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 B-1 (AFB(1)). AFB(1) 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 AFB(1) concentration. In the absence of AFB(1), 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 AFB(1) from 1 to 80 ng/mL (R-2 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 AFB(1). The recovery values were from 82.60% to 94.43%, which indicated the proposed method may be used to detect AFB(1) in food and has potential for the development of test kits.