Poly(3,4-ethylenedioxythiophene)-Modified Electrodes for Microfluidics Pumping with Redox-Magnetohydrodynamics: Improving Compatibility for Broader Applications by Eliminating Addition of Redox Species to Solution
Poly(3,4-ethylenedioxythiophene)-Modified Electrodes for Microfluidics Pumping with Redox-Magnetohydrodynamics: Improving Compatibility for Broader Applications by Eliminating Addition of Redox Species to Solution
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DOI：
10.1021/acs.analchem.5b03182
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发表时间：
2016-02-02
影响因子：
7.4
通讯作者：
Fritsch, Ingrid
中科院分区：
文献类型：
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作者：
Nash, Christena K.;Fritsch, Ingrid
采用聚（3,4-乙撑二氧噻吩）（PEDOT）修饰的电极的新方法用于执行氧化还原磁流体动力学（MHD）微流体，并且无需向溶液中添加氧化还原物质。从而消除对芯片实验室应用的检测、样品和试剂的干扰。这一成就不仅保留了氧化还原 MHD 泵送的独特特性（即可编程流体速度和流动模式，无需侧壁、水平平坦流动剖面、循环流动、无电极腐蚀、无气泡形成），而且实现了更宽的可持续电压范围和电流，比过去涉及未修饰电极和溶液中氧化还原物质的研究高出 7 倍以上（因此相应地更高的速度）。 PEDOT 是一种具有低细胞毒性的导电聚合物，在微带金电极（25 毫米长 x 103 微米宽）上进行电聚合。通过将620μm厚的聚(二甲基硅氧烷)、PDMS、具有3.2cm×1.5cm开口的垫圈放置在芯片上形成具有较远侧壁的细胞(325μL)，并且载玻片盖防止蒸发。芯片下方的 0.37 T 磁体产生垂直于芯片表面的磁场。该池充满了含有 10 μm 聚苯乙烯珠的 0.095 M NaCl 电解质，以便使用光学视频显微镜可视化和量化流体流动。施加电位步骤后立即观察到流体速度为 590 μ m s(-1)。显示了施加的电子电流和流体速度之间的线性关系。应用电流条件下的垂直流动剖面是弯曲的，具有弱抛物线拟合。
A new approach using electrodes modified with poly(3,4-ethylenedioxythiophene) (PEDOT) was implemented to perform redox-magnetohydrodynamics (MHD) microfluidics and eliminate the need to add redox species to solution,. thus removing interferences with detection, sample, and reagents for lab-on-a-chip applications. This accomplishment not only retains the unique properties of redox-MHD pumping (i.e., programmable fluid speeds and flow patterns without the need for side walls, horizontal flat flow profiles, looping flow, no electrode corrosion, and no bubble formation), but also achieves a wider sustainable voltage range and currents that can be as much as 7+ times higher (and therefore correspondingly higher velocities) than in past studies involving unmodified electrodes and redox species in solution. PEDOT, a conducting polymer that has been shown to exhibit low cytotoxicity, was electropolymerized on microband gold electrodes (25 mm long x103 mu m wide). A cell (325 mu L) with distant side walls was formed by placing a 620 mu m thick poly(dimethylsiloxane), PDMS, gasket with an opening of 3.2 cm X 1.5 cm on the chip, and a glass slide lid prevented evaporation. A 0.37 T magnet under the chip generated a magnetic field perpendicular to the chip surface. The cell was filled with 0.095 M NaCl electrolyte containing 10 mu m polystyrene beads to visualize and quantify fluid flow using optical video microscopy. Fluid speeds of 590 mu m s(-1) were observed immediately after applying a potential step. A linear relationship between applied electronic current and fluid velocity was shown. Vertical flow profiles under applied current conditions were curved, with a weak parabolic fit.