Physisorption of DNA Nucleobases on h-BN and Graphene: vdW-Corrected DFT Calculations

Abstract

We present a comparative study of DNA nucleobases [guanine (G), adenine (A), thymine (T), and cytosine (C)] adsorbed on hexagonal boron nitride (h-BN) sheet and graphene, using local, semilocal, and van der Waals (vdW) energy-corrected density-functional theory (DFT) calculations. Intriguingly, despite the very different electronic properties of BN sheet and graphene, we find rather similar binding energies for the various nucleobase molecules when adsorbed on the two types of sheets. The calculated binding energies of the four nucleobases using the local, semilocal, and DFT+vdW schemes are in the range of 0.54 ∼ 0.75 eV, 0.06 ∼ 0.15 eV, and 0.93 ∼ 1.18 eV, respectively. In particular, the DFT+vdW scheme predicts not only a binding energy predominantly determined by vdW interactions between the base molecules and their substrates decreasing in the order of G>A>T>C, but also a very weak hybridization between the molecular levels of the nucleobases and the π-states of the BN sheet or graphene. This physisorption of G, A, T, and C on the BN sheet (graphene) induces a small interfacial dipole, giving rise to an energy shift in the work function by 0.11 (0.22), 0.09 (0.15), −0.05 (0.01), and 0.06 (0.13) eV, respectively.

A graphene field-effect transistor as a molecule-specific probe of DNA nucleobases

“…When a molecule is brought into contact with graphene, there are several physical effects that can influence the energy alignment of the molecular and graphene levels at the interface 41 . Previous DFT calculations of DNA nucleobases adsorbed on graphene have predicted that nucleobases interact with graphene only weakly, predominantly by van der Waals interactions 4,13,16 . The frontier molecular orbitals (highest occupied and lowest unoccupied molecular orbitals) lie far from the Fermi level of graphene 13 .…”

“…Previous DFT calculations of DNA nucleobases adsorbed on graphene have predicted that nucleobases interact with graphene only weakly, predominantly by van der Waals interactions 4,13,16 . The frontier molecular orbitals (highest occupied and lowest unoccupied molecular orbitals) lie far from the Fermi level of graphene 13 . As a result there is only a very weak hybridization between the molecular levels of the nucleobases and the low-lying p-states of graphene, leading to a negligible charge transfer between the molecules and graphene 13 .…”

“…Ultimately, these interactions need to induce electronic modifications that are detectable by graphene electrical devices. Although the interaction of DNA nucleobases with graphene have been studied theoretically using molecular dynamics simulation and density functional theory (DFT) methods [12][13][14][15][16] , the experimental evidence of such specific interaction in electrical transport within the graphene has not yet been demonstrated.…”

Graphene nanodevices for DNA sequencing

“…The main contribution is attributed to π-π bonding, which explains why ssDNA binds more strongly to graphene than dsDNA where the bases are hydrogen bonded and stacked within the helical structure [93,94]. The interaction strengths of the different bases with graphene vary as it depends on the polarizability of the DNA bases [93,95]. Both theoretical and experimental studies report that guanine binds most strongly to graphene while A, T and C have lower and similar interaction strengths [93,[96][97][98][99][100].…”

Dispersion corrected DFT approaches for anharmonic vibrational frequency calculations: nucleobases and their dimers

“…[1][2][3][4][5][6][7][8] . A comprehensive analysis of the properties of these systems could be very useful for designing highly biocompatible materials and specific biosensors [9][10][11][12][13][14] .…”