Fabrication and evaluation of a carbon‐based dual‐electrode detector for poly(dimethylsiloxane) electrophoresis chips

The first carbon‐based dual‐electrode detector for microchip capillary electrophoresis (CE) is described. The poly(dimethylsiloxane) (PDMS)‐based microchip CE devices were constructed by reversibly sealing a PDMS layer containing separation and injection channels to another PDMS layer containing carbon fiber working electrodes. End‐channel amperometric detection was employed and the performance of the chip was evaluated using catechol. The response was found to be linear between 1 and 600 μM with an experimentally determined limit of detection (LOD) of 500 nM and a sensitivity of 30 pA/μM. Collection efficiencies for catechol ranged from 36.0 to 43.7% at field strengths of 260—615 V/cm. The selectivity that can be gained with these devices is demonstrated by the first CE‐based dual‐electrode detection of a Cu(II) peptide complex. These devices illustrate the potential for a rugged and easily constructed microchip CE system with an integrated carbon‐based detector of similar scale.

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