A rapid optical immunoassay for the screening of T-2 and HT-2 toxin in cereals and maize-based baby food.

ABSTRACT

A rapid surface plasmon resonance (SPR) screening assay has been developed for the combined detection of T-2 and HT-2 toxins in naturally contaminated cereals using a sensor chip coated with an HT-2 toxin derivative and a monoclonal antibody. The antibody raised against HT-2 displayed high cross-reactivity with T-2 toxin while there was no cross-reaction observed with other commonly occurring trichothecenes. A simple extraction procedure using 40% methanol was applied to baby food, breakfast cereal, and wheat samples prior to biosensor analysis. Limits of detection (LOD) for each matrix were determined as 25 microg kg(-1) for baby food and breakfast cereal and 26 microg kg(-1) for wheat. Intra-assay precision (n=6) was calculated for each matrix. The results were expressed as the relative standard deviation and determined as 2.8% (100 microg kg(-1)) and 1.8% (200 microg kg(-1)) in breakfast cereal, 4.6% (50 microg kg(-1)) and 3.6% (100 microg kg(-1)) in wheat and 0.97% (25 microg kg(-1)) and 6.3% (50 microg kg(-1)) in baby food. Between run precision (n=3) performed at the same levels yielded relative standard deviations of 6.7% and 3.9% for breakfast cereals, 3.3% and 1.6% for wheat and 6.8% and 0.08% for baby food, respectively.