Development of a visual immunosensing platform based on fluorescent microspheres for the rapid detection of ochratoxins in cereals.

Ochratoxins (OTs, including OTA, OTB, and OTC), exhibit nephrotoxicity, carcinogenicity, teratogenicity, and immunotoxicity, contaminating wheat, maize, and rice, so endangering human health. In this study, we designed and screened haptens using computational chemistry to prepare mAb 4G11, which simultaneously recognized OTA, OTB, and OTC with high sensitivity and specificity. We developed a fluorescent microsphere immunochromatographic assay (FMIA), which could detect the total amount of OTs with a visual detection limit of 0.5 ng/mL and a quantification limit of 0.27 ng/mL. Recovery experiments ranged from 95.94 % to 106.01 % with coefficients of variation ranging from 2.74 % to 6.30 %. The results obtained from the FMIA were found to be in alignment with those obtained from liquid chromatography-tandem mass spectrometry. The FMIA reliability was further demonstrated using real samples. FMIA can serve as a valuable instrument for the surveillance of the content of OTs in cereals.