In this study, a plastic microdevice based on loop-mediated isothermal amplification (LAMP) was fabricated for the amplification and on-chip fluorescence detection of multiple pathogens. Papers infused with LAMP reagents and specific primers were embedded inside the multiple reaction chambers of the microdevice. A solution containing the target pathogens was injected into the sample chamber, located in the center of the microdevice, and evenly distributed to the reaction chambers simultaneously via centrifugal force. For detection, fisetin, a plant-derived fluorophore, was used as the DNA-intercalating dye. Purified DNAs of Escherichia coli O157:H7 (E. coli O157:H7), Salmonella spp., Staphylococcus aureus (S. aureus), and Cochlodinium polykrikoides were successfully amplified and directly detected on the microdevice, where as low as 0.13 and 0.12 ng μL⁻¹ of the DNA of E. coli O157:H7 and S. aureus, respectively, were identified. In addition, the potential of this microdevice for point-of-care testing was further examined by incorporating on-chip sample purification module and testing using a real sample – milk spiked with Salmonella spp. The thermally lysed milk sample was filtered using polydopamine-coated paper embedded inside a sample chamber and seamlessly transported into the reaction chambers by centrifugal force for subsequent LAMP followed by direct on-chip detection inside the reaction chambers in which fisetin-soaked papers were embedded. The limit of detection for Salmonella spp. was determined to be approximately 1.7 × 10² CFU mL⁻¹ using the microdevice. This microdevice is safe, easy to use, selective, and sensitive enough for point-of-care testing to identify foodborne pathogens as well as environmentally harmful microorganisms.

中文翻译：

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快速，环保的等温放大微型设备，用于多重检测食源性病原体†

在这项研究中，制造了一种基于环介导的等温扩增（LAMP）的塑料微型设备，用于多种病原体的扩增和片上荧光检测。装有LAMP试剂和特异引物的纸张被嵌入微型设备的多个反应室内。将包含目标病原体的溶液注入位于微型设备中心的样品室中，并同时通过离心力均匀地分布到反应室中。为了进行检测，将fisetin（一种植物来源的荧光团）用作DNA嵌入染料。的纯化的DNA大肠杆菌中O157：H7（大肠杆菌O157：H7），沙门氏菌。菌属，金黄色葡萄球菌（成功地扩增了金黄色葡萄球菌（S. aureus）和Cochlodinium polykrikoides，并在微型设备上直接检测到它们，分别鉴定出低至大肠杆菌O157：H7和金黄色葡萄球菌的DNA分别低至0.13和0.12 ngμL ^-1。此外，通过结合片上样品纯化模块并使用真实样品（掺有沙门氏菌的牛奶）进行测试，进一步检验了这种微型设备在即时检验中的潜力spp。使用嵌入样品室内部的聚多巴胺涂层纸过滤热裂解的牛奶样品，并通过离心力将其无缝运输到反应室中以进行后续的LAMP，然后在反应室中直接进行芯片上检测，其中嵌入了非瑟酮浸泡过的纸。沙门氏菌属的检测极限。使用微型设备确定的样品大约为1.7×10 ² CFU mL ^-1。该微型设备安全，易于使用，具有选择性，并且足够灵敏，可以进行即时诊断以识别食源性病原体以及对环境有害的微生物。