Novel dual immunochromatographic test strip based on double antibodies and biotin-streptavidin system for simultaneous sensitive detection of aflatoxin M1 and ochratoxin A in milk

The coexistence of mycotoxins in agricultural products poses a serious threat to food safety. This study developed a dual immunochromatographic test strips (DICTS) method based on double antibodies labeled with time resolved fluorescent microspheres (TRFM) to realize simultaneous rapid detection of aflatoxin M1 (AFM1) and ochratoxin A (OTA) in milk. As bridge antibody, the polyclonal antibody (pAb) was first conjugated with the TRFM and then with the monoclonal antibody (mAb). Meanwhile, a biotin-streptavidin system was introduced to replace the traditional goat anti-mouse Immunoglobulin G, thus providing a stable signal on the control line. After optimization, the detection limit of AFM1 and OTA in milk was respectively 0.018 and 0.036 ng/mL. The recoveries of intraassay and interassay experiments ranged from 89.65% to 103.99%. The accuracy, repeatability, and specificity of the developed TRFM-DICTS were estimated. The results of TRFM-DICTS showed a high consistency with those of the ultrahigh-performance liquid chromatography-tandem mass spectrometry.

Automated summary

This study developed a dual immunochromatographic test strips method based on double antibodies labeled with time resolved fluorescent microspheres to realize simultaneous rapid detection of AFM1 and OTA in milk. The method showed low detection limits and good accuracy, repeatability, and specificity.