An enhanced enzyme-linked aptamer assay for the detection of zearalenone based on gold nanoparticles
A novel enhanced enzyme-linked aptamer assay (ELAA) for the detection of zearalenone (ZEN) was developed based on gold nanoparticles (AuNPs) modified with an aptamer and horseradish peroxidase (HRP). In this assay, the aptamer was used as a recognition probe to competitively bind with coated ZEN-BSA on a microplate and ZEN in samples. AuNPs with high surface areas were used as a carrier to immobilize more amounts of HRP labelled aptamer probe, which can amplify the colorimetric signal by enhancing catalysis of the HRP enzyme compared with the traditional enzyme-linked method. Under the optimal conditions, the enhanced ELAA presented a good linearity in the range of 0.1–160 ng mL−1 and the limit of detection was 0.08 ng mL−1 for ZEN detection. In addition, the enhanced ELAA had no cross reactivity with other mycotoxins and showed good recoveries in spiked corn oil samples. These results indicated that the AuNP enhanced ELAA provided a new approach with simplicity, and high sensitivity and specificity for the detection of ZEN in foodstuff.