Identification of DNA bases using nanopores created in finite-size nanoribbons from graphene, phosphorene, and silicene

Abstract

Graphene’s success for nanopore deoxyribonucleic acid (DNA) sequencing has shown that it is possible to explore other potential single-atom and few-atom thick layers of elemental 2D materials beyond graphene (e.g., phosphorene and silicene) and also that these materials can exhibit fascinating and technologically useful properties for DNA base detection that are superior to those of graphene. Using density functional theory (DFT), we study the interaction of DNA bases with nanopores created in finite-size nanoribbons from graphene, phosphorene, and silicene. Due to the small size of DNA bases, the bases interact with only a small section of the nanoribbon; hence, using a finite-size model is appropriate for capturing the interaction of bases and 2D membrane materials. Furthermore, by using a finite-size model, our system is approximated as a molecular system, which does not require a periodic DFT calculation. We observe that binding energies of DNA bases using nanopores from phosphorene and silicene are similar and generally smaller compared to those from graphene. This shows that minimal sticking of DNA bases to the pore is expected for phosphorene and silicene devices. Furthermore, nanopores from phosphorene and silicene show a characteristic change in the density of states for each base. The bandgaps of phosphorene and silicene are significantly altered due to interaction with DNA bases compared to those of graphene. Our findings show that phosphorene and silicene are promising alternatives to graphene for DNA base detection using advanced detection principles such as transverse tunneling current measurement.