Electrochemical Immunosensor Based on Polythionine/Gold Nanoparticles for the Determination of Aflatoxin B1

Sensors

Joseph H.O. Owino¹  Omotayo A. Arotiba¹  Nicolette Hendricks¹  Everlyne A. Songa¹  Nazeem Jahed¹  Tesfaye T. Waryo¹  Rachel F. Ngece¹  Priscilla G.L. Baker¹ 

[1] id="af1-sensors-08-08262">SensorLab, Department of Chemistry, University of Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Afri

关键词: Immunosensor;    Gold nanoparticles;    Aflatoxin B₁;    Polythionine;    Horseradish peroxidise (HRP);   

DOI  :  10.3390/s8128262

来源: mdpi

【 摘 要 】

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 (ΔE_p) 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.

【 授权许可】

CC BY   
© 2008 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.