An innovative electrochemical aptasensor based on the dual signal amplification strategy of gold nanowires and bifunctional DNA nanoflowers

Herein, an innovative electrochemical aptasensor based on the dual signal amplification strategy of gold nanowires (AuNWs) as well as bifunctional DNA nanoflowers was designed to detect ochratoxin A (OTA). For the first time, the RCA-induced bifunctional DNA nanoflowers with both target recognition and signal labeling functions were used for OTA detection. The AuNWs was used as the electrode modification material and MB was used as the signal tag. The fabricated aptasensor exhibited a linear range of 1 x 10(-4)similar to 10 ng/mL, with limits of detection (LOD, S/N = 3) and limits of quantification (LOQ, S/N = 10) as low as 1.12 fg/mL and 3.73 fg/mL, respectively. This aptasensor exhibited satisfying specificity, reproducibility, stability and repeatability toward OTA detection. This strategy has been successful in detecting OTA in wheat flour, camellia bean, and the good results were also obtained for the quality control samples of corn meal, indicating a new detection model for trace pollutants analysis and environmental monitoring.