State Key Lab of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, P. R. China.
Electrophoresis. 2011 Mar;32(6-7):699-704. doi: 10.1002/elps.201000562. Epub 2011 Feb 22.
A contactless conductivity detector integrated into a poly(dimethylsiloxane) microchip for electrophoresis is presented. It adopted the simplest configuration of electrodes commonly used in this detection mode for capillary electrophoresis microchips. Although the chip is based on a simple and effective design, it is able to obtain low detection levels due to the low noise of the detection circuit. A circuit based on a lock-in amplifier was designed on printed circuit boards to read out the signal. The property of the detection cell was studied by applying excitation signals of different frequencies and different amplitudes. It was found that the best detection limit could be achieved with a frequency of 50 kHz and amplitude of 20 V. The performance of the detector was demonstrated by successfully separating and detecting several inorganic ions and also a mixture of heavy metal ions. An average detection limit of 0.4 μM was obtained for inorganic cations. This value is significantly improved compared to similar microchip-based detectors. The presented detector could be promising for mass production due to its properties, such as simple construction, high degree of integration, high performance and low cost.
提出了一种集成在聚二甲基硅氧烷微芯片中的无接触电导检测器，用于电泳。它采用了毛细管电泳微芯片中这种检测模式常用的电极的最简单配置。尽管该芯片基于简单有效的设计，但由于检测电路的低噪声，能够获得低检测水平。设计了基于锁相放大器的印刷电路板电路来读取信号。通过施加不同频率和不同幅度的激励信号来研究检测池的性能。结果发现，在频率为 50 kHz、幅度为 20 V 时，可以获得最佳的检测极限。通过成功分离和检测几种无机离子和重金属离子混合物，证明了该检测器的性能。对于无机阳离子，获得了 0.4 μM 的平均检测限。与类似的基于微芯片的检测器相比，该值有了显著提高。由于其结构简单、集成度高、性能高、成本低等特点，该检测器有望实现大规模生产。
