We present the design and characterization of a low cost, thread-based electrophoretic device with integrated electrochemical detection. The device has an end-channel pencil graphite electrode placement system for performing electrochemical detection on the thread electrophoresis platform with direct sample pipetting onto the thread. We also established the use of methylene blue and neutral red as a pair of reference migration markers for separation techniques coupled with electrochemical detection, as they have different colors for visual analysis and are both electroactive. Importantly, neutral red was also found to migrate at a similar rate to the EOF, indicating that it can be used as a visual identifier of EOF. The utility of our system was demonstrated by electrophoretic separation and electrochemical detection of physiologically relevant concentrations of pyocyanin in a solution containing multiple electroactive compounds. Pyocyanin is a biomarker for the detection of pathogenic Pseudomonas aeruginosa and has a redox potential that is similar to that of methylene blue. The system was able to effectively resolve methylene blue, neutral red, and pyocyanin in less than 7 min of electrophoretic separation. The theoretical limit of detection for pyocyanin was determined to be 559 nM. The electrophoretic mobilities of methylene blue (0.0236 ± 0.0007 mm²/V·s), neutral red (0.0149 ± 0.0007 mm²/V·s), and pyocyanin (0.0107 ± 0.0003 mm²/V·s) were also determined.

中文翻译：

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与末端通道铅笔电极检测器耦合的聚酯线电泳

我们介绍了一种具有集成电化学检测功能的低成本、基于螺纹的电泳装置的设计和表征。该设备有一个末端通道铅笔石墨电极放置系统，用于在螺纹电泳平台上进行电化学检测，直接将样品移液到螺纹上。我们还建立了使用亚甲蓝和中性红作为一对参考迁移标记物，用于结合电化学检测的分离技术，因为它们具有不同的颜色用于视觉分析并且都具有电活性。重要的是，还发现中性红以与 EOF 相似的速率迁移，表明它可以用作 EOF 的视觉标识符。我们系统的实用性通过电泳分离和电化学检测生理相关浓度的绿脓素在含有多种电活性化合物的溶液中得到证实。绿脓杆菌素是检测致病菌的生物标志物铜绿假单胞菌具有与亚甲蓝相似的氧化还原电位。该系统能够在不到 7 分钟的电泳分离时间内有效分离亚甲蓝、中性红和绿脓素。绿脓素的理论检测限确定为 559 nM。还测定了亚甲蓝 (0.0236 ± 0.0007 mm ² /V·s)、中性红 (0.0149 ± 0.0007 mm ² /V·s) 和绿脓素 (0.0107 ± 0.0003 mm ² /V·s) 的电泳迁移率。