Chongqing Key Laboratory of Micro-Nano Systems and Smart Transduction, Chongqing Key Laboratory of Colleges and Universities on Micro-Nano Systems Technology and Smart Transducing, Collaborative Innovation Center on Micro-Nano Transduction and Intelligent Eco-Internet of Things, Chongqing Academician and Expert Workstation, Chongqing Technology and Business University, Nan'an District, Chongqing, 400067, China; Department of Microsystems (IMS), Faculty of Technology, Natural Sciences and Maritime Sciences, University of South-Eastern Norway, Postboks 235, 3603, Kongsberg, Norway.
Department of Microsystems (IMS), Faculty of Technology, Natural Sciences and Maritime Sciences, University of South-Eastern Norway, Postboks 235, 3603, Kongsberg, Norway.
Talanta. 2022 Apr 1;240:123157. doi: 10.1016/j.talanta.2021.123157. Epub 2021 Dec 17.
Sandwich lateral flow assay (LFA) is one of the most successfully commercialized paper-based biosensors, which offers a rapid, low-cost, one-step assay. Despite its advantages, conventional sandwich LFA is fundamentally limited by the high-dose "hook" effect-a phenomenon that occurs at very high analyte concentrations and results in false-negative results. In this paper, we present a novel strategy of automatic timed detection antibody release to mitigate the hook effect in sandwich LFA without additional manual steps. We introduced an intermediate pad treated with saturated sucrose solution to regulate the flow between the nitrocellulose membrane and the conjugate pad in order to delay the reaction between detection antibodies and analytes. Using C-reactive protein (CRP) as a representative analyte, we demonstrated that our strategy exhibited a range of detection 10 times wider than that of our conventional LFA, without sacrificing the limit of detection. Comparing to other published strategies, our work could offer a one-step, cost-effective approach that is closely unified with the benefits of the LFA.
三明治侧向流分析（LFA）是最成功商业化的基于纸的生物传感器之一，它提供了快速、低成本、一步式分析。尽管具有这些优势，但传统的三明治 LFA 从根本上受到高剂量“钩状”效应的限制 - 这种现象发生在非常高的分析物浓度下，导致假阴性结果。在本文中，我们提出了一种自动定时检测抗体释放的新策略，可在无需额外人工步骤的情况下减轻三明治 LFA 中的钩状效应。我们引入了一个用饱和蔗糖溶液处理的中间垫，以调节硝酸纤维素膜和结合垫之间的流动，从而延迟检测抗体与分析物之间的反应。使用 C 反应蛋白（CRP）作为代表性分析物，我们证明我们的策略表现出比我们传统 LFA 宽 10 倍的检测范围，而不会牺牲检测限。与其他已发表的策略相比，我们的工作可以提供一种一步式、具有成本效益的方法，与 LFA 的优势紧密结合。
