First principal Study of Adenine, Cytosine, Guanine and Thymine of Nucleobase DNA on Graphene Layer

Abstract

First principal study of tuning transport properties of nucleobase DNA molecules, such as adenine (A), cytosine (C), guanine (G), and thymine (T) adsorbed onto Graphene quantum dots layer was studied. All calculations were performed by using an ab initio method and non-equilibrium Green’s function. The transport properties, such as density of state (DOS), transmission co-efficient (TE), energy level, and current voltage characteristics are investigated. The adsorption energy of cytosine on GQDs was -0.039 which is greater than thymine, adenine and guanine and their energy was -0.0684, -0.1034, -0.5873 eV respectively (C > T > A > G). Results show that DNA binding in a single layer of graphene quantum dots significantly affects conductance capacity.  It has been demonstrated that the thymine molecule interacts strongly with the graphene quantum dots layer in terms of all transport properties. Therefore, larger current is available in the graphene quantum dots layer with adsorbed thymine molecule. It is clear that adsorbed guanine molecule onto GQDs layer show greater resonant peaks in between 25 and 30eV in DOS, whereas adsorbed adenine, cytosine and thymine molecule onto GQDs layer show nearly equal smaller peaks in between 20 and 25eV respectively (G > A C  T). The adsorbed Guanine molecule onto GQDs layer offers more energy levels and improved conductivity since it has more resonance peaks and a smaller gap between them. It was indicated by theoretical studies that we can use these Graphene quantum dots-based DNA molecules as cell imaging and as swapping components in upcoming applications. One of the most revolutionary technologies of this decade may be quick, inexpensive, and accurate DNA sequencing, which may open the door to personalized treatment.