Chiu Ricky Y T, Jue Erik, Yip Allison T, Berg Andrew R, Wang Stephanie J, Kivnick Alexandra R, Nguyen Phuong T, Kamei Daniel T
Department of Bioengineering, University of California, 420 Westwood Plaza, 5121J Engineering V, P.O. Box 951600, Los Angeles, CA 90095-1600, USA.
Lab Chip. 2014 Aug 21;14(16):3021-8. doi: 10.1039/c4lc00532e. Epub 2014 Jun 20.
The lateral-flow immunoassay (LFA) is an inexpensive point-of-care (POC) paper-based diagnostic device with the potential to rapidly detect disease biomarkers in resource-poor settings. Although LFA is inexpensive, easy to use, and requires no laboratory equipment, it is limited by its sensitivity, which remains inferior to that of gold standard laboratory-based assays. Our group is the only one to have previously utilized various aqueous two-phase systems (ATPSs) to enhance LFA detection. In those studies, the sample was concentrated by an ATPS in a test tube and could only be applied to LFA after it had been extracted manually. Here, we bypass the extraction step by seamlessly integrating a polyethylene glycol-potassium phosphate ATPS with downstream LFA detection in a simple, inexpensive, power-free, and portable all-in-one diagnostic device. We discovered a new phenomenon in which the target biomarkers simultaneously concentrate as the ATPS solution flows through the paper membranes, and our device features a 3-D paper well that was designed to exploit this phenomenon. Studies with this device, which were performed at room temperature in under 25 min, demonstrated a 10-fold improvement in the detection limit of a model protein, transferrin. Our next-generation LFA technology is rapid, affordable, easy-to-use, and can be applied to existing LFA products, thereby providing a new platform for revolutionizing the current state of disease diagnosis in resource-poor settings.
侧向流动免疫分析（LFA）是一种廉价的即时检测（POC）纸质诊断设备，有潜力在资源匮乏地区快速检测疾病生物标志物。尽管LFA价格低廉、使用方便且无需实验室设备，但其灵敏度有限，仍低于基于实验室的金标准检测方法。我们的团队是此前唯一利用各种双水相系统（ATPS）来增强LFA检测的团队。在那些研究中，样品在试管中通过ATPS进行浓缩，并且只有在手动提取后才能应用于LFA。在此，我们通过在一个简单、廉价、无电源且便携的一体化诊断设备中，将聚乙二醇 - 磷酸钾ATPS与下游LFA检测无缝整合，绕过了提取步骤。我们发现了一种新现象，即当ATPS溶液流经纸质膜时，目标生物标志物会同时浓缩，并且我们的设备具有一个三维纸孔，其设计目的就是利用这一现象。使用该设备在室温下进行的研究在不到25分钟内完成，结果表明模型蛋白转铁蛋白的检测限提高了10倍。我们的下一代LFA技术快速、经济实惠、易于使用，并且可以应用于现有的LFA产品，从而为变革资源匮乏地区疾病诊断的现状提供了一个新平台。
