A competitive immunoassay for zearalenone with integrated poly(dimethysiloxane) based microarray assay
A monoclonal antibody (mAb) (2B10) against zearalenone (ZEN) was prepared for the first time in this study. The mAb was class specific and showed no cross reactivity to other groups of mycotoxins. A competitive microarray assay based on a novel solid supporting material, an integrated poly(dimethylsiloxane) (iPDMS), is proposed for qualitative and/or semiquantitative determination of ZEN in cereal samples. The limit of detection (LOD) and limit of quantification (LOQ) of the iPDMS based method were 0.53 μg kg−1 and 1.02 μg kg−1 for ZEN, respectively, which was lower than the EU maximum limit (ML). Furthermore, recoveries ranged from 93% to 114% and the coefficients of variation were below 15%. The developed method was successfully applied to analyse 29 cereal samples and the results showed that three corn flour samples were ZEN positive, and two corn flour samples were determined to be suspicious, which was in a good agreement with the results obtained using LC-MS/MS. It is worth noting that, compared with ELISA, the developed microarray assay is rapid, simple and does not require a blocking step. In addition, owing to its advantage of zero background, appropriately increasing the concentration of coating antigen and horseradish peroxidase (HRP)-labeled secondary antibody can enhance the sensitivity of the membrane and reduce the matrix effects of the sample.