PhD, University of Cincinnati, 2022, Arts and Sciences: Chemistry

Electrochemical aptamer-based (E-AB) sensors are a class of biosensors that employ single-stranded DNA or RNA oligonucleotides as recognition elements. Signal transduction for this class of sensor relies on a conformation change of these aptamers in the presence of a target that alters the collisional frequency of a 3'-redox reporter. The E-AB sensor platform employing the tethered modified oligonucleotide affords dynamic measurements of analytes of interest that can be used for innovative, relevant detection of analytes. As such, electrochemical biosensors that employ oligonucleotides as recognition elements, require integration into other sensing platforms like microfluidics to exploit the dynamic, reagentless measurements afforded by this class of sensors, further optimization of the sensor in changing temperatures, and applications of the sensors in a useful way which will allow them to transcend from the lab to point-of-care (POC) or medical diagnostics. This dissertation describes several ways in which the dynamic measurements of these sensors can be used to help them transcend from the lab to POC or medical diagnostics. The integration of this class of sensors into a microfluidic device using 3D printing to make microfluidic molds affords rapid prototyping of different microfluidic architectures, coupled with epoxy-embedded electrodes that use a three-electrode setup, and fabricating E-AB sensors under flow conditions to exploit the dynamic measurements afforded by E-AB sensors. Additionally, E-AB sensor signaling was characterized at different temperatures to better understand how temperature changes affect sensor response. The sensors were interrogated in the absence of and with target analyte within a temperature window of 1°C to 37°C. The chapter looks into how temperature affects sensor signaling, signal polarity, and binding affinity within the chosen temperature range. Finally, the last half of this dissertation demonstrates the capability of a (open full item for complete abstract)

Committee: Ryan White Ph.D. (Committee Member); Ashley Ross Ph.D. (Committee Member); Elke Buschbeck Ph.D. (Committee Member); Noe Alvarez Ph.D. (Committee Member) Subjects: Chemistry