Sensitive enzyme-linked immunosorbent assay and rapid one-step immunochromatographic strip for fumonisin B1 in grain-based food and feed samples

BACKGROUND: Maize contaminated with mycotoxin fumonisin B1 poses a global threat to agricultural production. In this study, polyclonal antibodies (pAb) specific to fumonisin B1 were generated from rabbits immunised with fumonisin B1-keyhole limpet haemocyanin (KLH). These antibodies were used to establish a sensitive competitive direct enzyme-linked immunosorbent assay (cdELISA) and gold nanoparticle immunochromatographic strip for detecting fumonisin B1 levels in maize-based foods and feeds. RESULTS: In cdELISA, fumonisins B1, B2 and B3 at concentrations of 0.42, 0.58 and 81.5 ng mL(-1) respectively caused 50% inhibition (IC50) of binding of fumonisin B1-horseradish peroxidase (HRP) to the antibodies. Effective on-site detection of fumonisin B1 was achieved by developing a rapid and sensitive pAb-based gold nanoparticle immunochromatographic strip. This strip had a detection limit of 5 ng mL-1 for fumonisin B1 in maize-based samples. Additionally, the whole analytical process could be completed within 10 min. Close examination of 15 maize-based samples by cdELISA revealed that 11 were fumonisin-positive, with a mean concentration of 435 +/- 20.1 ng g(-1). These results correlated well with those obtained by immunochromatographic strip. CONCLUSION: Both cdELISA and immunochromatographic strip methods established in this study are sensitive for rapid detection of fumonisins in agricultural commodities. (C) 2010 Society of Chemical Industry