Novel Enzyme-Linked Aptamer Assay for the Determination of Aflatoxin B1 in Peanuts

A novel enzyme-linked aptamer assay is reported for the determination of aflatoxin B1 (AFB1). AFB1 can competitively bind with the immobilized biotin-aptamer and release biotin complementary DNA, leading to the gradual fading of the detection system color with increasing of AFB1 concentration. In the absence of AFB1, the biotinylated complementary DNA is not be released from the fixed aptamer. Therefore, the enzyme reaction occurs in the detection system. Under the optimized experimental conditions, the proposed method possessed a wide linear range for AFB1 from 1 to 80 ng/mL (R2 of 0.990) with a low detection limit of 0.36 ng/mL. The method was then applied to detect uncontaminated peanuts fortified with different concentrations of AFB1. The recovery values were from 82.60% to 94.43%, which indicated the proposed method may be used to detect AFB1 in food and has potential for the development of test kits.