Gaudry Adam J, Breadmore Michael C, Guijt Rosanne M
Australian Centre for Research on Separation Science (ACROSS), School of Chemistry, Faculty of Science Engineering and Technology, University of Tasmania, Hobart, Tasmania, Australia.
Electrophoresis. 2013 Nov;34(20-21):2980-7. doi: 10.1002/elps.201300256. Epub 2013 Oct 1.
A simple method for producing PMMA electrophoresis microchips with in-plane electrodes for capacitively coupled contactless conductivity detection is presented. One PMMA plate (channel plate) is embossed with the microfluidic and electrode channels and lamination bonded to a blank PMMA cover plate of equal dimensions. To incorporate the electrodes, the bonded chip is heated to 80 °C, above the melting point of the alloy (≈ 70 °C) and below the glass transition temperature of the PMMA (≈ 105 °C), and the molten alloy drawn into the electrode channels with a syringe before being allowed to cool and harden. A 0.5 mm diameter stainless steel pin is then inserted into the alloy filled reservoirs of the electrode channels to provide external connection to the capacitively coupled contactless conductivity detection detector electronics. This advance provides for a quick and simple manufacturing process and negates the need for integrating electrodes using costly and time-consuming thin film deposition methods. No additional detector cell mounting structures were required and connection to the external signal processing electronics was achieved by simply slipping commercially available shielded adaptors over the pins. With a non-optimised electrode arrangement consisting of a 1 mm detector gap and 100 μm insulating distance, rapid separations of ammonium, sodium and lithium (<22 s) yielded LODs of approximately 1.5-3.5 ppm.
介绍了一种制造带有平面电极的聚甲基丙烯酸甲酯（PMMA）电泳微芯片的简单方法，用于电容耦合非接触式电导检测。一块PMMA板（通道板）被压印上微流体通道和电极通道，并与尺寸相同的空白PMMA盖板层压粘合。为了集成电极，将粘合好的芯片加热到80°C，高于合金的熔点（约70°C）且低于PMMA的玻璃化转变温度（约105°C），然后用注射器将熔融合金吸入电极通道，再让其冷却硬化。接着将一根直径0.5毫米的不锈钢针插入电极通道中填充了合金的储液器，以实现与电容耦合非接触式电导检测探测器电子设备的外部连接。这一进展提供了一种快速且简单的制造工艺，无需使用昂贵且耗时的薄膜沉积方法来集成电极。不需要额外的探测器单元安装结构，通过简单地将市售屏蔽适配器套在针上即可实现与外部信号处理电子设备的连接。采用由1毫米检测间隙和100微米绝缘距离组成的非优化电极布置，铵、钠和锂的快速分离（<22秒）产生的检测限约为1.5 - 3.5 ppm。
