【作者】 贾飞； 徐雷； 闫文杰； 邬威； 喻倩倩； 田晓静； 戴瑞彤； 李兴民；

【Author】 Jia Fei;Xu Lei;Yan Wenjie;Wu Wei;Yu Qianqian;Tian Xiaojing;Dai Ruitong;Li Xingmin;College of Food Science and Nutritional Engineering,China Agricultural University;College of Applied Arts and Science,Beijing Union University;

【机构】 中国农业大学食品科学与营养工程学院； 北京联合大学应用文理学院；

【摘要】 本文构建了一种磁弛豫时间适配体传感器快速检测铜绿假单胞菌。本传感器基于适配体识别技术和磁弛豫时间原理。首先利用酰胺反应将铜绿假单胞菌适配体共价结合于超顺磁性纳米材料表面。超顺磁性纳米材料的磁放大能力和适配体识别体系的高亲和力保证检测方法的灵敏度和选择性。在铜绿假单胞菌菌存在条件下,适配体能特异性将铜绿假单胞菌菌捕获,引起超顺磁性纳米粒子的聚集,从而导致传感器中弛豫时间T₂的变化。根据弛豫时间T₂的变化实现对铜绿假单胞菌的定量检测。在优化条件下,T₂的变化差值与铜绿假单胞菌菌菌液浓度的对数值成线性关系,线性范围为10²cfu/mL¹0⁶cfu/mL,检测限为50cfu/mL（S/N\=3）。将构建的适配体传感器用于食品和饮用水中铜绿假单胞菌的检测,并用平板计数法进行验证,证明本方法可用于实际样本的检测。同时,本文构建的传感器灵敏度高、造价低廉、简便易用,能够应用于其他食源性致病菌的检测当中。更多还原

【Abstract】 A simple,rapid and sensitive magnetic relaxation switch（MRSw） aptasensor was developed for the detection of Pseudomonas aeruginosa.This aptasensor is based on an aptamer-recognition system and magnetic relaxation switch assay.The anti-P.aeruginosa aptamer was covalently bound to the superparamagnetic iron oxide（SPIO） nanoparticles through amide bonds.The magnetic amplification of SPIO nanoparticles and the high affinity of the aptamer-recognition system ensured the highly sensitivity and selectivity of the assay.When incubated with P.aeruginosa,the aptamer selectively captured target bacteria and hence affected the formation of SPIO aggregates,resulting in a dramatic increase in the spin-spin relaxation time（T₂）,which can be utilized to quantify the bacteria.Under optimized conditions,the aptasensor possessed a linear range of10²cfu/mL to 10⁶cfu/mL and a detection limit of 50cfu/mL（S/N = 3）.The proposed method was then applied to detect P.aeruginosa in real food and drinking water samples and was validated by the traditional plate counting method.The results showed that the MRSw aptasensor is a promising platform for the determination of P.aeruginosa and could be extended to other food-borne bacteria or biomolecules due to its high sensitivity,low-cost,simplicity and ease of use.更多还原