Session: 03-13-01: Conference-Wide Symposium on Biomedical Manufacturing & Materials

Paper Number: 116801

116801 - Molybdenum Disulfide Solid-State Nanopores for Single-Molecule Biosensing 

Solid-state nanopores (SSN) are sensors for detecting analytes with single molecule resolution with advantages such as high-throughput and label-free detection. While biological nanopores have shown great promise as a tool for fast and low-cost DNA/RNA sequencing, SSNs suffer from the disadvantage of relatively low spatial resolution for discerning base pairs of a DNA molecule. Silicon nitride is the ubiquitous membrane material for SSNs and even the thinnest silicon nitride membranes are still a few nm thick, thus, unable to achieve single base resolution. In recent years, 2D materials such as graphene, hexagonal boron nitride (hBN) and molybdenum disulfide (MoS₂) have gained traction as a suitable membrane material for SSNs, especially for DNA sequencing applications. 2D materials can range from a single layer to a few atomic layers of thickness. The main advantage of 2D materials over silicon nitride as membranes for SSNs is their ability to achieve high spatial resolution. They are also characterized by superior mechanical strength and favorable optical and electronic properties compared to silicon nitride. Among the 2D materials, MoS₂ has emerged as a promising option with several advantages over graphene and hBN. MoS₂ belongs to the transition metal dichalcogenides (TMDCs). The Mo and S atoms of MoS₂ are covalently bonded with weak van der Waals forces in a hexagonal arrangement, with the positively charged Mo atoms sandwiched between the negatively charged surface S atoms forming a three-layered, 2D, semiconducting material. MoS₂ is characterized by the presence of a direct bandgap, which is one of the disadvantages of graphene. Other advantages of MoS₂ over graphene are lower hydrophobicity and relatively high bending rigidity. Here, we review the application and potential of MoS₂ as SSN membrane material for DNA and protein sensing. In this review, we discuss the mechanical properties of MoS₂ membranes, fabrication methods of MoS₂ layers, and the process of MoS₂ transfer on silicon substrates. Exfoliation and chemical vapor deposition (CVD) methods are used to produce thin layers of MoS₂.The most common method of fabricating nanopores on MoS₂ membranes is using a focused electron beam of a transmission electron microscope (TEM) while electrochemical reaction (ECR)-based pore formation method has also been successfully employed. We have also critically reviewed various theoretical and experimental studies that have reported using MoS₂ nanopores for single molecule studies. While the overall number of MoS₂ nanopore devices reported is low, the results obtained promise greater application of such devices for single molecule sensing.

 

Presenting Author: Jugal Saharia The University of Texas Permian Basin

Presenting Author Biography: I am a Visiting Assistant Professor in the Department of Mechanical Engineering at The University of Texas Permian Basin. My specialization is Thermal-Fluids Science. My research focus is solid-state nanopores for single-molecule studies.

Authors:

Jugal Saharia The University of Texas Permian Basin
y.m. Nuwan d.y. Bandara The Australian National University
Lokesh Saharan The University of Texas Permian Basin