On Chip Preconcentration and Labeling of Protein Biomarkers Using Monolithic Columns, Device Fabrication, Optimization, and Automation

• Main Author: Yang, Rui
• Format: Others
• Published: BYU ScholarsArchive 2014
• Subjects: Microfluidics; Solid-phase extraction; Monolith; Preconcentration; On-chip labeling; Biochemistry; Chemistry
• Online Access: https://scholarsarchive.byu.edu/etd/4360; https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=5359&context=etd

Detection of disease specific biomarkers is of great importance in diagnosis and treatment of diseases. Modern bioanalytical techniques, such as liquid chromatography with mass spectrometry (LC-MS), have the ability to identify biomarkers, but their cost and scalability are two main drawbacks. Enzyme-linked immunosorbent assay (ELISA) is another potential tool, but it works best for proteins, rather than peptide biomarkers. Recently, microfluidics has emerged as a promising technique due to its small fluid volume consumption, rapidness, low fabrication cost, portability and versatility. Therefore, it shows prominent potential in the analysis of disease specific biomarkers. In this thesis, microfluidic systems that integrate monolith columns for preconcentration and on-chip labeling are developed to analyze several protein biomarkers. I have successfully fabricated cyclic olefin copolymer (COC) microfluidic devices with standard micromachining techniques. Monoliths are prepared in situ in microchannels via photopolymerization, and the physical properties of monoliths are optimized by varying the composition and concentration of monomers to achieve better flow and extraction. On-chip labeling of protein biomarkers is achieved by driving solution through the monolith using voltage and incubating fluorescent dye with protein retained in the monolith. Subsequently, the labeled proteins are eluted by applying voltages to reservoirs on the microdevice and detected by laser-induced fluorescence. Finally, automation of on-chip preconcentration and labeling is successfully demonstrated.