3 years ago

Gold decorated polystyrene particles for lateral flow immunodetection of Escherichia coli O157:H7

Lia A. Stanciu, Li-Kai Lin, Yoojung Heo, Amanda J. Deering, Jan P. Allebach, George T. -C. Chiu, Seon-Ah Jin


Conventional lateral flow immunoassays for pathogen detection usually make use of gold nanoparticles to impart the color necessary for a readout. Unfortunately, these immunoassays require an extra-long time enrichment process before the detection. The synthesis of gold-decorated polystyrene particles (Au-PS), and their incorporation in a lateral flow immunoassay (LFIA) with improved sensitivity for detection of the model pathogen Escherichia coli O157:H7 (E. coli O157:H7) were described in this article. The synthesis of the Au-PS particles occurred through the citrate reduction method. Then the particles underwent surface modification through coating with branched polyethylenimine, followed by grafting of the anti-E. coli O157:H7 antibody. The effect of Au-PS particle size and of the surface coverage on the detection limit of the assay was investigated. The Au-PS particles with 0.46 μm PS and 10% Au surface coverage achieved 500 CFU·mL−1 limit of detection (LOD) for E. coli O157:H7 in apple juice, ground beef, and spiked buffer solutions. Furthermore, these particles achieved 100 CFU·mL−1 LOD when the secondary a signal amplification reaction via gold reduction method was used. While the antibody-antigen interaction has a well-known role in detection, a precise optimization of the Au-PS particles used in LFIA assays can significantly affect performance. In our perception, Au nanoparticles coverage on sub-micron sized polystyrene particles was the critical factor that allowed reaching the reported low concentration of E. coli O157:H7 in real food samples. Graphical abstract

Microstructure of gold-decorated polystyrene (Au-PS) particles and a schematic illustration for the detection of Escherichia coli O157:H7 by a lateral flow immunoassay strip containing the same.

Publisher URL: https://link.springer.com/article/10.1007/s00604-017-2524-5

DOI: 10.1007/s00604-017-2524-5

You might also like
Never Miss Important Research

Researcher is an app designed by academics, for academics. Create a personalised feed in two minutes.
Choose from over 15,000 academics journals covering ten research areas then let Researcher deliver you papers tailored to your interests each day.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.