College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China.
Institute for Agro-food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Laboratory of Quality and Safety Risk Assessment for Agro-products (Shanghai), Ministry of Agriculture, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.
Toxins (Basel). 2019 Jul 28;11(8):447. doi: 10.3390/toxins11080447.
With the widespread contamination of ochratoxin A (OTA), it is of significant importance for detecting OTA in foods and traditional Chinese medicine (TCM). In this study, a novel label-free fluorescent aptasensor utilizing the interaction between OTA-triggered antiparallel G-quadruplex and (N-methyl-4-pyridy) porphyrin (TMPyP) for the rapid and sensitive determination of OTA was established. The fluorescence of CdTe quantum dots (QDs) could be quenched by TMPyP. In the presence of analyte (OTA), the aptamer could recognize OTA and transform from a random coil to the antiparallel G-quadruplex. The interaction between G-quadruplex and TMPyP could release CdTe QDs from TMPyP, and thus recover the fluorescence of CdTe QDs. Under optimized conditions, the detection limit of the designed aptasensor was 0.16 ng mL, with a linear range of 0.2 to 20 ng mL. Furthermore, this aptasensor showed high selectivity toward OTA against other structural analogs and other mycotoxins, and was successfully applied in samples. The presented aptasensor for OTA detection could be a promising tool for the field monitoring of food and TCM.
由于赭曲霉毒素 A（OTA）的广泛污染，因此检测食品和中药（TCM）中的 OTA 具有重要意义。在这项研究中，建立了一种新型的无标记荧光适体传感器，利用 OTA 触发的反平行 G-四链体与（N-甲基-4-吡啶基）卟啉（TMPyP）之间的相互作用，用于快速灵敏地测定 OTA。碲化镉量子点（QDs）的荧光可以被 TMPyP 猝灭。在存在分析物（OTA）的情况下，适体可以识别 OTA 并从无规卷曲转变为反平行 G-四链体。G-四链体与 TMPyP 之间的相互作用可以将 CdTe QDs 从 TMPyP 中释放出来，从而恢复 CdTe QDs 的荧光。在优化条件下，设计的适体传感器的检测限为 0.16 ng mL，线性范围为 0.2 至 20 ng mL。此外，该适体传感器对 OTA 具有较高的选择性，可与其他结构类似物和其他霉菌毒素区分开，并已成功应用于样品中。用于 OTA 检测的这种适体传感器可能成为食品和 TCM 现场监测的有前途的工具。
