The development of a separation-based sensor for catecholamines based on microdialysis (MD) coupled to microchip electrophoresis (ME) with electrochemical (EC) detection is described. The device consists of a pyrolyzed photoresist film working electrode and a poly(dimethylsiloxane) microchip with a flow-gated sample injection interface. The chip was partially reversibly sealed to the glass substrate by selectively exposing only the top section of the chip to plasma. This partially reversible chip/electrode integration process not only allows the reuse of the working electrode but also greatly enhanced the reproducibility of electrode alignment with the separation channel. The developed MD-ME-EC system was then tested using l-DOPA, 3-O-MD, HVA, DOPAC, and dopamine standards, which were separated in less than 100 seconds using a background electrolyte consisting of 15 mM sodium phosphate (pH 7.4), 15 mM sodium dodecyl sulfate, and 2.5 mM boric acid. A potential of +1.0 V vs. Ag/AgCl was used for amperometric detection of the analytes. The device was evaluated for on-line monitoring of the conversion of l-DOPA to dopamine in vitro and for monitoring dopamine release in an anesthetized rat in vivo following high K+ stimulation. The system was able to detect stimulated dopamine release in vivo but not endogenous levels of dopamine.

中文翻译：

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具有电化学检测的儿茶酚胺在线体内监测的基于微芯片电泳分离的传感器的开发进展。

描述了基于微透析（MD）耦合基于微芯片电泳（ME）和电化学（EC）检测的基于儿茶酚胺的基于分离的传感器的开发。该设备由热解光致抗蚀剂薄膜工作电极和带有流动门控样品注入接口的聚二甲基硅氧烷微芯片组成。通过选择性地仅将芯片的顶部部分暴露于等离子体，将芯片部分可逆地密封到玻璃基板上。这种部分可逆的芯片/电极集成过程不仅允许工作电极的重复使用，而且还大大增强了电极与分离通道对准的可重复性。然后使用l-DOPA，3-O-MD，HVA，DOPAC和多巴胺标准品对开发的MD-ME-EC系统进行测试，使用由15 mM磷酸钠（pH 7.4），15 mM十二烷基硫酸钠和2.5 mM硼酸组成的背景电解质在不到100秒的时间内将其分离。相对于Ag / AgCl的+1.0 V电位用于分析物的安培检测。评估该设备用于在线监测体外I-DOPA向多巴胺的转化，以及监测高K +刺激后体内麻醉的大鼠中多巴胺的释放。该系统能够检测体内刺激的多巴胺释放，但不能检测内源性多巴胺水平。评估该设备用于在线监测体外I-DOPA向多巴胺的转化，以及监测高K +刺激后体内麻醉的大鼠中多巴胺的释放。该系统能够检测体内刺激的多巴胺释放，但不能检测内源性多巴胺水平。评估该装置用于在线监测1-DOPA在体外对多巴胺的转化，以及在高K +刺激后在体内监测麻醉大鼠体内多巴胺的释放。该系统能够检测体内刺激的多巴胺释放，但不能检测内源性多巴胺水平。