In silico studies and development of a protein-based electrochemical sensor for selective and sensitive detection of aflatoxin B1.

ABSTRACT

Proteins from different species have been docked with aflatoxin B1 (AFB1) and identified 3 proteins (prostaglandin-E(2)9-reductase from Oryctolagus uniculus, proto-oncogene serine/threonine-protein kinase Pim-1 and human immunoglobulin G (hIgG)) as potential candidates to develop an electrochemical sensor. Fluorescence spectroscopy experiments have confirmed the interaction of hIgG with AFB1 with an affinity constant of 4.6 × 105 M-1. As a proof-of-concept, hIgG was immobilized on carbon nanocomposite (carbon nanotube-nanofiber, CNT-F)-coated glassy carbon electrode (GCE). FT-IR spectra, HR-TEM and BCA assay have confirmed successful immobilization of hIgG on the electrode (hIgG@CNT-F/GCE). The preparation of this protein electrochemical sensor requires only 1 h 36 min, which is fast as compared with preparing an electro immunosensor. hIgG@CNT-F/GCE has displayed an excellent AFB1 limit of detection (0.1 ng/mL), commendable selectivity in the presence of two other mycotoxins (ochratoxin A and patulin) and the detection of  AFB1 in spiked peanuts and corn samples.