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Bipolar Electrode Focusing: The Effect Of Current And Electric Field On Concentration Enrichment, Robbyn K. Perdue, Derek R. Laws, Dzmitry Hlushkou, Ulrich Tallarek, Richard M. Crooks
Bipolar Electrode Focusing: The Effect Of Current And Electric Field On Concentration Enrichment, Robbyn K. Perdue, Derek R. Laws, Dzmitry Hlushkou, Ulrich Tallarek, Richard M. Crooks
Robbyn Anand
Bipolar electrode focusing at discontinuous bipolar electrodes (BPEs) provides new insight into the faradaic current and electric field characteristics associated with the technique and allows for the controlled transport of a focused anionic tracer in a microfluidic channel. The findings corroborate our previously reported simulation results, which describe the formation of an extended electric field gradient leading to concentration enrichment. This gradient has been attributed to the passage of faradaic current through a BPE affixed to the floor of the microchannel. Our results demonstrate that the onset of faradaic current is coincident with the onset of concentration enrichment. Utilizing an …
Bipolar Electrode Focusing: Simultaneous Concentration Enrichment And Separation In A Microfluidic Channel Containing A Bipolar Electrode, Derek R. Laws, Dzmitry Hlushkou, Robbyn K. Perdue, Ulrich Tallarek, Richard M. Crooks
Bipolar Electrode Focusing: Simultaneous Concentration Enrichment And Separation In A Microfluidic Channel Containing A Bipolar Electrode, Derek R. Laws, Dzmitry Hlushkou, Robbyn K. Perdue, Ulrich Tallarek, Richard M. Crooks
Robbyn Anand
A method for simultaneously concentrating and separating analytes in a buffer-filled microfluidic channel is reported. The approach is based on modulation of the local electric field within the channel and the corresponding opposition of electrophoretic and electroosmotic flow (EOF) velocities. Dye molecules having different electrophoretic mobilities are focused at different locations within the channel where concentration takes place. At least three species, all small dye molecules, can be simultaneously concentrated and separated, with localized enrichment factors up to ∼600 achieved within 400 s. The enrichment zones affect the electric field profile, as evidenced by significant differences in focusing of single …