Lv Zhenzhen, Chen Ailiang, Liu Jinchuan, Guan Zheng, Zhou Yu, Xu Siyuan, Yang Shuming, Li Cheng
College of Food Science, Sichuan Agricultural University, Ya'an, China ; Institute of Quality Standards & Testing Technology for Agro-Products, Key Laboratory of Agro-product Quality and Safety, Chinese Academy of Agricultural Sciences, Beijing, China ; Key Laboratory of Agri-Food Quality and Safety, Ministry of Agriculture, Beijing, China.
Institute of Quality Standards & Testing Technology for Agro-Products, Key Laboratory of Agro-product Quality and Safety, Chinese Academy of Agricultural Sciences, Beijing, China ; Key Laboratory of Agri-Food Quality and Safety, Ministry of Agriculture, Beijing, China.
PLoS One. 2014 Jan 21;9(1):e85968. doi: 10.1371/journal.pone.0085968. eCollection 2014.
Ochratoxin A(OTA) is found to be one of the predominant contaminating mycotoxins in a wide variety of food commodities. To avoid the risk of OTA consumption, the detection and quantitation of OTA level are of great significance. Based on the fact that ssDNA aptamer has the ability to form a double-strand structure with its complementary sequence, a simple and rapid aptamer-based label-free approach for highly sensitive and selective fluorescence detection of OTA was developed by using ultra-sensitive double-strand DNA specific dyes PicoGreen. The results showed that as low as 1 ng/mL of OTA could be detected with a dynamic range of more than 5 orders of magnitude which satisfies the requirements for OTA maximum residue limit in various food regulated by European Commission. With the specificity of aptamer, the assay exhibited high selectivity for OTA against two other analogues (N-acetyl-l-phenylalanine and zearalenone). We also tested the aptasensor practicability using real sample of 1% beer spiked with a series of concentration of OTA and the results show good tolerance to matrix effect. All detections could be achieved in less than 30 min, which provides a simple, quick and sensitive detection method for OTA screening in food safety and could be easily extend to other small molecular chemical compounds detection which aptamer has been selected.
赭曲霉毒素A（OTA）被发现是多种食品商品中主要的污染霉菌毒素之一。为避免摄入OTA的风险，检测和定量OTA水平具有重要意义。基于单链DNA适配体能够与其互补序列形成双链结构这一事实，利用超灵敏的双链DNA特异性染料PicoGreen，开发了一种简单快速的基于适配体的无标记方法，用于高灵敏和选择性荧光检测OTA。结果表明，该方法能够检测低至1 ng/mL的OTA，动态范围超过5个数量级，满足欧盟委员会规定的各类食品中OTA最大残留限量的要求。凭借适配体的特异性，该检测方法对OTA相对于其他两种类似物（N-乙酰-L-苯丙氨酸和玉米赤霉烯酮）表现出高选择性。我们还使用添加了一系列浓度OTA的1%啤酒实际样品测试了适配体传感器的实用性，结果表明其对基质效应具有良好的耐受性。所有检测均可在30分钟内完成，这为食品安全中OTA的筛选提供了一种简单、快速且灵敏的检测方法，并且可以轻松扩展到已筛选出适配体的其他小分子化合物的检测。
