APS March Meeting 2024
Monday–Friday, March 4–8, 2024;
Minneapolis & Virtual
Session OD01: V: On-Demand Presentations - Available throughout March Meeting
6:00 AM,
Sunday, March 3, 2024
Abstract: OD01.00024 : Electronic Interactions of DNA nucleobases with Single-Layer Ti3C2 MXene and Graphene: DFT and NEGF Studies*
Abstract
Presenter:
Benjamin O Tayo
(University of Central Oklahoma)
Authors:
Benjamin O Tayo
(University of Central Oklahoma)
Michael Walkup
(University of Central Oklahoma)
Serkan Caliskan
(University of Houston-Clear Lake)
Recently, 2D MXenes have emerged as promising alternative materials for DNA nucleobase detection. A recent molecular dynamics simulation study using Ti3C2 MXene nanopores showed its potential for detecting nucleobases based on physical features such as ionic current and dwell time. However, molecular dynamics simulation can’t capture the electronic interactions between nucleobases and Ti3C2 which are very crucial for nucleobase detection. We investigated the electronic interaction of DNA nucleobases [adenine (A), guanine (G), thymine (T), and cytosine (C)] with single-layer Ti3C2 MXene using vdW-corrected DFT and NEGF methods. All calculations were benchmarked against graphene. We showed that depending on the initial vertical height of a nucleobase above the Ti3C2 surface, two interaction mechanisms are possible, namely: physisorption and chemisorption. For graphene, DNA nucleobases always physisorped onto the graphene surface irrespective of the initial vertical height of nucleobase above graphene sheet. The PBE+vdW binding energies for graphene are high (0.55 – 0.74 eV) and follow the order G > A > T > C, with adsorption heights in the range 3.16 – 3.22 Å, indicating strong physisorption. For Ti3C2, the PBE+vdW binding energies are relatively weaker (0.16 – 0.20 eV) and follow the order A > G = T > C, with adsorption heights in the range 5.51 – 5.60 Å indicating weak physisorption. The binding energies for chemisorption follow the order G > A >T > C, which is the same order for physisorption. The binding energy values (5.3 – 7.5 eV) indicate very strong chemisorption (~40 times larger than the physisorption binding energies). Furthermore, our band structure and electronic transport analysis showed that for physisorption, there are neither significant variation in band structure nor modulations in the transmission function and device density of states (DDOS). The relatively weak physisorption and strong chemisorption shows that Ti3C2 might not be capable of identifying DNA nucleobases using the physisorption method.
*This research was supported by National Institutes of General Medical Sciences (NIGMS) of the National Institutes of Health under award number 1R15GM140445-01A1.