Dissolvable fluidic time delays for programming multi-step assays in instrument-free paper diagnostics.
Dissolvable fluidic time delays for programming multi-step assays in instrument-free paper diagnostics.
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DOI：
10.1039/c3lc50178g
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发表时间：
2013-07-21
期刊：
影响因子：
6.1
通讯作者：
Yager P
中科院分区：
文献类型：
--
作者：
Lutz B;Liang T;Fu E;Ramachandran S;Kauffman P;Yager P
横向流动测试(LFT)是一种巧妙的快速且易于使用的诊断格式，但它们基本上仅限于可简化为单个化学步骤的分析化学步骤。相比之下，大多数实验室诊断分析依赖于由人或机器执行的多个定时步骤。在这里，我们使用施加到纸上的可溶性糖来创建可编程的流动延迟，并提出了一种使用这些时间延迟来编程自动多步流体协议的纸网络拓扑。将不同浓度的蔗糖溶液(饱和度的10%-70%)添加到纸条中并干燥，以产生几分钟到近一小时的流体延迟。使用糖延迟的简单折叠卡形式被展示为自动化由单个用户激活步骤(折叠卡)启动的四步流体过程；该设备被用于对疟疾诊断生物标记物执行信号放大的夹心免疫分析。这些卡片能够以快速、低成本和易于使用的形式自动执行实验室通常使用的多步分析方案。
Lateral flow tests (LFTs) are an ingenious format for rapid and easy-to-use diagnostics, but they are fundamentally limited to assay chemistries that can be reduced to a single chemical step. In contrast, most laboratory diagnostic assays rely on multiple timed steps carried out by a human or a machine. Here, we use dissolvable sugar applied to paper to create programmable flow delays and present a paper network topology that uses these time delays to program automated multi-step fluidic protocols. Solutions of sucrose at different concentrations (10-70% of saturation) were added to paper strips and dried to create fluidic time delays spanning minutes to nearly an hour. A simple folding card format employing sugar delays was shown to automate a four-step fluidic process initiated by a single user activation step (folding the card); this device was used to perform a signal-amplified sandwich immunoassay for a diagnostic biomarker for malaria. The cards are capable of automating multi-step assay protocols normally used in laboratories, but in a rapid, low-cost, and easy-to-use format.