Development of disposable lab-on-a-chip system for point-of-care-testing
Date of Issue2017
School of Mechanical and Aerospace Engineering
With the steady growth in microfluidic technologies, substantial advance in Lab-on-a- Chip system has been observed, which enables miniaturization and integration of complex functions that had been routinely performed by hand in the traditional analytical processes into micro-scale small devices. One of the most active applications of these technologies is Point-of-care (POC) diagnostic device that can rapidly deliver the diagnostic outcomes to patients. POC diagnostic system provides the users with many benefits over the traditional diagnostic methods such as straightforward and easy-to-use interface, portability, less sample and reagent consumption, etc. This thesis presents novel microfluidic LOC techniques which are potentially suitable for POC diagnostic testing. Of the three technologies described in this thesis, the first two of LOC methods are to address current issues regarding nucleic acid analysis in POC testing. The first is LOC system for the detection of DNA methylation by combining on-chip bisulfite conversion and detection on a silicon biophotonic sensor. By performing bisulfite conversion reaction, an essential sample processing step in DNA methylation detection, within the microfluidic platform, it was able to overcome limitations that existing DNA methylation methods are facing, such as DNA degradation, long sample processing time, low amplification efficiency, etc. This novel method has great potential as a useful tool in epigenetic biomarker studies for both research and clinical use. The second approach is LOC system for RNA isolation. High-quality, intact RNA from various biological samples can be isolated within the disposable microfluidic platform for downstream diagnostic analysis with reduced time and minimal hands-on processes. Gene expression studies, as well as detection of infectious disease, were performed using the isolated RNA from LOC system to show the feasibility of proof-of-concept. This novel microfluidic approach offers a new paradigm of RNA isolation that can be potentially used in many diagnostic applications at point of care. The last LOC technique described here is to enhance nanoscale biomolecule separation by integrating dead-end filtration and ultrasonic treatment into small-scale microfluidic platform which aims to perform particle separation as a preparative process in POC diagnostic testing. The functionality of this novel LOC based technology was confirmed by demonstrating size based gold and polymer nanoparticle separation.