Physisorption behaviors of deoxyribonucleic acid nucleobases and base pairs on bismuthene from theoretical insights

Abstract

In this article, we conduct a density functional theory (DFT) investigation to reveal the adsorption characteristics of single deoxyribonucleic acid (DNA) nucleobases and hydrogen-bonded base pairs on monolayer bismuthene. The calculation results show that adenine (A), cytosine (C), guanine (G), thymine (T) interact with bismuthene in the following strength order: G > C > A > T. The magnitude of the adsorption energy is found to be 0.83 eV, 0.69 eV, 0.65 eV, 0.59 eV, respectively. These distinguishable energy levels make bismuthene a potential surface for selective detection of the four bases. During the adsorption processes, A, G, and T take charge from the adsorbent, whereas C provides charge to the adsorbent. Through electronic properties analyses, we demonstrate their physisorption essence. The key role of single oxygen atom in stronger interactions between bismuthene and C/G is also concluded. The theoretical desorption time of adsorbed G and T at 398 K are 3.21 × 10−2 s and 2.94 × 10−5 s. In addition, A-T and C-G pairs can be adsorbed on bismuthene with an adsorption energy of − 1.20 eV and − 1.26 eV. According to the detailed parameters of the pairs before and after adsorption, the hydrogen bonds between complementary bases can remain stable under the effect of bismuthene.