Integrated gold superparticles into lateral flow immunoassays for the rapid and sensitive detection of Escherichia coli O157:H7 in milk
Integrated gold superparticles into lateral flow immunoassays for the rapid and sensitive detection of Escherichia coli O157:H7 in milk
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DOI：
10.3168/jds.2019-17934
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发表时间：
2020-08-01
影响因子：
3.5
通讯作者：
Xiong, Yonghua
中科院分区：
文献类型：
--
作者：
Li, Yu;Chen, Xirui;Xiong, Yonghua
大肠杆菌 O157:H7 是一种常见的有害食源性病原体，在低传染剂量下即可引起严重疾病。用于快速筛查食品中大肠杆菌 O157:H7 的传统侧流免疫分析 (LFIA) 由于依赖亮度不足的 20 至 40 nm 金纳米粒子 (AuNP) 作为标记，因此灵敏度较低。为了解决这个问题，我们首次报道了利用蒸发诱导自组装方法将大量小 AuNP 封装到聚合物纳米珠中，成功合成了金超粒子 (GSP)。结果表明，与 LFIA 中最广泛使用的 40 nm AuNP 相比，所得的 GSP 表现出显着增强的吸光度。此外，GSP 的吸光度可以通过改变 GSP 尺寸轻松调节。在优化条件下，使用尺寸为342 nm的GSP作为LFIA信号报告仪，实现了牛奶中大肠杆菌O157:H7的快速、灵敏测定，检测限为5.95 x 10(2) cfu/mL，相对于传统的40 nm AuNP-LFIA方法提高了约32倍。我们进一步证明了所提出的 GSP-LFIA 条带的选择性、准确性、可靠性和实用性。总之，这项工作提供了一种使用组装的 GSP 作为标记来提高 LFIA 灵敏度的新策略，并在快速、灵敏地检测食源性病原体方面展现出巨大的潜力。
Escherichia coli O157:H7 is a common harmful food-borne pathogen that can cause severe diseases at low infectious doses. Traditional lateral flow immunoassay (LFIA) for the rapid screening of E. coli O157:H7 in food suffers from low sensitivity due to its dependence on 20- to 40-nm gold nanoparticles (AuNP) with insufficient brightness as labels. To address this issue, we reported for the first time the successful synthesis of gold superparticles (GSP) by encapsulating numerous small AuNP into a polymer nanobead using an evaporation-induced self-assembly method. Results indicated that the resultant GSP exhibited remarkably enhanced absorbance compared with the most widely used 40 nm AuNP in LFIA. In addition, the absorbance of GSP could be easily tuned by varying GSP sizes. Under optimized conditions, we achieved a rapid and sensitive determination of E. coli O157:H7 in milk with a detection limit of 5.95 x 10(2) cfu/mL when using the GSP with a size of 342 nm as LFIA signal reporters, exhibiting improvement of approximately 32-fold relative to the conventional 40 nm AuNP-LFIA method. We further demonstrated the selectivity, accuracy, reliability, and practicality of the proposed GSP-LFIA strip. In summary, this work offers a new strategy for improving LFIA sensitivity using assembled GSP as markers and demonstrates huge potential in rapidly and sensitively detecting foodborne pathogens.