DEVELOPMENT OF A MICROSCALE ELECTROCHEMICAL PLATFORM FOR THE ANALYSIS OF THERMAL PROFILES OF IMMOBILIZED DNA SECONDARY STRUCTURES
Lee, Sang Bok
MetadataShow full item record
Understanding the thermal stability of DNA secondary structures is important to the pharmaceutical industry, as drug molecules that strongly bind will increase the stability of the structure, leading to higher measured melting temperatures. Development of an electronic platform that can measure the thermal profiles of small-volume samples with automation and methodology that is scalable for high-throughput screening (HTS) would represent an important asset for the drug discovery process. This thesis endeavored to produce and demonstrate the feasibility of such a technology. A microelectronic device has been fabricated in the configuration of a planar electrochemical platform with an embedded platinum thin film that can function as both a platinum resistance thermometer (PRT) and as a resistive microheater. The device assembly as well as automation of the temperature control and electrochemical methods have been instituted to increase measurement repeatability with the microscale device. The operational program was developed with a variety of features, including a PID controller, and has been demonstrated for a two-device array; functioning is scalable to larger device arrays with the addition of suitable electronics. A proof-of-concept methodology has been shown for monitoring the stabilization effects of ligand binding to duplex DNA. Results are presented for both refrigeration with resistive heating, and thermoelectric cooling and heating. The technology has also been adapted to examine other DNA secondary structures, such as G-quadruplexes, and the stabilization of these structures. The resulting analysis of such immobilized intramolecular secondary structures has demonstrated that the systems are more complicated and further fundamental studies are needed. With the future incorporation of microfluidics and larger-device arrays, a range of effects can be tested based on the demonstrated technology to understand binding events of relevance to drug discovery and the complexities of the surface chemistry effects on the analysis of thermal profiles.