Electrical Conduction in Native Deoxyribonucleic Acid: Hole Hopping Transfer Mechanism?

Measurements of the quasistatic and frequency dependent electric conductivity below 1 MHz were carried out on wet-spun, macroscopically oriented, calf thymus DNA bulk samples, thus effectively extending previous radio frequency data down to quasistatic time scales. The frequency dependence of the electrical conductivity in the frequency range of approximately ${10}^{-3}–{10}^{15}\mathrm{H}\mathrm{z}$ agrees well with predictions of the hopping hole mechanism. Temperature dependence of the quasistatic electrical conductivity can be rather well described by the activated Arrhenius law with the activation energy of $\approx 0.9\mathrm{e}\mathrm{V}$; however, based on the quality of the fits, the hopping ansatz cannot be ruled out.