Publication Date

2025

Document Type

Dissertation/Thesis

First Advisor

Nesterova, Irina V.

Degree Name

Ph.D. (Doctor of Philosophy)

Legacy Department

Department of Chemistry and Biochemistry

Abstract

The goal of our project is to develop an equipment-free signal readout platform suitable for potential molecular diagnostics applications. In the development, we adhere to (RE)ASSURED (Real time, Ease of specimen collection, Affordable, Sensitive, Specific, User-Friendly, Robust, and rapid, Equipment free, Deliverable) criteria. As a proof of concept, we focus on oligonucleotide targets. Our detection system incorporates an activatable catalytic complex that causes the decomposition of Hydrogen Peroxide (H2O2); oxygen (O2) bubbles released in reaction serve as signal readout. The catalytic system comprises of DNA G-quadruplex and Hemin. The catalytic activity and, therefore, the signal are triggered in the presence of molecular targets. While G-quadruplex enzymes are well known to mimic peroxidase activity, their catalase properties have not been explored up to date. To optimize the signal readout, we investigate a correlation between catalytic activity and topology of G-quadruplexes, pH, and the ionic composition, as those factors can play a significant role in the visualization and detection of bubbles. To recognize the target, we introduced various split forms of G-quadruplex with elongated arms that are complementary to the tested oligonucleotide target. Further, we explore ways to maximize the signal to background ratio for target recognition by modifying splitting G-quadruplexes and hemin to different DNA strands making assembly contingent on target recognition.

Extent

126 pages

Language

en

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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