Indexed on: 19 Jul '16Published on: 19 Jul '16Published in: Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment
A sensitive immunochromatographic assay (ICA) using colloidal gold-antibody probe for rapid detection of fumonisin B1 (FB1) in corn samples was developed. The color density of the test line correlated with the concentration of FB1 in the range of 2-40 ng/mL by the assay, and the detection limit for FB1 was 2 ng/mL. The linear range for FB1 was 50-1000 µg/kg, and the visual limit detection of the test was 1000 µg/kg in corn samples. The immunochromatographic assay to detect FB1 is sensitive, specific and rapid. Specific anti-FB1 monoclonal antibody（mAb）and FB1-Ovalbumin (FB1-OVA) conjugate antigen were prepared. FB1 mAb, labeled with colloidal gold, was used as probes on the immunochromatographic strip. FB1-OVA and goat-anti-mouse IgG were coated onto nitrocellulose (NC) membrane as test lines and control lines, respectively. FB1 in samples will competitively combines the FB1 mAb with the FB1-OVA in an NC membrane and the results are directly observed by the color of the detection and quality control lines．In this study, the concentrations of FB1 mAb labeled with colloidal gold, detecting antigen and goat anti-mouse IgG were optimized. The results indicated that the test strip is specific for FB1, with no cross-reactivity to other toxins. The strip assay for FB1 was simple, only needing one step without complicated assay performance and expensive equipment, and the total time for visual evaluation was less than 10 min．A survey of 24 corn samples from Hefei, China, was performed with the test strip and HPLC, and the detection results showed that the developed ICA and the HPLC were in excellent agreement. Hence, the developed ICA can be used as a method for rapid detection of FB1 in corn samples．.