Highly sensitive toxin microarray assay for aflatoxin B1 detection in cereals

- A toxin microarray developed for rapid and highly sensitive detection of AFB1.
- The toxin microarray successfully detected AFB1 wit detection limit of 1 pg g−1.
- Detection limits were 30 and 90 pg g−1 in spiked wheat and barley samples, respectively.
- Toxin assay procedure completed in 3 h time.

We report a rapid, highly sensitive microarray method for quantitative aflatoxin B1 (AFB1) detection in cereal samples. Following optimisation using an indirect competitive immunoassay, optimised amounts of AFB1-bovine serum albumin (AFB1-BSA)-conjugate were contact-printed onto 16 isolated sub-arrays on multi-pad nitrocellulose coated slides subsequently used in competitive binding assays.The toxin microarray working range for AFB1 was established in the range of 15 pg g−1 to 3.04 ng g−1, with a detection limit of 1 pg g−1. To determine assay sensitivity in contaminated food models, wheat flour and barley grains samples were spiked with AFB1 standard dilutions. Following extraction, the working ranges of 0.11-4.15 and 0.18-4.31 ng g−1 were determined, with detection limits of 30 and 90 pg g−1, respectively. The sensitivity of the developed assay is below the European commission limit set for AFB1 detection and the assay procedure was completed in 3 h time. Good recoveries (98% ± 11%) obtained demonstrate the suitability of the proposed method for rapid and sensitive quantification of AFB1 in contaminated cereal samples.