Characterisation of biosynthesised silver nanoparticles by scanning electrochemical microscopy (SECM) and voltammetry

Talanta. 2015 Jan:132:294-300. doi: 10.1016/j.talanta.2014.09.023. Epub 2014 Sep 19.

Abstract

Silver nanoparticles (AgNPs) were biosynthesised by a Klebsiella oxytoca strain BAS-10, which, during its growth, is known to produce a branched exopolysaccharide (EPS). Klebsiella oxytoca cultures, treated with AgNO3 and grown under either aerobic or anaerobic conditions, produced silver nanoparticles embedded in EPS (AgNPs-EPS) containing different amounts of Ag(0) and Ag(I) forms. The average size of the AgNPs-EPS was determined by transmission electron microscopy, while the relative abundance of Ag(0)- or Ag(I)-containing AgNPs-EPS was established by scanning electrochemical microscopy (SECM). Moreover, the release of silver(I) species from the various types of AgNPs-EPS was investigated by combining SECM with anodic stripping voltammetry. These measurements allowed obtaining information on the kinetic of silver ions release from AgNPs-EPS and their concentration profiles at the substrate/water interface.

Keywords: Anodic stripping voltammetry; Bacteria; Biosynthesis; Scanning electrochemical microscopy; Silver nanoparticles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Transport
  • Electrochemical Techniques
  • Klebsiella oxytoca / chemistry
  • Klebsiella oxytoca / drug effects
  • Klebsiella oxytoca / growth & development
  • Klebsiella oxytoca / metabolism*
  • Metal Nanoparticles / chemistry*
  • Metal Nanoparticles / ultrastructure
  • Microscopy, Electrochemical, Scanning
  • Microscopy, Electron, Scanning
  • Particle Size
  • Polysaccharides, Bacterial / biosynthesis
  • Polysaccharides, Bacterial / chemistry*
  • Silver / chemistry*
  • Silver / metabolism
  • Silver Nitrate / chemistry*
  • Silver Nitrate / pharmacology

Substances

  • Polysaccharides, Bacterial
  • Silver
  • Silver Nitrate