A disposable capillary electrophoresis microchip with an indium tin oxide decoupler/amperometric detector

We have fabricated a capillary electrophoresis (CE) chip-based electrochemical detection (ECD) system for measurements of the dopamine, catechol, DNA ladder, and hydrogen peroxide, respectively. The microfabricated CE-ECD systems are adequate for a disposable type and the characteristics are optimized for application in electrochemical detection. The system was realized by means of a polydimethylsiloxane-glass chip and an indium tin oxide electrode. The CE-ECD system has been fabricated with relatively simple and inexpensive methods. A capillary electrophoresis and a three-electrode electrochemical detector were fabricated on the same chip. The decoupler could mostly decouple the electrochemical detection circuit from the interference of a separation electric field. Measuring dopamine, catechol, DNA ladder, and hydrogen peroxide, respectively, was successful with a microchip. All oxidizable species could be detected in less 150 s. Disposable CE-chips make it possible to avoid polishing and reconditioning, which are required with gold CE-chips.