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 (θ) 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.
