Positive effects of ATP on G-quadruplex-hemin DNAzyme-mediated reactions.

Some G-quadruplex-hemin complexes can be used as peroxidase-mimicking DNAzymes, catalyzing H(2)O(2)-mediated reactions such as the oxidation of 2,2'-azinobis (3-ethylbenzothiozoline)-6-sulfonic acid (ABTS) by H(2)O(2). However, some challenges, for example, the relatively low catalytic activity and the disproportionation of the reaction product ABTS*(+), may seriously restrict further development and applications of these complexes. Here, we demonstrated the positive effect of adenosine triphosphate (ATP) on G-quadruplex-hemin DNAzyme-mediated catalytic reactions. The presence of ATP not only improved the catalytic activity of G-quadruplex-hemin DNAzymes, but also inhibited the disproportionation of ABTS*(+). These observations may improve the performance of existing G-quadruplex-hemin DNAzyme-based chemical sensors, for example, the Ag(+)-detection method that uses G-quadruplex-hemin DNAzymes, and widen the application range of G-quadruplex-hemin DNAzymes. We also demonstrated that the phosphate groups, nucleobase, and sugar of ATP determine the reaction-promoting ability of ATP. These observations may be helpful in the design of highly efficient enhancers for G-quadruplex-hemin DNAzymes.