Aptasensor Development For Biomarker Detection Using Fluorescent Guanine Quadruplexes
Aptamers are nucleic acids that are found to bind molecular targets with a high degree of specificity and affinity. Guanine (G) rich aptamers are known to fold into G quadruplex structures (GQ). The synthesis of fluorescently modified guanine probes, 8-(4ʹʹ-acetylstyryl)-2ʹ-dG (AcVdG) and 8-((2-benzo[b]thiophen-2-yl)vinyl)-2ʹ-dG VBTdG, are presented in this thesis. The synthesized 8-vinyl-aryl-probes were incorporated into the TBA using solid phase oligonucleotide synthesis. Their impact on DNA structures were explored as was the ability of the probes to be used for the fluorescent detection of Pb2+, Sr2+, and Ba2+. Furthermore, to utilize the benefits of 8-aryl-dG and 8-vinyl-aryl-dG probes, both were incorporated into the TBA. The two probes act as Fluorescent Resonance Energy Transfer (FRET) pairs; one was used as the “switch” in the system, sensitively detecting GQ folding, whiles the other acts as “the signal” or “light” producing a detectable signal in the visible region.