The Effect of Carbon Nanotube on Improving Catalytic G-quadruplex Sensing Properties

In the use of G-quadruplex as DNAzyme, the background signal corresponding to Hemin is high. Therefore, it limits the application of DNAzyme. If carbon nanotubes are added to the system containing G-quadruplex and Hemin, this problem will be solved. However, the mechanism of the nanotube effect on DNAzyme is not known. In this work, molecular dynamics simulation was used to clarify this mechanism. The interaction between G-quadruplex and Hemin was simulated in the presence and absence of carbon nanotubes. The calculated distance between the center of mass of G-quadruplex and Hemin during the simulation time shows that the nanotube increases the affinity of hemin to G-quadruplex. Also, the calculation of the conformational factor of the G-quadruplex residues shows that Hemin is bonded to the G-quadruplex from the top and side. The obtained results are in good agreement with the available experimental evidence.