Establishment of a Chemiluminescence Immunoassay Combined with Immunomagnetic Beads for Rapid Analysis of Ochratoxin A.

Abstract

Ochratoxin A (OTA) is a harmful mycotoxin and secondary metabolite produced by several species of Aspergillus and Penicillium. It is of vital importance to establish a sensitive method to detect OTA in various grains. A novel, highly sensitive chemiluminescence immunoassay was developed to determine OTA in wheat, corn, and poultry feed. The immunomagnetic beads were used as solid phase carriers and separators in the competitive chemiluminescence method. Anti-OTA monoclonal antibodies coated on the magnetic beads were applied as the capturing antibodies, in which OTA would compete with OTA-alkaline phosphatase in binding with OTA antibodies. The proposed method exhibited good linearity (R2 ≥ 0.999), adequate OTA recovery rate (83.60-102.50%), and good repeatability. The sensitivity of the proposed method was 2.05 pg/mL. In addition, the method was highly selective and showed no cross-reactions with other mycotoxins (e.g., AFB1, DON, ZEN). The developed method was applied in the analysis of wheat, corn, and two animal feeds successfully. The results obtained by the chemiluminescence method showed a high correlation with those obtained by the HPLC method (correlation coefficient 0.9958). This strategy shows great potential for other toxic and harmful mycotoxin detection. A novel highly rapid and sensitive chemiluminescence immunoassay was established for quantitation of OTA.