Exonuclease III assisted electrochemical aptasensor simultaneous detection of aflatoxin B1 and ochratoxin A in grains

The synergistic effect of multiple mycotoxins in cereals increases their toxicity. Therefore, the simultaneous detection of multiple mycotoxins in cereals is of great importance. Exonuclease III (Exo III) assisted electrochemical aptasensor has been used for mycotoxin detection, but simultaneous detection of two mycotoxins has not been previously reported. By utilizing Exo III assisted strand displacement, this study developed an electrochemical aptasensor strategy for the simultaneous detection of aflatoxin B1 (AFB1) and ochratoxin A (OTA). This method demonstrates excellent detection of AFB1 and OTA within the range of 0.001-500 ng mL-1, with detection limits as low as 0.229 pg mL-1 for AFB1 and 0.564 pg mL-1 for OTA. The electrochemical aptasensor was successfully applied to analyze grain samples, and the sensor has good specificity, stability and repeatability. The adapter provides simultaneous detection of AFB1 and OTA in food in a fast, simple and highly sensitive platform.