Dual capillary electrophoresis devices with electrochemical detection on a single platform

The purpose of this paper is to demonstrate the feasibility of developing a single lab-on-a-chip (LOC) platform capable of performing dual, simultaneous separation and detection of multiple analytes. Computational modeling was performed to determine optimum device geometry and performance. The soda-lime glass-based device was fabricated using traditional microtechnology processes, including UV photolithography, buffered oxide etch (BOE), electrode deposition and compression thermal bonding. The device was characterized with a mixture of dopamine (2mM) and catechol (2mM) in a phosphate buffer (20mM, 6.5 pH). Modeling results yielded migration velocities of 0.6 mm/s and 0.42 mm/s for dopamine (electrokinetic (EK) mobility=60,000 μm²/V·s) and catechol (EK mobility=42,000 μm²/V·s), respectively. Experimental results obtained from microchips exhibiting the same EK mobilities demonstrated identical electropherograms in both detection channels with migration velocities of 0.58 mm/s for dopamine and 0.41 mm/s for catechol.