities towards Gram-positive and Gram-negative bacteria. Overall, the proposed synthesis route of Ag, Au and Ag/Au bimetallic NPs can be exploited by the pharmaceutical industry to develop drugs effective in the fight against microbic infections.

Keywords: Biofabrication; Biosafety; Gloriosa superba; Nanotechnology; Surface plasmon resonance.

MeSH terms

  • Anti-Bacterial Agents / metabolism*
  • Bacteria / drug effects
  • Biofilms / drug effects
  • Colchicaceae / chemistry*
  • Disk Diffusion Antimicrobial Tests
  • Gold / metabolism*
  • Green Chemistry Technology / methods*
  • Metal Nanoparticles / chemistry*
  • Metal Nanoparticles / ultrastructure
  • Microscopy, Atomic Force
  • Microscopy, Electron, Transmission
  • Plant Extracts / isolation & purification
  • Plant Extracts / metabolism*
  • Plant Leaves / chemistry
  • Silver / metabolism*
  • Spectrum Analysis

Substances

  • Anti-Bacterial Agents
  • Plant Extracts
  • Silver
  • Gold