Enhanced antibacterial activity of bimetallic gold-silver core-shell nanoparticles at low silver concentration

Herein we report the development of bimetallic Au@Ag core-shell nanoparticles (NPs) where gold nanoparticles (Au NPs) served as the seeds for continuous deposition of silver atoms on its surface. The core-shell structure and morphology were examined by UV-Vis spectroscopy, transmission electron micr...

Full description

Saved in:
Bibliographic Details
Published in:Nanoscale 2011-01, Vol.3 (12), p.5120-5125
Main Authors: Banerjee, Madhuchanda, Sharma, Shilpa, Chattopadhyay, Arun, Ghosh, Siddhartha Sankar
Format: Article
Language:English
Subjects:
Anti-Bacterial Agents - chemistry
Anti-Bacterial Agents - pharmacology
Bacteria - growth & development
Bacteria - ultrastructure
Cell Membrane - metabolism
Cell Membrane - ultrastructure
Enterococcus faecalis
Escherichia coli
Gold - chemistry
Gold - pharmacology
Metal Nanoparticles - chemistry
Metal Nanoparticles - ultrastructure
Pediococcus acidilactici
Pseudomonas aeruginosa
Silver - chemistry
Silver - pharmacology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Herein we report the development of bimetallic Au@Ag core-shell nanoparticles (NPs) where gold nanoparticles (Au NPs) served as the seeds for continuous deposition of silver atoms on its surface. The core-shell structure and morphology were examined by UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD). The core-shell NPs showed antibacterial activity against both gram negative (Escherichia coli and Pseudomonas aeruginosa) and gram positive (Enterococcus faecalis and Pediococcus acidilactici) bacteria at low concentration of silver present in the shell, with more efficacy against gram negative bacteria. TEM and flow cytometric studies showed that the core-shell NPs attached to the bacterial surface and caused membrane damage leading to cell death. The enhanced antibacterial properties of Au@Ag core-shell NPs was possibly due to the more active silver atoms in the shell surrounding gold core due to high surface free energy of the surface Ag atoms owing to shell thinness in the bimetallic NP structure.
ISSN:2040-3364
2040-3372
DOI:10.1039/c1nr10703h