Concepts on charge transfer through naturally vibrating DNA molecule

Delocalization of charges thorough DNA occurs due to the natural and continuous movements of molecule which stimulates the charge transfer through the molecule. A model is presented showing that the mechanism of electrical conduction occurs mainly by thermally-activated drift motion of holes under control of the localized carriers; where electrons are localized in the conduction band. These localized (stationary-trapped) electrons control the movements of the positive charges and do not play an effective role in the electrical conduction itself. It is found that the localized charge-carriers in the bands have characteristic relaxation times at 5 × 10^− 2 s, 1.94 × 10^− 4 s, 5 × 10^− 7 s, and 2 × 10^− 11 s respectively which are corresponding to four intrinsic thermal activation energies 0.56 eV, 0.33 eV, 0.24 eV, and 0.05 eV respectively. The ac-conductivity of some published data are well fitted with the presented model and the total charge density in DNA molecule is calculated to be n = 1.88 × 10^19 cm^− 3 at 300 K which is corresponding to a linear electron density n = 8.66 × 10^3 cm^− 1 at 300 K. The model shed light on the role of transfer and/or localization of charges through DNA which has multiple applications in medical, nano-technical, bio-sensing and different domains. So, repair DNA by adjusting the charge transport through the molecule is future challenges to new medical applications.

Figure optionsDownload high-quality image (164 K)Download as PowerPoint slideHighlights
► A model is presented to explain the role of localized electrons in the bands.
► Delocalization of charges thorough DNA occurs due to its natural movements.
► The localized electrons control the transfer of the positive charges.
► Localized charge-carriers have characteristic relaxation times and charge density.
► Each DNA molecule has four intrinsic thermal activation energies.