Owino, Joseph H.O.Arotiba, Omotayo A.Hendricks, NicoletteSonga, EverlyneJahed, NazeemWaryo, Tesfaye T.Ngece, Rachel F.Baker, PriscillaIwuoha, Emmanuel I.2016-12-212016-12-212008Owino, J.H.O. et al. (2008). Electrochemical immunosensor based on polythionine/gold nanoparticles for the determination of Aflatoxin B1. Sensors, 8(12), 8262-82741424-8220http://hdl.handle.net/10566/2475http://dx.doi.org/10.3390/s8128262An 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.enAll articles published by MDPI are made immediately available worldwide under an open access license.ImmunosensorGold nanoparticlesAflatoxin B1PolythionineHorseradish peroxidise (HRP)Article