Integrated electrochemical detection for lab on a chip analytical microsystems

The purpose of this study is to develop a portable capillary electrophoresis (CE) “lab-on-a-chip” device that is integrated with on-chip separation and electrochemical detection (ECD) electrodes. Platinum electrodes were photolithographically patterned on soda lime glass substrates and 20 μm by 80 μm channels were constructed within a second soda lime glass substrate. To fully realize the portability offered by this microfabricated device, a handheld battery powered CE/ECD circuit was also developed. Experimental flow visualization and computer simulation studies were performed to investigate electrokinetic flow within the microfabricated capillaries. CE/ECD “lab-on-a-chip” devices were successfully fabricated. These devices produced identical electrochemical responses for dopamine and catechol with both the portable electronics and conventional bench top power supply and detection equipment. Finally, the computer simulation results were within 10% of the experimental flow visualization results for injection and separation of dichlorofluoroscein