Gold Coating of Silver Nanoplates for Enhanced Dispersion Stability and Efficient Antimicrobial Activity against Intracellular Bacteria

Langmuir. 2018 Sep 4;34(35):10413-10418. doi: 10.1021/acs.langmuir.8b00540. Epub 2018 Aug 23.


Silver nanoparticles have antibacterial activity. However, the nanoparticles are unstable and easily form aggregates, which decreases their antibacterial activity. To improve the dispersion stability of silver nanoparticles in aqueous media and to increase their effectiveness as antibacterial agents, we coated triangular plate-like silver nanoparticles (silver nanoplates, Ag NPLs) with one or two layers of gold atoms (Ag@Au1L NPLs and Ag@Au2L NPLs, respectively). These gold coatings improved the dispersion stability in aqueous media with high salt concentrations. Ag@Au1L NPLs showed stronger antibacterial activity on pathogenic bacteria than Ag NPLs and Ag@Au2L NPLs. Furthermore, the Ag@Au1L NPLs decreased the number of bacteria in RAW 264.7 cells. The Ag@Au1L NPLs displayed no cytotoxicity towards RAW 264.7 cells and could be used as antibacterial agents for intracellular bacterial infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Anti-Bacterial Agents / toxicity
  • Gold / chemistry*
  • Metal Nanoparticles / chemistry*
  • Metal Nanoparticles / toxicity
  • Mice
  • Microbial Sensitivity Tests
  • Particle Size
  • Pseudomonas aeruginosa / drug effects
  • RAW 264.7 Cells
  • Salmonella typhimurium / drug effects
  • Silver / chemistry*


  • Anti-Bacterial Agents
  • Silver
  • Gold