Multimycotoxin dipstick enzyme immunoassay applied to wheat

A membrane‐based visual dipstick enzyme immunoassay for the simultaneous detection of up to five mycotoxins was developed. Multiple dots of the respective antibodies against aflatoxin B1 (AFB1), T‐2 toxin (T‐2), 3‐acetyldeoxynivalenol (3‐AcDON), roridin A (RA), and zearalenone (ZEA) were applied onto a dipstick membrane. The competitive immunoreactions were performed by incubation of the dipstick in a test tube containing sample solution and a mixture of the respective toxin‐horseradish peroxidase conjugates. After a second incubation in enzyme substrate/chromogen solution, a complete suppression of the (blue) colour development of the respective dot was scored positive. Visual detection limits for AFB1, T‐2, 3‐AcDON, RA, and ZEA in buffer solution were 2 ng/ml, 5 ng/ml, 50 ng/ml, 30 ng/ml, and 5 ng/ml respectively. Using a simple extraction procedure, the detection limits of the multimycotoxin assay in artificially contaminated wheat samples were 30 ng/g, 100 ng/g, 600 ng/g, 500 ng/g, and 60 ng/g, respec...