<i>Ab initio</i> calculations of DNA/RNA nucleobases with blue/black phosphorene for electronic sensing applications

Nucleobases (NBs), essential biomolecules underpinning numerous biological processes, were investigated for their adsorption mechanisms on black phosphorene (BlackP) and blue phosphorene (BlueP) monolayers using first-principles van der Waals (vdW) calculations. The study examined guanine (G), cytosine (C), adenine (A), thymine (T), and uracil (U) as adsorbates. The adsorption strength between DNA/RNA nucleobases and BlackP followed the trend G > A > C > T > U. At the same time, BlueP exhibited G > C > A > T > U. It aligns with theoretical studies in the literature on the interaction between BlueP/BlackP and NBs. Furthermore, the influence of these interactions on the electronic properties was uniquely investigated in detail. The most notable result obtained is the significant change in the band structures of BlueP upon interaction with G and A. Furthermore, this study uniquely investigates the adsorption mechanisms of NBs on BlackP and BlueP under the effect of charging by focussing on the impact on electronic properties for the first time. The results suggest a potential semiconductor-metal-semiconductor (SMS) transition for NBs on BlueP under charging. Compared to other NBs, A has a distinct influence on BlueP at the state of Sigma Q = + 2 e/cell. Also, the effects of NBs on the transport properties of BlackP/BlueP monolayers have been investigated in detail for the first time. At a gate voltage (Vg) of 0.30 V, the BlackP sensor demonstrates improved sensitivity towards C, G, and U. Therefore, this study provides insights for developing the devices detecting the NBs.