Adsorption Behavior of Nucleobases on Doped MoS2 Monolayer: A DFT Study

摘要

Nucleobases detection is important in DNA sequencing, disease testing linked to genes, and disease treatment. In this work, the interactions of nonmetallic element (Si, P, Cl, Se) doped MoS2 monolayer and nucleobases (A, C, G, T, U) have been studied by first-principles based on density functional theory. Their optimal configurations, the corresponding adsorption energies, charge transfer, and electrical properties are calculated. The adsorption strength and charge transfers after doping Si and P are all larger than that of the pristine MoS2. And they are better at distinguishing nucleobases due to the large standard deviations (theta) of five adsorption energies from same substrate. For the Si-MoS2 monolayer, the nucleobases are perpendicular to its surface, with large charge transfer (0.25e to 0.36e) and adsorption energy (-3.16 to -2.43 eV). And the molecules have significant effects on the electrical properties of Si-MoS2, including band dispersion curve and band gap, due to orbital hybridization between the substrate and the molecules. These results show there's chemical adsorption between them, which suggest that Si-MoS2 monolayer can be used as a potential probe platform to detect biomolecule. While physical adsorption occurs between P-MoS2 and nucleobases with moderate adsorption energy (-1.17 to -0.71 eV) and change transfer (0.13 to 0.34e). After absorbing single nucleobase molecule, the conductivity of P-MoS2 changes, which suggest its distinguishability and sensitivity to these molecules. And the predicted recovery times of A, C, G, T and U are 300 ms, 9 s, 49 s, 5 ms, and 0.09 ms at 400 K, respectively, which indicate that P-MoS2 monolayer has a potential application prospect in DNA/RNA sequencing.