Microchip Capillary Electrophoresis with Electrochemical Detection

• Published in: Analytical chemistry (Washington) 2002-05, Vol.74 (10), p.2441-2445
• Main Authors: Zeng, Yong, Chen, Hong, Pang, Dai-Wen, Wang, Zong-Li, Cheng, Jie-Ke
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Analytical, structural and metabolic biochemistry; Biogenic Amines - analysis; Biological and medical sciences; Chemistry; Chromatographic methods and physical methods associated with chromatography; Disposable Equipment; Dopamine - analysis; Electrochemistry; Electrodes; Electrophoresis, Capillary - instrumentation; Electrophoresis, Capillary - standards; Epinephrine - analysis; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Microelectrodes; Miniaturization; Non peptidic neurotransmitters, polyamines; Other biological molecules; Other chromatographic methods; Reproducibility of Results; Sensitivity and Specificity; Serotonin - analysis
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac0110247

A novel microchip capillary electrophoresis system with electrochemical detection, using the replaceable microelectrode, is first reported. This kind of electrode can be fabricated in general laboratories and can be replaced quickly with electrodes of different materials according to the requirements of experiments. The end-column electrochemical detection on microchip CE was achieved by fixing the working electrode (such as carbon fiber, Pt, or Au, etc.) through a guide tube on the end of the separation channel. The experiment results indicate that the alignment of the electrode with the channel outlet can be carried out accurately and reproducibly, and therefore, the detection device has low noise and good reproducibility. The detection limit of dopamine is 2.4 × 10-7 M, which is the lowest result reported so far. The separation and detection of dopamine, 5-hydroxytryptamine and epinephrine using carbon fiber and Pt microdisk electrodes within 50 s was successfully performed.