DNA G-Quadruplex as a Reporter System for Sensor Development

Abstract

The versatile DNA G-quadruplex structure has emerged as an interesting alternative reporter system applied in different biosensor platforms. In comparison to the conventional reporter systems like enzymatic or fluorescent, DNA G-quadruplex has some distinct advantages, as it is thermostable, easy to produce, low cost and most importantly able to be amplified. Such remarkable advantages have led many researchers to exploit DNA Gquadruplex as the reporter system in colorimetric, fluorescence and luminescence sensors. There has also been integration of DNA G-quadruplex with electrochemical methods and quantum dot for sensing applications. Therefore, this chapter highlights some recent examples of different biosensor platforms that use DNA G-quadruplex as a reporter system with different detection methods.

Oxacillin Coupled G-Quadruplexes as a Novel Biofilm-Specific Antibiotic for Staphylococcus aureus Biofilms

“…24 Once assembled, the G4s can take on several conformations including parallel, anti-parallel and hybrid (see Figure 1(a)) and can be composed of a single DNA strand (intramolecular) or multiple DNA strands (intermolecular). 25,26 Of particular interest is that G4s are able to complex with hemin (Figure 1(b)), an iron containing protoporphyrin IX, which acquires peroxidase-mimicking activity in the presence of H2O2. 27 The hemin (FeIII) first complexes with H2O, which is then replaced with H2O2 (Figure 1(c)).…”

“…A potential method to replace the SCN-peroxidase-H 2 O 2 system is to use the peroxidase-mimicking activity of catalytic DNA molecules (DNAzymes), in particular G-quadruplexes (G4s), which provide several advantages over enzymes including cheaper synthesis and purification, wider operating conditions (pH and temperature), and the ability to react with a various substrates. , G4s are assembled from guanine-rich (G-rich) DNA sequences that can stack two or more guanine-quartets (G-quartets) (see Figure a) in the presence of a metal cation . Once assembled, the G4s can take on several conformations including parallel, antiparallel, and hybrid (see Figure a) and can be composed of a single DNA strand (intramolecular) or multiple DNA strands (intermolecular). , …”