An ultrasensitive chemiluminescence immunoassay for fumonisin B1 detection in cereals based on gold-coated magnetic nanoparticles.

BACKGROUND: In the present study, a novel highly sensitive magnetic enzyme chemiluminescence immunoassay (MECLIA) was developed to detect fumonisin B1 (FB1 ) in cereal samples. The gold-coated magnetic nanoparticles (Fe3 O4 @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 Fe3 O4 @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 H2 O2 , HRP-IgG catalyzed luminol oxidation by H2 O2 , 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. RESULTS: The 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 0.027 ng mL-1 FB1 from 0.05 ng mL-1 to 25 ng 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. CONCLUSION: The results of the present study suggest that the MECLIA approach has potential application for high-throughput fumonisin screening in cereals. © 2018 Society of Chemical Industry.