An ultrasensitive chemiluminescence immunoassay for fumonisin B-1 detection in cereals based on gold-coated magnetic nanoparticles

BACKGROUNDIn the present study, a novel highly sensitive magnetic enzyme chemiluminescence immunoassay (MECLIA) was developed to detect fumonisin B-1 (FB1) in cereal samples. The gold-coated magnetic nanoparticles (Fe3O4@Au, GoldMag) were used as solid phase carrier to develop a competitive CLIA for detecting FB1, in which FB1 in samples would compete with FB1-ovalbumin coated on the surface of Fe3O4@Au nanoparticles for binding with FB1 antibodies. Successively, horseradish peroxidase labeled goat anti-rabbit IgG (HRP-IgG) was conjugated with FB1 antibodies on the microplate. In substrate solution containing luminol and H2O2, HRP-IgG catalyzed luminol oxidation by H2O2, generating a high chemiluminescence signal. The FB1 immune GoldMag particles were characterized by Fourier transform infrared spectroscopy, scanning electron microscope and zeta potential analysis, etc. RESULTSThe concentrations and the reaction times of these immunoreagents were optimized to improve the performances of this method. The established method could detect as low as 0.027ng mL(-1) FB1 from 0.05ng mL(-1) to 25ng mL(-1), demonstrating little cross-reaction (less than 2.4%) with other structurally related compounds. The average intrassay relative SD (RSD) (n=6) was 3.4% and the average interassay RSD (n=6) was 5.4%. This method was successfully applied for the determination of FB1 in corn and wheat and gave recoveries of between 98-110% and 91-105%, respectively. CONCLUSIONThe results of the present study suggest that the MECLIA approach has potential application for high-throughput fumonisin screening in cereals. (c) 2018 Society of Chemical Industry