Chem. J. Chinese Universities ›› 2019, Vol. 40 ›› Issue (2): 279.doi: 10.7503/cjcu20180673

• Physical Chemistry • Previous Articles     Next Articles

Theoretical Study on Enhancement Effect of Amino Modification of Adenine on Conductivity of DNA

CHENG Yingying, LIU Haiying*(), TIAN Yigeng, LIU Zhongqi, LI Qingxin   

  1. School of Physics and Technology, University of Jinan, Jinan 250022, China
  • Received:2018-10-08 Online:2019-02-10 Published:2018-11-26
  • Contact: LIU Haiying E-mail:ss_liuhy@ujn.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.21673101)

Abstract:

The effect of amino modification of adenine(A) on DNA conductivity was studied by density functional theory combined with non-equilibrium Green’s function. The results show that the formed diaminopurine(D) could pair with thymine(T) through three hydrogen bonds. Owing to the new formed hydrogen bond by amino modification, the binding between the paired bases D and T was tighter than that in AT. Energy gaps and ionization energies of the modified systems were greatly decreased. And the UV absorption spectra are red shifted with more charge-transfer transitions for DT. Properties of the transverse charge transport along hydrogen bonds and the longitudinal charge transport along DNA strand directly demonstrated that replacing A with D could largely increase the conductivity of DNA. More importantly, the mechanism of enhancement effect was indicated. The amino modification adjusted the HOMO(highest occupied molecular orbital) level of DT base pair closer to that of GC compared with AT, thus reducing the energy barrier of hole migration in DNA. This may shed some light on the design of novel DNA-based molecular devices.

Key words: DNA modification, Diaminopurine, Charge transport, Conductivity of DNA, Hole migration

CLC Number: 

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