中文摘要：快速筛查食品污染是预防和控制食源性疾病暴发的关键。本研究开发了一种超灵敏快速检测大肠杆菌O157:H7的新型荧光生物传感器。该传感器采用双层通道与免疫磁性纳米粒子（MNPS）进行有效浓度目标细菌的特异性分离，以及免疫量子点（QDS）与便携式光学系统进行定量检测。实验首先在高梯度磁场（HGMFs）下，通过免疫磁性纳米粒子在通道中捕获细菌形成MNP细菌复合物。然后，免疫QDS与靶菌反应在通道中形成MNP细菌QDS复合物。最后，采用便携式光学系统对富集的复合物进行检测，并通过获取的的荧光强度确认样品中大肠杆菌O157:H7细胞。结果显示，该传感器能够在2小时内检测到低达14 CFU/ml的大肠杆菌O157:H7，在加标牛奶样品中大肠杆菌的回收率介于95.92%至108.15%之间，表明它能够检测真实样品中大肠杆菌细胞。此外，该生物传感器能够检测体积为10毫升的细菌，并且有可能检测更大体积的细菌以增加其灵敏度。
 
外文摘要：Rapid screening of contaminated foods is the key to prevent and control the outbreaks of foodborne diseases. In this study, a novel fluorescent biosensor was developed for ultrasensitive and rapid detection of E. coli O157:H7.The proposed fluorescent biosensor used the double-layer channel with the immune magnetic nanoparticles (MNPs) for specific separation and efficient concentration of the target bacteria, and the immune quantum dots (QDs) with the portable optical system for quantitative detection of the bacteria. First, the bacteria were captured by the immune MNPs in the channel at the presence of the high  gradient magnetic fields (HGMFs) to form the MNP-bacteria complexes. Then, the immune QDs were used to react with the target bacteria to form the MNP-bacteria-QDs complexes in the channel. Finally, the enriched complexes were collected and detected using the portable optical system to obtain the fluorescence intensity for final determination of the E. coli O157:H7 cells in the sample. This proposed biosensor was demonstrated to be able to detect E. coli O157:H7 as low as 14 CFU/mL within 2 h. The recovery of E. coli in the spiked milk samples ranged from 95.92% to 108.15%, indicating that it was capable of detecting E. coli in real samples. Besides, this proposed biosensor was able to detect the bacteria in the volume of 10 mL, and has the potential to detect the bacteria in a larger volume to increase the sensitivity.
 
外文关键词：fluorescent biosensor; double-layer channel; high gradient magnetic separation; quantum dots; E. coli O157:H7
作者：Li Xue, Lingyan Zheng, Huilin Zhang, Xiu Jin, Jianhan Lin
作者单位：Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture, China Agricultural University, 17 East Qinghua Road, Beijing, 100083 China
期刊名称：Sensors and Actuators B
期刊影响因子：5.401
出版年份：2018
出版刊次：5
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