Active Junctions to Improve Sensitivity and Detection Limit of a Microdevice Based on Coulometry Coupled with Silver Metallization
Active Junctions to Improve Sensitivity and Detection Limit of a Microdevice Based on Coulometry Coupled with Silver Metallization
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DOI：
10.1002/elan.201800825
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发表时间：
2019-09-01
期刊：
影响因子：
3
通讯作者：
Suzuki, Hiroaki
中科院分区：
文献类型：
--
作者：
Anshori, Isa;Takie, Shuichi;Suzuki, Hiroaki
为了实现微型化和与微流体的耦合，电化学装置是有利的。特别是，库仑法是分析非常小体积溶液中成分的有效工具。将被分析物在两个通道分离的同一Pt电极上转化为银，用库仑法测定银的量，可以显著提高库仑法的灵敏度和检出限。我们证明了Pt电极的两个部分的阴极和阳极电位可以移动，反应可以通过用具有氧化还原活性末端的金属线代替连接两个流动通道的液体结来加速。这反过来又提高了设备的灵敏度和检测极限。这种效应也可以通过直接对流道中的溶液施加电压来观察到。过氧化氢（H2O2）的检出限为2.4 nM。
For achieving miniaturization and coupling with microfluidics, electrochemical devices are advantageous. In particular, coulometry is an effective tool to analyze components in solutions of very small volumes. The sensitivity and detection limit of coulometry can be improved remarkably by converting an analyte into Ag on the same Pt electrode separated in two flow channels and measuring the amount of Ag using coulometry. We demonstrate that the cathodic and anodic potentials of both parts of the Pt electrode can be shifted and reactions can be accelerated by replacing the liquid junction connecting the two flow channels by a metal wire with redox active ends. This in turn improves the sensitivity and detection limit of the device. This effect can also be observed by directly applying a voltage to the solutions in the flow channels. The achieved detection limit for hydrogen peroxide (H2O2) was 2.4 nM.