Abstract:ompetitive enzyme-linked aptamer assay for Ochratoxin A (OTA) detection in wine was investigated in this study. The binding of aptamer to the target OTA resulted in the dissociation of the DNA short chain from the aptamer, which was further captured by horseradish peroxidase (HRP). HRP catalyzed 3,3',5,5'.-Tetramethylbenzidine (TMB) substrate and finally leaded to a characteristic change that was detectable by the absorption of ultraviolet at 450 nm. The detection limit of OTA was determined by the linear relationship between OTA concentration and the absorbance. The factors influenced the effect of detection were investigated, including DNA concentration, temperature of hybridization, and blocking buffer solution. This work described the high performance of the competitive enzyme-linked aptamer assay (ELAA) for the determination of OTA. Under the optimal condition, the limit of detection attained was 0.88 μg/L and the linearity was in the range 1 to 100 μg/L. For the OTA detection in wine, the recovery rate was between 92.03% and 106.6%, and the relative standard deviation (RSD, n=5) was within 2.1%. This study validates the competitive ELAA is a useful tool for a rapid detection of OTA in wine.
