General Sensor Design Strategy Based on G-Quadruplex-Hemin DNAzymes

Some G-quadruplex-hemin complexes can be used as a type of DNAzymes with peroxidase activity, it can efficiently catalyze H2O2-mediated oxidation reactions. Herein, a simple, colorimetric, and homogenous sensor design strategy based on G-quadruplex-hemin DNAzymes was developed. This strategy takes advantages of the competition between a DNA/DNA duplex and a DNA/target complex, and the formation of catalytically active G-quadruplexes in the presence of targets. With this method, no labeled oligonucleotides are needed, and no expensive instruments are required. This strategy may be developed as a general approach for the analysis of many metal ions and aptamer substrates. In this paper, the feasibility of this strategy in Hg2+ and adenosine triphosphate (ATP) detection was studied, and results showed that this “turn-on” process enabled the selective detection of aqueous Hg2+ and adenosine triphosphate (ATP) using a simple colorimetric technique.