Aflatoxin B(1) antibody (aAFB(1)) covalently attached to cysteamine functionalized-gold nanoparticles (C-AuNP) has been immobilized onto 4-mercaptobenzoic acid (MBA) based self assembled monolayer (SAM) on gold electrode (MBA/Au), for the fabrication of BSA/aAFB(1)-C-AuNP/MBA/Au immunoelectrode. This immunoelectrode has been characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and electrochemical characterization techniques. The electrochemical response studies reveal that the BSA/aAFB(1)-C-AuNP/MBA/Au immunoelectrode can be used to detect AFBI in the range of 10-100 ng dL(-1) and has sensitivity as 0.45 mu A ng(-1)dL, limit of detection as 17.90 ng dL(-1) and a response time of 60 s. (C) 2010 Elsevier B.V. All rights reserved.