Smartphone-based, sensitive RAD detection of urinary tract infection and gonorrhea
Smartphone-based, sensitive RAD detection of urinary tract infection and gonorrhea
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DOI：
10.1016/j.bios.2015.07.014
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发表时间：
2015-12-15
影响因子：
12.6
通讯作者：
Yoon, Jeong-Yeol
中科院分区：
文献类型：
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作者：
Cho, Soohee;Park, Tu San;Yoon, Jeong-Yeol
尿液中细菌的存在可以用来监测尿路感染（UTI）和一些性传播疾病（STD）的发病或预后，如淋病。通常，尿液中细菌的存在是通过在琼脂平板上过夜培养样本，然后进行显微镜检查来确认的。此外，尿液样本中大肠杆菌的存在可以通过测定亚硝酸盐（通过还原尿液中的硝酸盐产生）间接确认，但这并不具有足够的特异性和灵敏度。尿液样本中细菌的种属/菌株鉴定为适当的抗生素治疗选择提供了见解。本研究设计并制作了一种用于检测UTI（大肠杆菌）的微流控纸分析装置。大肠杆菌）和STD（淋病奈瑟菌）。抗大肠coli或抗N.将淋病抗体与亚微米颗粒结合，然后预加载并在每个纸微流体通道的中心干燥。加标E. coli或N.淋病用1%Tween 80孵育5分钟。然后将细菌掺入的尿液样品引入纸微流体通道的入口，其通过毛细管力流过通道。数据证实，蛋白质未被mu PAD过滤，这对于该测定是必需的。尿胆素，负责尿液的黄色外观和绿色荧光发射的组分，被mu PAD过滤，导致显著最小化的假阳性信号。该过滤在mu PAD测定期间同时进行，并且不需要预处理/纯化步骤。抗体结合的颗粒在纸通道的中心免疫凝集。免疫凝集的程度通过在环境照明条件下的角度特异性Mie散射来定量，利用智能手机相机作为检测器。总mu PAD测定时间小于30 s。两种大肠杆菌的检出限均为10 CFU/mL。coli和N.淋病，而市售淋病快速试剂盒显示检测限为10（6）CFU/mL。市售的亚硝酸盐测定试纸也具有10（6）CFU/mL的检测限，但该方法不是基于抗体的，因此特异性不够。通过优化颗粒浓度，我们还能够将测定的线性范围扩展到10（7）CFU/mL。所提出的原型将用作低成本、即时护理、灵敏的尿液分析生物传感器，以监测来自人尿液的UTI和淋病。(C)2015 Elsevier B. V.版权所有。
The presence of bacteria in urine can be used to monitor the onset or prognosis of urinary tract infection (UTI) and some sexually-transmitted diseases (STDs), such as gonorrhea. Typically, bacteria's presence in urine is confirmed by culturing samples overnight on agar plates, followed by a microscopic examination. Additionally, the presence of Escherichia coli in a urine sample can be indirectly confirmed through assaying for nitrite (generated by reducing nitrate in urine), however this is not sufficiently specific and sensitive. Species/strains identification of bacteria in a urine sample provides insight to appropriate antibiotic treatment options. In this work, a microfluidic paper analytical device (mu PAD) was designed and fabricated for evaluating UTI (E. coli) and STD (Neisseria gonorrhoeae) from human urine samples. Anti-E. coli or anti-N. gonorrhoeae antibodies were conjugated to submicron particles then pre-loaded and dried in the center of each paper microfluidic channel. Human urine samples (undiluted) spiked with E. coli or N. gonorrhoeae were incubated for 5 min with 1% Tween 80. The bacteria-spiked urine samples were then introduced to the inlet of paper microfluidic channel, which flowed through the channel by capillary force. Data confirms that proteins were not filtered by mu PAD, which is essential for this assay. Urobilin, the component responsible for the yellow appearance of urine and green fluorescence emission, was filtered by mu PAD, resulting in significantly minimized false-positive signals. This filtration was simultaneously made during the mu PAD assay and no pretreatment/purification step was necessary. Antibody-conjugated particles were immunoagglutinated at the center of the paper channel. The extent of immunoagglutination was quantified by angle-specific Mie scatter under ambient lighting conditions, utilizing a smartphone camera as a detector. The total mu PAD assay time was less than 30 s. The detection limit was 10 CFU/mL for both E. coli and N. gonorrhoeae, while commercially available gonorrhea rapid kit showed a detection limit of 10(6) CFU/mL. A commercially available nitrite assay test strip also had a detection limit of 10(6) CFU/mL, but this method is not antibody-based and thus not sufficiently specific. By optimizing the particle concentration, we were also able to extend the linear range of the assay up to 10(7) CFU/mL The proposed prototype will serve as a low-cost, point-of-care, sensitive urinalysis biosensor to monitor UTI and gonorrhea from human urine. (C) 2015 Elsevier B.V. All rights reserved.