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 1 mM and 0.1 mM, respectively. The results showed an efficient and rapid separation and detection of all compounds within a very short time of around 80 s 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/μl) from the 500 bp to 10 kb DNA fragments within just 150 s.