Interactions of Bacterial Lipopolysaccharides with Gold Nanorod Surfaces Investigated by Refractometric Sensing

Nardine S. Abadeer, Gergö Fülöp, Si Chen, Mikael Käll, Catherine J. Murphy

Research output: Contribution to journalArticle

Abstract

The interface between nanoparticles and bacterial surfaces is of great interest for applications in nanomedicine and food safety. Here, we demonstrate that interactions between gold nanorods and bacterial surface molecules are governed by the nanoparticle surface coating. Polymer-coated gold nanorod substrates are exposed to lipopolysaccharides extracted from Pseudomonas aeruginosa, Salmonella enterica and Escherichia coli, and attachment is monitored using localized surface plasmon resonance refractometric sensing. The number of lipopolysaccharide molecules attached per nanorod is calculated from the shift in the plasmon maximum, which results from the change in refractive index after analyte binding. Colloidal gold nanorods in water are also incubated with lipopolysaccharides to demonstrate the effect of lipopolysaccharide concentration on plasmon shift,potential, and association constant. Both gold nanorod surface charge and surface chemistry affect gold nanorod-lipopolysaccharide interactions. In general, anionic lipopolysaccharides was found to attach more effectively to cationic gold nanorods than to neutral or anionic gold nanorods. Some variation in lipopolysaccharide attachment is also observed between the three strains studied, demonstrating the potential complexity of bacteria-nanoparticle interactions.

Original languageEnglish (US)
Pages (from-to)24915-24925
Number of pages11
JournalACS Applied Materials and Interfaces
Volume7
Issue number44
DOIs
StatePublished - Nov 11 2015

Keywords

  • bacteria-nanoparticle interactions
  • gold nanorods
  • lipopolysaccharides
  • localized surface plasmon resonance
  • refractometric sensing

ASJC Scopus subject areas

  • Materials Science(all)

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