Single-Impact Electrochemistry in Paper-Based Microfluidics.
Single-Impact Electrochemistry in Paper-Based Microfluidics.
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DOI：
10.1021/acssensors.1c02703
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发表时间：
2022-03
期刊：
影响因子：
8.9
通讯作者：
L. Weiß;Georg Lubins;Emir Music;P. Rinklin;M. Banzet;Hu Peng;K. Terkan;D. Mayer;B. Wolfrum-B.-W
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文献类型：
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作者：
L. Weiß;Georg Lubins;Emir Music;P. Rinklin;M. Banzet;Hu Peng;K. Terkan;D. Mayer;B. Wolfrum-B.-W
微流控纸基分析设备(μPad)经历了一个前所未有的成功故事。特别是，到今天为止，大多数人可能已经接触到了他们最著名的两个例子之一，─怀孕或SARS-CoV-2抗原测试。然而，它们的传感性能受到纳米颗粒团聚的光学读数的限制，这通常只允许定性测量。相比之下，单次冲击电化学提供了通过解决单个物种在微电极上的碰撞来量化PM范围以外的物种浓度的可能性。在这项工作中，我们通过将蜡纹微通道与微电极阵列相结合来研究将随机传感集成到μ焊盘设计中，以通过氧化溶解来检测银纳米颗粒(AgNP)。在这样做的过程中，我们展示了在芯片上参考配置中解决单个纳米粒子碰撞的可能性。为了模拟侧向流动结构，我们沿着微通道将先前干燥的AgNPs冲向电极阵列，在那里我们能够记录纳米颗粒的撞击。因此，单次冲击电化学提供了一个很有希望的候选方案，可以将基于横向流动的传感器的限制扩展到目前的应用之外，以便在现场快速而可靠地检测非常稀薄的物质。
Microfluidic paper-based analytical devices (μPADs) have experienced an unprecedented story of success. In particular, as of today, most people have likely come into contact with one of their two most famous examples─the pregnancy or the SARS-CoV-2 antigen test. However, their sensing performance is constrained by the optical readout of nanoparticle agglomeration, which typically allows only qualitative measurements. In contrast, single-impact electrochemistry offers the possibility to quantify species concentrations beyond the pM range by resolving collisions of individual species on a microelectrode. Within this work, we investigate the integration of stochastic sensing into a μPAD design by combining a wax-patterned microchannel with a microelectrode array to detect silver nanoparticles (AgNPs) by their oxidative dissolution. In doing so, we demonstrate the possibility to resolve individual nanoparticle collisions in a reference-on-chip configuration. To simulate a lateral flow architecture, we flush previously dried AgNPs along a microchannel toward the electrode array, where we are able to record nanoparticle impacts. Consequently, single-impact electrochemistry poses a promising candidate to extend the limits of lateral flow-based sensors beyond current applications toward a fast and reliable detection of very dilute species on site.