Ultrasensitive monitoring strategy of PCR‐like levels for zearalenone contamination based DNA barcode

BACKGROUND The ultrasensitive monitoring strategy of zearalenone (ZEN) is essential and desirable for food safety and human health. In the present study, a coupling of gold nanoparticles‐DNA barcode and direct competitive immunoassay‐based real‐time polymerase chain reaction signal amplification (RT‐IPCR) for ZEN close to the sensitivity of PCR‐like levels is described and evaluated. RESULTS The RT‐IPCR benefited from the use of a DNA barcode and RT‐PCR detection strategy, thus resulting in ultrasensitive and simple detection for ZEN. Under the optimal RT‐IPCR, the linear range of detection was from 0.5 to 1000 pg mL−1 and the limit of detection was 0.5 pg mL−1, which was 400‐fold lower than the enzyme‐linked immunosorbent assay. The detection procedure was simplified and the detection time was shortened. The specificity, accuracy and precision of the RT‐IPCR confirmed a high performance. ZEN‐positive contamination levels were from 0.056 to 152.12 ng g−1 by the RT‐IPCR, which was demonstrated to be highly reliable by liquid chromatography‐tandem mass spectrometry. CONCLUSION The proposed RT‐IPCR could be used as an alternative for detecting ZEN with satisfactory ultrasensitivity, simplicity, low cost and high‐throughput. The present study could provide a strategy for the ultrasensitive detection of the small molecule with a simple and practical approach, which has significant appeal and application prospects.