Cashew-gum-based silver nanoparticles and palygorskite as green nanocomposites for antibacterial applications

Mater Sci Eng C Mater Biol Appl. 2020 Oct:115:110927. doi: 10.1016/j.msec.2020.110927. Epub 2020 Apr 3.

Abstract

Nanocomposite materials have been proposed to enhance the properties of different materials. In this study, palygorskite (Pal) clay is proposed as a support matrix for silver nanoparticles stabilised with cashew gum (Anacardium occidentale L.) (AgNPs-CG), producing the Pal/AgNPs-CG nanocomposite, whose bactericidal activity was studied. AgNPs-CG was synthesised using a green method in which CG acted as a reducing and stabilising agent for these nanostructures. AgNPs-CGs were subsequently characterised then adsorbed to the Pal surface, which was previously treated to remove impurities such as quartz. Pal and Pal/AgNPs-CG were characterised by X-ray diffraction, specific surface area, thermal analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, and transmission electron microscopy. The antibacterial activity assay by the direct contact method showed that the synergistic effect of the combination of AgNPs-CG and Pal increased the bactericidal effect of the nanomaterial compared with the AgNPs-CG activity, reaching a percentage inhibition of up to 70.2% against E. coli and 85.3% against S. aureus. Nanocomposite atoxicity was demonstrated by the Artemia Salina model. Thus, the Pal/AgNPs-CG nanocomposite emerges as a nanomaterial with potential antibacterial applications.

Keywords: Antibacterial agent; Biopolymer; Clay minerals; Green synthesis; Nanocomposite.

MeSH terms

  • Anacardium / chemistry*
  • Anti-Bacterial Agents
  • Escherichia coli / drug effects
  • Green Chemistry Technology
  • Magnesium Compounds / chemistry*
  • Metal Nanoparticles / chemistry
  • Microbial Sensitivity Tests
  • Microscopy, Electron, Scanning
  • Microscopy, Electron, Transmission
  • Nanocomposites / chemistry
  • Plant Gums / chemistry*
  • Silicon Compounds / chemistry*
  • Silver / chemistry
  • Silver / pharmacology*
  • Spectrometry, X-Ray Emission
  • Spectroscopy, Fourier Transform Infrared
  • Staphylococcus aureus / drug effects
  • X-Ray Diffraction

Substances

  • Anti-Bacterial Agents
  • Magnesium Compounds
  • Plant Gums
  • Silicon Compounds
  • Silver
  • attapulgite