Electronic Signature of DNA Nucleotides via Transverse Transport

Abstract

We report theoretical studies of charge transport in single-stranded DNA in the direction perpendicular to the backbone axis. We find that, if the electrodes which sandwich the DNA have the appropriate spatial width, each nucleotide carries a unique signature due to the different electronic and chemical structure of the four bases. This signature is independent of the nearest-neighbor nucleotides. Furthermore, except for the nucleotides with Guanine and Cytosine bases, we find that the difference in conductance of the nucleotides is large for most orientations of the bases with respect to the electrodes. By exploiting these differences it may be possible to sequence single-stranded DNA by scanning its length with conducting probes.

Electrical Conductance in Biological Molecules

“…The physical-chemical modalities of the above-mentioned sensors are hot topic for the present, they are systematically studied by several groups using theoretical approaches and cause vivid debates in the literature (see, for example, works [124][125][126][127][128][129][130][131] and the references therein).…”

Single-Molecule Analysis Methods Using Nanogap Electrodes and Their Application to DNA Sequencing Technologies

“…As a result, we predicted that single-base molecules between nanoelectrodes will have conformations that are energetically stable, and as a result, the single-molecule conductance measurements will obtain only single peaks for them. 31,32,102,103 The conductance histograms of all of the base molecules tested by us were found to have large dispersions. The tunneling current flowing through a molecule strongly depends on the distance between the molecule and the electrodes and the conformation of the molecule.…”

“…Theoretical calculations support this prediction. 31,32,102,103 However, because the degrees of freedom of base molecules in DNA are limited by chemical bonds, the variance of the histograms of base molecules in DNA is actually smaller than the variance for individual base molecules. 37 As is shown in Figure 21, there is an order in the various values of the peak conductance of each conductance histogram.…”

DNA-based thermoelectric devices: A theoretical prospective

“…8 Since both the location and the magnitude of these peaks sensitively depend on the energetics of the considered trimer, one may think of introducing a thermoelectric signature for different codons of biological interest, 7 in close analogy with the transversal electronic signature recently proposed for single-stranded DNA chains. 9,10 In this work, we will analyze the thermoelectric response of more realistic double-stranded DNA ͑dsDNA͒ chains, hence extending our previous results in order to perform a theoretical prospective on the potential of synthetic DNA chains as thermoelectric materials. Duplex DNA molecules can be classified into biological ͑i.e., samples extracted from living organisms͒ and artificially engineered molecules ͓e.g., poly͑dG͒-poly͑dC͒ or poly͑dA͒-poly͑dT͒ chains͔.…”