Sensitive electrochemical detection of Salmonella with chitosan-gold nanoparticles composite film

Talanta. 2015 Aug 1:140:122-127. doi: 10.1016/j.talanta.2015.03.033. Epub 2015 Mar 26.

Abstract

An ultrasensitive electrochemical immunosensor for detection of Salmonella has been developed based on using high density gold nanoparticles (GNPs) well dispersed in chitosan hydrogel and modified glassy carbon electrode. The composite film has been oxidized in NaCl solution and used as a platform for the immobilization of capture antibody (Ab1) for biorecognition. After incubation in Salmonella suspension and horseradish peroxidase (HRP) conjugated secondary antibody (Ab2) solution, a sandwich electrochemical immunosensor has been constructed. The electrochemical signal was obtained and improved by comparing the composite film with chitosan film. The result has shown that the constructed sensor provides a wide linear range from 10 to 10(5) CFU/mL with a low detection limit of 5 CFU/mL (at the ratio of signal to noise, S/N=3:1). Furthermore, the proposed immunosensor has demonstrated good selectivity and reproducibility, which indicates its potential in the clinical diagnosis of Salmonella contaminations.

Keywords: Chitosan; Composite film; Electrochemical immunosensor; Gold nanoparticles; Salmonella.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biosensing Techniques / instrumentation
  • Chitosan / chemistry*
  • Electrochemical Techniques / instrumentation*
  • Equipment Design
  • Gold / chemistry*
  • Humans
  • Limit of Detection
  • Metal Nanoparticles / chemistry*
  • Metal Nanoparticles / ultrastructure
  • Milk / microbiology
  • Reproducibility of Results
  • Salmonella / isolation & purification*
  • Salmonella Infections / microbiology*
  • Water Microbiology

Substances

  • Gold
  • Chitosan