Abstract
DNA is not just a carrier of genetic information, it is also a chemical. It is a molecule with certain properties, a specific arrangement of atoms, and a commercialized chemical synthesis pathway. DNA is widely used, manipulated, and well-studied in bioanalysis. For instance, the current diagnostic assays for the SARS-CoV-2 virus rely upon DNA-based bioanalysis. At a fundamental level, DNA-based bioanalysis takes the advantage of Watson-Creek base pairing. Adenine pairs specifically with thymine, guanidine pairs with cytidine. This pairing is cooperative and specific. DNA is held together by many weak hydrogen bonds only when sequences are complementary. Together with the advance of many detection systems, enzymes, small molecule dyes, DNA-based bioanalysis is a diverse and demanding research field in chemistry. We used these advantages to develop enzymatic and non-enzymatic reactions for cost-effective, label-free, isothermal detection. Two isothermal systems, entropy-driven amplifier (EDA) and strand displacement amplification (SDA), are developed to detect physiologically important miRNAs. This thesis includes three research chapters and one review.