Development of a microfabricated disposable microchip with a capillary electrophoresis and integrated three-electrode electrochemical detection.

We have developed microsystems with a capillary electrophoresis and an electrochemical detector. 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 (PDMS)-glass chip and an indium tin oxide electrode. The injection and separation channels were produced by relatively simple and inexpensive methods. A capillary electrophoresis and a three-electrode electrochemical detector were fabricated on the same substrate with the same fabrication procedure. We measured electropherograms for the testing analytes consisting of catechol and dopamine with different concentrations of 1mM and 0.1mM, respectively. The results showed an efficient and rapid separation and detection of all compounds within a very short time of around 80s using a separate electric field 60 V/cm. We could also successfully achieve an electropherogram of the separation of the 1 kb DNA ladder (8.4 ng/mul) from the 500 bp to 10 kb DNA fragments within just 150 s.