Robust signatures in the current–voltage characteristics of DNA molecules oriented between two graphene nanoribbon electrodes

Abstract

In this work, we numerically calculate the electric current through three kinds of DNA sequences (telomeric, λ-DNA and p53-DNA) described by different heuristic models. A bias voltage is applied between two zigzag edged graphene contacts attached to the DNA segments, while a gate terminal modulates the conductance of the molecule. Calculation of the current is performed by integrating the transmission function (calculated using the lattice Green's function) over the range of energies allowed by the chemical potentials. We show that a telomeric DNA sequence, when treated as a quantum wire in the fully coherent low-temperature regime, works as an excellent semiconductor. Clear steps are apparent in the current-voltage curves of telomeric sequences and are present independent of length and sequence initialization at the contacts. We also find that the molecule-electrode coupling can drastically influence the 5

Conformation dependent electronic transport in a DNA double-helix

“…We take interstrand hopping parameter to be v = 0.3eV . We emphasize that in case of the extended ladder model [42,43], diagonal hopping between different nucleotides are also taken into account. But as in our case no diagonal hopping being considered, we compensate this by taking a quite larger value of interstrand hopping parameter v. Now as all the nucleotides are connected with sugar-phosphate backbones by identical C-N bonds, we take the hopping parameter between a base and corresponding backbone site same for all t b = 0.7eV [32].…”

Sequence dependency of the thermodynamic properties of long DNA double-strands

“…In general, the theoretical studies on DNA can be classied into two main groups of ab initio calculations [31][32][33][34][35][36][37] and the model-based Hamiltonian approach. [38][39][40][41][42][43][44][45][46][47][48][49] Although the former method operates in a more fundamental way and provides more detail, it is very time-consuming for systems that are not small. The latter technique is generally favored when dealing with large systems wherein optimizing a few parameters can reproduce experimental results and reliable data.…”

Periodic, quasiperiodic, fractal, Kolakoski, and random binary polymers: Energy structure and carrier transport

“…Several works have been devoted to the study of transfer and transport in specific DNA structures (periodic [5][6][7]28,29 , quasiperiodic [30][31][32] , random and natural 19,20,[33][34][35] ) using variants of the Tight-Binding (TB) method. Here, we employ the TB wire model, with the sites of the chain being the base pairs, to study the spectral, localization and charge transport properties of periodic, deterministic aperiodic [Thue-Morse (TM), Fibonacci (F), Period Doubling (PD), Rudin-Shapiro (RS), Cantor set (CS), generalized Cantor set (GCS), Kolakoski (KOL)] and random DNA binary segments.…”