以近红外荧光碳量子点为探针, 以赭曲霉毒素A(OTA)适配体为特异性结合体, 建立了近红外荧光核酸适体OTA传感检测平台。研究显示, 所建立的近红外荧光核酸适体OTA传感对OTA具有高特异性, 其他真菌毒素无明显干扰。研究了传感体系组成、pH值、孵化时间等因素对近红外荧光传感性能的影响, 确定了最优检测条件。在最优检测条件下, OTA 浓度在0.015~1.5 ng·mL-1范围与体系荧光强度恢复呈良好线性关系, 检测限为8 pg·mL-1。该方法用于连翘、葛根、莲子、麦芽、陈皮、甘草等中草药中痕量OTA的测定, 发现这些中药材都存在赭曲霉毒素A的污染。

A novel near-infrared fluorescence aptasensor was developed using near-infrared fluorescence carbon quantum dots as probes, ochratoxin A(OTA) aptamers as specific binding OTA. The other mycotoxins were no interferences in the determination of OTA. The influence factors on the performance of the aptasensors were investigated including components of aptasensors, pH of the solution, incubation period. The optimum conditions were determined. Under the optimum conditions, a linear fluorescence signal response to OTA concentration was obtained over a wide OTA concentration range of 0.015-1.50 ng·mL-1 with a detection limit of 8 pg·mL-1. The proposed method was employed in the determination of trace OTA in forsythia suspense, radix puerariae, semen nelumbinis, malt, pericarpium citri reticulatae and radix liquiritiae successfully.