DNA Base Detection Using a Single-Layer MoS₂

Abstract

Nanopore-based DNA sequencing has led to fast and high-resolution recognition and detection of DNA bases. Solid-state and biological nanopores have low signal-to-noise ratio (SNR) (< 10) and are generally too thick (> 5 nm) to be able to read at single-base resolution. A nanopore in graphene, a 2-D material with sub-nanometer thickness, has a SNR of ∼3 under DNA ionic current. In this report, using atomistic and quantum simulations, we find that a single-layer MoS2 is an extraordinary material (with a SNR > 15) for DNA sequencing by two competing technologies (i.e., nanopore and nanochannel). A MoS2 nanopore shows four distinct ionic current signals for single-nucleobase detection with low noise. In addition, a single-layer MoS2 shows a characteristic change/response in the total density of states for each base. The band gap of MoS2 is significantly changed compared to other nanomaterials (e.g., graphene, h-BN, and silicon nanowire) when bases are placed on top of the pristine MoS2 and armchair MoS2 nanoribbon, thus making MoS2 a promising material for base detection via transverse current tunneling measurement. MoS2 nanopore benefits from a craftable pore architecture (combination of Mo and S atoms at the edge) which can be engineered to obtain the optimum sequencing signals.

Single-layer MoS2 nanopores as nanopower generators

“…21). However we also notice that, as with other nanofluidic systems 5,20 , the surface charge density varies from pore to pore, which means that different pores can have disparate values of the equilibrium constant, owing to the various combinations of Mo and S atoms 14 at the edge of the pores (as illuminated by molecular-dynamics simulations 7 ). Next, we introduced a chemical potential gradient by using the KCl concentration gradient system 5 .…”

“…12). We use our MoS 2 nanopore generator to power a MoS 2 transistor, thus demonstrating a self-powered nanosystem.MoS 2 nanopores have already demonstrated better water-transport behaviour than graphene 13,14 owing to the enriched hydrophilic surface sites (provided by the molybdenum) that are produced following either irradiation with transmission electron microscopy (TEM) 15 or electrochemical oxidation 16 . The osmotic power is generated by separating two reservoirs containing potassium chloride (KCl) solutions of different concentrations with a freestanding MoS 2 membrane, into which a single nanopore has been introduced 13 .…”

Identification of single nucleotides in MoS2 nanopores

“…Single-layer MoS 2 also has a direct bandgap of at least 1.8 eV (refs 4, 22), a feature that is essential for electronic base detection with field-effect transistors (FETs) 4,23 . Therefore, MoS 2 is a promising material for single-nucleotide detection, as was recently computationally demonstrated by Farimani and co-authors 24 .…”

Comparison of MoS2, WS2, and Graphene Oxide for DNA Adsorption and Sensing

“…[16][17][18][19] Using these two materials for DNA-based sensing was reported with simple DNA oligonucleotides, [20][21][22][23][24][25][26][27] as well as aptamers, 28,29 and DNAzymes. 30 Thiolated DNA was also attached to AuNPs to improve sensing based the intrinsic photoluminescence property of MoS2.…”