Rapid isolation of Escherichia coli from water samples using magnetic microdiscs
Rapid isolation of Escherichia coli from water samples using magnetic microdiscs
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DOI：
10.1016/j.snb.2019.04.043
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发表时间：
2019-07-15
影响因子：
8.4
通讯作者：
McLamore, Eric S.
中科院分区：
文献类型：
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作者：
Castillo-Torres, Keisha Y.;Arnold, David P.;McLamore, Eric S.
这项工作介绍了一种使用“细菌大小”的镀金磁性微盘（直径 1.5 μm，厚度 80 nm）快速分离目标细菌细胞的方法。这些微盘带有 DNA 适配体，用于选择性分离大肠杆菌。细胞来自实验室制备的水样和环境水样，浓度低至 10(2) CFU/100 mL，无需富集。该微盘平台能够使用荧光标记物（例如 SYTO9、碘化丙啶和碳量子点）对磁捕获盘进行活力测定，从而在单次分析中提供检测和活力步骤。这种重力驱动分离技术的重要性在于能够使用简单的现场部署设备一步从相对较大的样品体积（高达 100 mL）中快速分离靶细胞，而无需使用复杂的设备或能源。该技术可立即应用于农业用水中粪便指标（大肠杆菌）的快速（< 45 分钟）分离和检测，如果添加浓缩步骤，还可用于饮用水分析。除了靶向大肠杆菌之外，该平台还可用于基于微盘与其他生物受体（例如适体、凝集素、噬菌体或肽）的功能化来靶向其他细胞。
This work introduces a method for rapid isolation of target bacterial cells using "bacteria-sized," gold-coated magnetic microdiscs (1.5 mu m in diameter, 80 nm in thickness). These microdiscs are functionalized with DNA aptamers for selectively isolating Escherichia coll. cells from lab-prepared and environmental water samples at concentrations as low as 10(2) CFU/100 mL with no enrichment. This microdisc platform enables viability assay on the magnetically captured discs using fluorescent markers such as SYTO9, propidium iodide, and carbon quantum dots, providing both a detection and viability step in a single analysis. The significance of this gravity-driven separation technique is the ability to rapidly isolate target cells from relatively large sample volumes (up to 100 mL) with simple field-deployable apparatus in one step, without the use of complicated equipment or energy. This technique has immediate application for rapid ( < 45 min) isolation and detection of fecal indicators (E. coli) in agricultural water and can be used for drinking water analysis if an enrichment step is added. In addition to targeting E. coli, the platform can be used for targeting other cells based on functionalization of the microdiscs with other bioreceptors such as aptamers, lectins, phages, or peptides.