Ultrasensitive nanogold probe-based immunochromatographic assay for simultaneous detection of total aflatoxins in peanuts.

An ultrasensitive immunochromatographic (IC) assay for simultaneous detection of total aflatoxins (AFB1, AFB2, AFG1, and AFG2) was developed to meet the requirement for rapidly monitoring aflatoxins in agro-products. The assay was based on a competitive format and its sensitivity was improved by using a novel criterion to screen the optimal amount of monoclonal antibody (MAb) labeled to nanogold particles. The visual detection limits (VDLs) for aflatoxins B1, B2, G1, and G2 in peanut matrix were 0.03, 0.06, 0.12, and 0.25 ng mL(-1), respectively, which were lower than those of published literatures. The results of IC assay were in good agreement with those of high performance liquid chromatography (HPLC) in the analysis of aflatoxins in peanuts, demonstrating the practical applicability of the developed assay in real samples. This qualitative test based on the visual evaluation of results did not require any equipment. Overall, to our knowledge, this is the first report of qualitative detection for total aflatoxins by immunochromatographic assay.