Jump to main content
Jump to site search


Highly sensitive colorimetric immunoassay for Escherichia coli O157:H7 based on probe of pseudo enzyme and signal dual amplification

Abstract

Here we developed a highly sensitive colorimetric immunoassay for the detection of Escherichia coli O157:H7 (E. coli O157:H7). The Fe3O4 nanoparticles coated carboxyl group were synthesized by a one-pot method and modified with E. coli O157:H7 antiserum as capture probes. Au@Pt nanoparticles with peroxidase-like activity were combined with flaky reduced graphene oxide-neutral red (rGO-NR) to form chromogenic probe of pseudo enzyme. To increase the sensitivity, BSA was replaced by horseradish peroxidase (HRP) as blocking protein of immune rGO-NR-Au@Pt. Meanwhile, HRP and Au@Pt constitute signal dual amplification system. In the presence of E. coli O157:H7, the capture probes and chromogenic probes formed sandwich structures. The complexes were used to catalytically oxidize the chromogenic substrate 3,3’,5,5’-tetramethylbenzidine (TMB) and the absorbance at 450 nm is relevant to the concentration of bacteria. Although the feasibility is demonstrated using E. coli O157:H7 as a model analyte, this approach can be easily developed to be a universal analysis system and applied to detection of a wide variety of foodborne pathogens and protein biomarkers. This study proposed a point-of-care (POC) and convenient quantitative detection method for the clinic diagnostics and food safety analysis.

Back to tab navigation

Publication details

The article was received on 26 Jun 2018, accepted on 04 Aug 2018 and first published on 06 Aug 2018


Article type: Paper
DOI: 10.1039/C8AY01410H
Citation: Anal. Methods, 2018, Accepted Manuscript
  •   Request permissions

    Highly sensitive colorimetric immunoassay for Escherichia coli O157:H7 based on probe of pseudo enzyme and signal dual amplification

    H. Huang, Z. Wu, J. Huang, G. Zhao and W. Dou, Anal. Methods, 2018, Accepted Manuscript , DOI: 10.1039/C8AY01410H

Search articles by author

Spotlight

Advertisements