Phosphorene and Silicene Nanodevices for DNA Sequencing: Ab Initio Studies

Graphene’s success for nanopore DNA sequencing has shown that it is possible to explore other potential single- 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 studied the interaction of DNA bases with finite-size nanomaterials from phosphorene and silicene. We observe that binding energies of DNA bases using nanopores and nanoribbon from phosphorene are smaller compared to graphene and silicene devices. This shows that minimal sticking of DNA bases to phosphorene’s surface is expected for phosphorene devices. Furthermore, both nanopore and nanoribbon devices from phosphorene show a characteristic change in the density of states for each base. The band gap of phosphorene is significantly changed compared to other nanomaterials (e.g., MoS₂, graphene, silicene, and h-BN) due to physisorption of bases on nanoribbon surface. Our findings show that phosphorene performs better than silicene and graphene, hence a promising material for DNA base detection using advanced detection principles such as transverse tunneling current measurement.