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Full-Text Articles in Physical Sciences and Mathematics
Simple, Label-Free And Non-Instrumented Analyte Quantitation By Flow Distance Measurement In Microfluidic Devices, Debolina Chatterjee
Simple, Label-Free And Non-Instrumented Analyte Quantitation By Flow Distance Measurement In Microfluidic Devices, Debolina Chatterjee
Theses and Dissertations
Rapid determination of the concentrations of molecules related to diseases can provide timely information for treatment options. However, most biomarker quantitation methods require costly and complex equipment. On the other hand, point-of-care systems have less complex instrumentation needs than laboratory-based equipment, but often provide less information; for example, biomarker presence or absence instead of concentration. A complete analysis setup addressing key limitations of both laboratory-based and portable systems is highly desirable. I developed microfluidic devices with visual inspection readout of a target’s concentration from microliter volumes of solution flowed into a microchannel. Microchannels are formed within polydimethylsiloxane (PDMS), and the …
Identification And Differentiation Of Tier 1 Bacterial Agents Using Gas Chromatography-Mass Spectrometry, Dan Li
Theses and Dissertations
A simple method was developed for detection and differentiation of five Tier 1 bacterial agents, including Bacillus anthracis, Francisella tularensis, Yersinia pestis, Burkholderia pseudomallei and Burkholderia mallei as well as their closely related near neighbors by gas chromatography-mass spectrometry (GC-MS). Generally, different classes of compounds can be used as biomarkers for biowarfare agent detection, including nucleic acids (i.e., DNA or RNA), proteins (i.e., antibodies), carbohydrates (i.e., sugars), lipopolysaccharides, lipids (i.e., fatty acids) and small molecules. One-step thermochemolysis (TCM) was developed to provide GC-MS detectable biomarker signatures, including sugars, fatty acids and small molecules. Solid phase micro-extraction (SPME) was used for …
Microfluidic Devices With Integrated Sample Preparation For Improved Analysis Of Protein Biomarkers, Pamela Nsang Nge
Microfluidic Devices With Integrated Sample Preparation For Improved Analysis Of Protein Biomarkers, Pamela Nsang Nge
Theses and Dissertations
Biomarkers present a non-invasive means of detecting cancer because they can be obtained from body fluids. They can also be used for prognosis and assessing response to treatment. To limit interferences it is essential to pretreat biological samples before analysis. Sample preparation methods include extraction of analyte from an unsuitable matrix, purification, concentration or dilution and labeling. The many advantages offered by microfluidics include portability, speed, automation and integration. Because of the difficulties encountered in integrating this step in microfluidic devices most sample preparation methods are often carried out off-chip. In the fabrication of micro-total analysis systems it is important …
Integrated Affinity Column Capillary Electrophoresis Microdevices For Biomarker Analysis, Weichun Yang
Integrated Affinity Column Capillary Electrophoresis Microdevices For Biomarker Analysis, Weichun Yang
Theses and Dissertations
In this dissertation, microfluidic systems that integrate antibody-based sample preparation methods with electrophoretic separation are developed to analyze multiple biomarkers in a point-of-care setting. To form an affinity column, both monolith materials and wall-coated channels were explored. I successfully demonstrated that monolith columns can be prepared in microfluidic devices via photopolymerization. The selectivity of monolith columns was improved by immobilizing antibodies on the surface. These affinity columns can selectively enrich target analytes and reduce the signal of contaminant proteins up to 25,000 fold after immunoaffinity extraction. These results clearly demonstrate that microchip affinity monoliths can selectively concentrate and purify target …