Design of Biosensors Based Transition-Metal Dichalcogenide for DNA-base Detection: A First-Principles Density Functional Theory Study

A biosensor can be defined as a device that sense a biologically specific material and response. The main function of sensing platform, as a one of the hottest topic attracting scientific minds, playing an important role in biosensors. In this paper, we theoretically reveal the electronic structures of mMoS2 doped by 3d transition metals. Furthermore, adsorption of nucleic acids (Adenine (A), Cytosine (C), Guanine (G), Thymine (T) and Uracil (U)) on monolayers of modified transition-metal dichalcogenides (mTMDs) such as molybdenum disulfide (MoS2) and tungsten disulfide (WS2) as a sensing platform is compared using first-principles density functional theory (DFT). We found that all nucleobases are physisorbed on TMDs due to van der Waals (vdW) interactions demonstrating that MoS2 is better than other TMDs and may also be used to detect nucleic acid sequence for medical science. Interestingly, the adsorption energies, band structures, electronic properties and magnetic behavior of the transition metal (TM) atom adsorbed mMoS2 have been systematically investigated. The theoretical results show that structures of mMoS2 efficiently modified by absorbing different TM atoms which related to their number of d electrons. The order of binding energies of the nucleobases adsorbed on MoS2 and WS2 is G A T C U using DFT-D3 method.