Highly sensitive simultaneous detection of major ochratoxins by an immunochromatographic assay

- An immunochromatographic assay was first developed for highly sensitive on-site detection of three major ochratoxins.
- The sensitivity of the developed ICA for OTA was the highest compared with those reported previously.
- The high sensitivity was obtained based on the high-affinity antibody instead of the complex enhancement strategy.

Ochratoxins are highly toxic contaminants and considerable threat to the health of humans and animals. Ochratoxins, mainly include ochratoxin A (OTA), ochratoxin B (OTB) and ochratoxin C (OTC), always exist in the food raw materials with the form of the mixture and they can convert to each other easily under special environment. The co-occurrence of three ochratoxins and conversion between different types of major ochratoxins make the specific detection for a separate kind of ochratoxin can not fully meet the rapid analysis demand of ochratoxins. Thus, the simultaneous detection for three major ochratoxins is urgent and indispensable. Here, a monoclonal antibody (mAb) which could simultaneously recognize OTA, OTB and OTC was screened out and then based on the mAb, an immunochromatographic assay (ICA) for rapid detection of the three major ochratoxins was first developed. After optimization, the visible limits of detection (vLODs) were 0.05, 0.025, 0.1 ng/mL and the cut-off concentrations were 0.5, 0.25, 0.5 ng/mL for OTA, OTB and OTC, respectively. Finally, the assay was evaluated using ochratoxins spiked maize samples, and results showed that the developed ICA could provide a practical method for the detection of three major ochratoxins on-site.