Luxembourg Institute of Science and Technology (LIST) , 41 Rue du Brill , L-4422 Belvaux , Luxembourg.
MESA+ Institute , University of Twente , Drienerlolaan 5 , 7522 NB Enschede , Netherlands.
Nano Lett. 2018 May 9;18(5):2807-2815. doi: 10.1021/acs.nanolett.7b05054. Epub 2018 Apr 10.
The electrochemical management of the proton concentration in miniaturized dimensions opens the way to control and parallelize multistep chemical reactions, but still it faces many challenges linked to the efficient proton generation and control of their diffusion. Here we present a device operated electrochemically that demonstrates the control of the pH in a cell of ∼140 nL. The device comprises a microfluidic reactor integrated with a pneumatic mechanism that allows the exchange of reagents and the isolation of protons to decrease the effect of their diffusion. We monitored the pH with a fluorescence marker and calculated the final value from the redox currents. We demonstrate a large pH amplitude control from neutral pH values beyond the fluorescence marker range at pH 5. On the basis of the calculations from the Faradaic currents, the minimum pH reached should undergo pH ∼ 0.9. The pH contrast between neutral and acid pH cells can be maintained during periods longer than 15 min with an appropriate design of a diffusion barrier.
在微型化尺寸中对质子浓度进行电化学管理为控制和并行化多步化学反应开辟了道路，但仍面临许多与有效质子生成和控制其扩散相关的挑战。在这里，我们展示了一种通过电化学操作的设备，该设备演示了对约 140 nL 细胞中 pH 值的控制。该设备包括一个微流控反应器，集成了一个气动机构，允许试剂交换和质子隔离，以降低其扩散的影响。我们使用荧光标记物监测 pH 值，并从氧化还原电流计算最终值。我们证明了从中性 pH 值到荧光标记范围以外的 pH 值的大 pH 值幅度控制，其值超过 pH 值 5。基于法拉第电流的计算，最小 pH 值应降至 pH 值约 0.9。通过适当设计扩散屏障，可以在超过 15 分钟的时间内保持中性和酸性 pH 细胞之间的 pH 值对比。
