Semi-quantitative and quantitative detection of ochratoxin A in agricultural by-products using a self-assembling immunochromatographic strip.

Background: The toxicity and health risks of mycotoxins have encouraged increased awareness and strict monitoring of these contaminants in agricultural by-products. In this paper, we developed and tested a sensitive, selective, and self-assembling immunochromatographic (IC) strip for on-site detection of ochratoxin A (OTA). We were able to demonstrate semi-quantitative and quantitative detection of OTA in agricultural by-product samples.

Results: The optimized IC strip had a limit of detection (LOD) of 0.5 ng mL OTA using the naked eye for semi-quantitative detection. When a digitized strip reader was used to achieve quantitative results, the LOD for OTA was reduced to 0.1 ng mL with a linear detection range of 0.1-10 ng mL . We also evaluated the specificity, stability, accuracy, and precision of the IC strip and demonstrated high performance in all of these areas. We then confirmed the ability of the IC strip to visually detect OTA contamination in authentic agricultural by-product samples from the markets in China. Furthermore, quantitative detection of OTA using the IC strip showed that the concentration of OTA ranged from 1.7 to 101.3 ng g in the positive agricultural by-product samples, correlating well with the measurements obtained via liquid chromatography with tandem mass spectrometry.

Conclusion: The results indicated that this proposed IC strip was capable of sensitive, semi-quantitative, quantitative, and on-site detection of OTA contamination in agricultural by-product samples. © 2020 Society of Chemical Industry.