Electrochemical immunosensor based on polythionine/gold nanoparticles for the determination of aflatoxin B1

  • Joseph H.O. Owino
  • , Omotayo A. Arotiba
  • , Nicolette Hendricks
  • , Everlyne A. Songa
  • , Nazeem Jahed
  • , Tesfaye T. Waryo
  • , Rachel F. Ngece
  • , Priscilla G.L. Baker
  • , Emmanuel I. Iwuoha

Research output: Contribution to journalArticlepeer-review

109 Citations (Scopus)

Abstract

An aflatoxin B1 (AFB1) electrochemical immunosensor was developed by the immobilisation of aflatoxin B1-bovine serum albumin (AFB1-BSA) conjugate on a polythionine (PTH)/gold nanoparticles (AuNP)-modified glassy carbon electrode (GCE). The surface of the AFB1-BSA conjugate was covered with horseradish peroxidase (HRP), in order to prevent non-specific binding of the immunosensors with ions in the test solution. The AFB1 immunosensor exhibited a quasi-reversible electrochemistry as indicated by a cyclic voltammetric (CV) peak separation (ΔEP) value of 62 mV. The experimental procedure for the detection of AFB1 involved the setting up of a competition between free AFB1 and the immobilised AFB1-BSA conjugate for the binding sites of free anti-aflatoxin B1 (anti-AFB1) antibody. The immunosensor's differential pulse voltammetry (DPV) responses (peak currents) decreased as the concentration of free AFB1 increased within a dynamic linear range (DLR) of 0.6 - 2.4 ng/mL AFB1 and a limit of detection (LOD) of 0.07 ng/mL AFB1. This immunosensing procedure eliminates the need for enzyme-labeled secondary antibodies normally used in conventional ELISA-based immunosensors.

Original languageEnglish
Pages (from-to)8262-8274
Number of pages13
JournalSensors
Volume8
Issue number12
DOIs
Publication statusPublished - Dec 2008
Externally publishedYes

Keywords

  • Aflatoxin B
  • Gold nanoparticles
  • Horseradish peroxidise (HRP)
  • Immunosensor
  • Polythionine

ASJC Scopus subject areas

  • Analytical Chemistry
  • Information Systems
  • Atomic and Molecular Physics, and Optics
  • Biochemistry
  • Instrumentation
  • Electrical and Electronic Engineering

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