CONCENTRATION ENHANCEMENT AND DEVICE FABRICATION FOR THE IMPROVED PERFORMANCE OF GRADIENT ELUTION MOVING BOUNDARY ELECTROPHORESIS

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dc.contributor.advisorFourkas, John ten_US
dc.contributor.authorSikorsky, Alison Anneen_US
dc.contributor.departmentChemistryen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2014-10-11T05:59:55Z
dc.date.available2014-10-11T05:59:55Z
dc.date.issued2014en_US
dc.description.abstractMany recent efforts in the field of microfluidics have been focused on reducing the size and the complexity of devices and on simplifying the methods of analysis performed with them. Gradient elution moving boundary electrophoresis (GEMBE) is a recently described counterflow electrophoresis method that was developed to simplify the analysis of ions in complex matrices. In this thesis, the improvement of the limit of detection of GEMBE and reduction of the GEMBE channel length is investigated. Integration of simple and robust device components required for the successful adaptation of many analytical methods to multiplexed and field-portable devices often has negative effects on detection sensitivity, such as in the optical detection components in a capillary electrophoresis (CE) system. One of the simplest methods to improve sensitivity in the CE field is known as sample stacking. This method involves preparing the sample in a buffer with a different concentration (and conductivity) than that of the run buffer, such that when an electric field is applied the analyte concentration is increased at the boundary between the two different buffer concentrations. A method in which the sample is prepared in a buffer at a lower concentration than the run buffer has been implemented. This method achieves a significantly greater signal enhancement than expected for sample stacking. The concentration enhancement ability of this method is demonstrated utilizing GEMBE with channel current detection. Current GEMBE device construction methods impose limitations on the minimum length of the separation channel. One technique well suited for minimizing the size of the GEMBE separation channel is multiphoton absorption polymerization (MAP). Because MAP is a non-linear optical fabrication method, polymerization is limited to a small region near the focal point of a laser beam. As a result, three-dimensional structures with small feature sizes can be easily created. The 3D capabilities of MAP have been exploited to create channels with circular cross sections and ~300 μm lengths for GEMBE. The integration of device components fabricated with MAP and molded with PMDS allows visualization of the GEMBE separations, and provides insights into the effect of channel length on GEMBE step width.en_US
dc.identifierhttps://doi.org/10.13016/M26G6M
dc.identifier.urihttp://hdl.handle.net/1903/15832
dc.language.isoenen_US
dc.subject.pqcontrolledChemistryen_US
dc.subject.pquncontrolledelectrophoresisen_US
dc.subject.pquncontrolledfabricationen_US
dc.subject.pquncontrolledgradient elutionen_US
dc.subject.pquncontrolledMicrofluidicsen_US
dc.subject.pquncontrolledMultiphotonen_US
dc.subject.pquncontrolledStackingen_US
dc.titleCONCENTRATION ENHANCEMENT AND DEVICE FABRICATION FOR THE IMPROVED PERFORMANCE OF GRADIENT ELUTION MOVING BOUNDARY ELECTROPHORESISen_US
dc.typeDissertationen_US

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