Department of Bioengineering , University of California, Los Angeles , Los Angeles , California 90095 , United States.
Division of Advanced Prosthodontics & Weintraub Center for Reconstructive Biotechnology School of Dentistry , University of California, Los Angeles , Los Angeles , California 90095 , United States.
Anal Chem. 2019 Sep 17;91(18):12046-12054. doi: 10.1021/acs.analchem.9b03105. Epub 2019 Aug 30.
Infectious diseases remain one of the leading causes of deaths in developing countries because of a lack of basic sanitation, healthcare clinics, and centralized laboratories. Paper-based rapid diagnostic tests, such as the lateral-flow immunoassay (LFA), provide a promising alternative to the traditional laboratory-based tests; however, they typically suffer from having a poor sensitivity. Biomarker preconcentration and signal enhancement are two common methods to improve the sensitivity of paper-based assays. While effective, these methods often require multiple liquid handling steps which are not ideal for use by untrained personnel in a point-of-care setting. Our lab previously discovered the phenomenon of an aqueous two-phase system (ATPS) separating on paper, which allowed for the seamless integration of concentration and detection of biomarkers on the LFA. In this work, we have extended the functionality of an ATPS separating on paper to automate the sequential delivery of signal enhancement reagents in addition to concentrating biomarkers. The timing of reagent delivery was controlled by changing the initial composition of the ATPS. We applied this technology to automate biomarker concentration and nanozyme signal enhancement on the LFA, resulting in a 30-fold improvement in detection limit over the conventional LFA when detecting , all while maintaining a single application step.
传染病仍然是发展中国家死亡的主要原因之一，因为这些国家缺乏基本的卫生设施、医疗诊所和集中式实验室。基于纸的快速诊断测试，如侧向流动免疫分析（LFA），为传统的基于实验室的测试提供了一个有前途的替代方案；然而，它们通常存在灵敏度差的问题。生物标志物预浓缩和信号增强是提高基于纸张的分析灵敏度的两种常用方法。虽然这些方法有效，但它们通常需要多个液体处理步骤，这对于在护理点环境中未经训练的人员来说并不理想。我们实验室之前发现了在纸上分离双水相系统（ATPS）的现象，这使得在 LFA 上对生物标志物进行无缝浓缩和检测成为可能。在这项工作中，我们扩展了在纸上分离 ATPS 的功能，除了浓缩生物标志物外，还可以自动递增强化试剂。通过改变 ATPS 的初始组成来控制试剂的输送时间。我们将这项技术应用于 LFA 上的生物标志物浓缩和纳米酶信号增强的自动化，当检测时，与传统的 LFA 相比，检测限提高了 30 倍，同时保持了单个应用步骤。
