Simultaneous screening for T-2/HT-2 and deoxynivalenol in cereals using a surface plasmon resonance immunoassay

This manuscript describes a rapid surface plasmon resonance (SPR) immunoassay for the simultaneous determination of the sum of T-2/HT-2 toxins (T-2/HT-2) and deoxynivalenol (DON), in cereals and cereal-based products. The assay is based on an inhibition format employing a monoclonal antibody raised against HT-2 with cross reactivity to T-2 and a polyclonal antibody raised against DON, thereby enabling the detection of the three trichothecene mycotoxins (types A and B). The surface chemistry involved an equal mixture of HT-2 and DON covalently coupled onto a high capacity COOH5 sensor chip. Using the specified antibodies and a mixed toxin sensor surface, and running calibration curves (HT-2 and DON) and samples in parallel it has been proven that it is feasible to develop a multiplex assay on this SPR platform. In-house validation has shown limits of detection of 12, 1 and 29 μg/kg for DON and 31, 47 and 36 μg/kg for HT-2 in wheat, breakfast cereal and maize-based baby food, respectively. Both intra-assay and inter-assay precision were calculated using fortified DON and HT-2 samples. Durum wheat, wheatbased breakfast cereal and maize-based baby food were spiked at various concentration levels and the coefficients of variation calculated ranged from 1.1% to 9.9% for DON and from 1.4% to 11.3% for HT-2. A high correlation was observed between the screening assay and confirmatory mass spectrometry.