Adsorption of cytosine on Si and Ge doped graphene: A DFT study

Abstract

This study describes how the cytosine adsorption on Si and Ge-doped Graphene uses density functional theory (DFT) calculations. The adsorption energies of cytosine on Si and Ge-doped Graphene are computed. The method used a hybrid B3LYP approach with 6-31G (d,p) and LANL2DZ basis sets to determine the Highest Occupied Molecular Orbital -Lowest Unoccupied Molecular Orbital HOMO and LUMO states and descriptors; and charge distribution potential. According to charge distributions, both Ge-doped and Si-doped graphene structures are sensitive to the cytosine base. The DNA base cytosine plays a crucial role as an adsorbent. When cytosine was adsorbed on Ge- and Si-doped graphene structures, the Highest Occupied Molecular Orbital -Lowest Unoccupied Molecular Orbital (HOMO-LUMO) gap decreased. This finding implies that the electrical conductivity of both systems has increased. The result shows that the Ge- and Si-doped graphene structures might be introduced as strong adsorbents for biosensor applications in various fields.