Jiang Lei, Lu Yao, Dai Zhongpeng, Xie Minhao, Lin Bingcheng
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
Lab Chip. 2005 Sep;5(9):930-4. doi: 10.1039/b505467b. Epub 2005 Jul 13.
This paper presents the development of a mini-electrochemical detector for microchip electrophoresis. The small size (3.6 x 5.0 cm2, W x L) of the detector is compatible with the dimension of the microchip. The use of universal serial bus (USB) ports facilitates installation and use of the detector, miniaturizes the detector, and makes it ideal for lab-on-a-chip applications. A fixed 10 M ohm feedback resistance was chosen to convert current of the working electrode to voltage with second gain of 1, 2, 4, 8, 16, 32, 64 and 128 for small signal detection instead of adopting selectable feedback resistance. Special attention has been paid to the power support circuitry and printed circuit board (PCB) design in order to obtain good performance in such a miniature size. The working electrode potential could be varied over a range of +/-2.5 V with a resolution of 0.01 mV. The detection current ranges from -0.3 x 10(-7) A to 2.5 x 10(-7) A and the noise is lower than 1 pA. The analytical performance of the new system was demonstrated by the detection of epinephrine using an integrated PDMS/glass microchip with detection limit of 2.1 microM (S/N = 3).
本文介绍了一种用于微芯片电泳的微型电化学检测器的研制情况。该检测器尺寸小（3.6×5.0平方厘米，宽×长），与微芯片尺寸兼容。使用通用串行总线（USB）端口便于检测器的安装和使用，使检测器小型化，使其成为芯片实验室应用的理想选择。选择固定的10兆欧反馈电阻将工作电极的电流转换为电压，用于小信号检测时增益分别为1、2、4、8、16、32、64和128，而不是采用可选的反馈电阻。为了在如此小的尺寸下获得良好性能，特别关注了电源支持电路和印刷电路板（PCB）设计。工作电极电位可在±2.5伏范围内变化，分辨率为0.01毫伏。检测电流范围为-0.3×10⁻⁷安至2.5×10⁻⁷安，噪声低于1皮安。使用集成的聚二甲基硅氧烷/玻璃微芯片检测肾上腺素证明了新系统的分析性能，检测限为2.1微摩尔（信噪比=3）。
