Lateral flow assay (LFA) has been a valuable diagnostic tool in many important fields where rapid, simple, and on-site detection is required, for applications such as pregnancy tests and infectious disease prevention. Currently, two types of LFAs are available: lateral flow immunoassay (LFIA) and nucleic acid lateral flow assay (NALFA). Both are generally used for the testing of proteins and nucleic acids. However, enzyme activities and small molecules without the corresponding binding partner cannot be detected by the existing LFAs. In this paper, we introduce a LFA approach termed affinity-switchable lateral flow assay (ASLFA) to overcome the limitations. The detection principle is based on the switchable binding between the affinity-switchable biotin (ASB) probe and avidin protein. In the presence of the target molecule, the activated ASB probe would be captured by the avidin, thereby leaving a distinct test line on the membrane. The ASLFA concept was demonstrated by testing the F ion, NADH cofactor, and nitroreductase activity. Thus, this general ASLFA can be used for the rapid detection of molecules that cannot be accessed by the classical LFAs.

中文翻译：

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亲和力可控的横向流动测定

在需要快速，简单和现场检测的许多重要领域中，对于诸如妊娠试验和传染病预防等应用，侧向流动测定（LFA）已经成为一种有价值的诊断工具。当前，有两种类型的LFA：侧向免疫测定（LFIA）和核酸侧向测定（NALFA）。两者通常都用于测试蛋白质和核酸。但是，现有的LFA无法检测到没有相应结合配偶体的酶活性和小分子。在本文中，我们介绍一种方法LFA称为一个ffinity-小号witchable升ateral ˚F低一ssay（ASLFA）来克服这些限制。检测原理基于亲和力可转换生物素（ASB）探针和抗生物素蛋白之间的可转换结合。在靶分子存在的情况下，活化的ASB探针将被抗生物素蛋白捕获，从而在膜上留下明显的测试线。通过测试F离子，NADH辅因子和硝基还原酶活性，证明了ASLFA概念。因此，这种通用的ASLFA可以用于快速检测经典LFA无法访问的分子。