scholarly journals DNA Translocation Through Vertically Stacked 2D Layers of Graphene & Hexagonal Boron Nitride Heterostructure Nanopore

2020 ◽  
Author(s):  
Ramkumar Balasubramanian ◽  
Sohini Pal ◽  
Anjana Rao ◽  
Akshay Naik ◽  
Banani Chakraborty ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Single Molecule ◽  
Hexagonal Boron Nitride ◽  
Membrane Surface ◽  
Cost Effective ◽  
Dna Bases ◽  
Dna Translocation ◽  
Sensing Applications ◽  
Dna Strands ◽  
Signal Variability

Cost effective, fast and reliable DNA sequencing can be enabled by advances in nanopore based methods, such as the use of atomically thin graphene membranes. However, strong interaction of DNA bases with graphene leads to undesirable effects such as sticking of DNA strands to the membrane surface. While surface functionalization is one way to counter this problem, here we present another solution based on a heterostructure nanopore system, consisting of a monolayer of graphene and hexagonal Boron Nitride (hBN) each. Molecular dynamics studies of DNA translocation through this heterostructure nanopore revealed a surprising and crucial influence of heterostructure layer order in controlling the base specific signal variability. Specifically, the heterostructure with graphene on top of hBN had nearly 3-10x lower signal variability than the one with hBN on top of graphene. Simulations point to the role of differential underside sticking of DNA bases as a possible reason for the observed influence of layer order. Our studies can guide the development of experimental systems to study and exploit DNA translocation through two-dimensional heterostructure nanopores for single molecule sequencing and sensing applications.

scholarly journals DNA Translocation Through Vertically Stacked 2D Layers of Graphene & Hexagonal Boron Nitride Heterostructure Nanopore

2020 ◽  
Author(s):  
Ramkumar Balasubramanian ◽  
Sohini Pal ◽  
Anjana Rao ◽  
Akshay Naik ◽  
Banani Chakraborty ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Single Molecule ◽  
Hexagonal Boron Nitride ◽  
Membrane Surface ◽  
Cost Effective ◽  
Dna Bases ◽  
Dna Translocation ◽  
Sensing Applications ◽  
Dna Strands ◽  
Signal Variability

Cost effective, fast and reliable DNA sequencing can be enabled by advances in nanopore based methods, such as the use of atomically thin graphene membranes. However, strong interaction of DNA bases with graphene leads to undesirable effects such as sticking of DNA strands to the membrane surface. While surface functionalization is one way to counter this problem, here we present another solution based on a heterostructure nanopore system, consisting of a monolayer of graphene and hexagonal Boron Nitride (hBN) each. Molecular dynamics studies of DNA translocation through this heterostructure nanopore revealed a surprising and crucial influence of heterostructure layer order in controlling the base specific signal variability. Specifically, the heterostructure with graphene on top of hBN had nearly 3-10x lower signal variability than the one with hBN on top of graphene. Simulations point to the role of differential underside sticking of DNA bases as a possible reason for the observed influence of layer order. Our studies can guide the development of experimental systems to study and exploit DNA translocation through two-dimensional heterostructure nanopores for single molecule sequencing and sensing applications.

scholarly journals 2D-3D integration of hexagonal boron nitride and a high-κ dielectric for ultrafast graphene-based electro-absorption modulators

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hitesh Agarwal ◽  
Bernat Terrés ◽  
Lorenzo Orsini ◽  
Alberto Montanaro ◽  
Vito Sorianello ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Hafnium Oxide ◽  
High Speed ◽  
Hexagonal Boron Nitride ◽  
Temperature Stability ◽  
Cost Effective ◽  
Fold Increase ◽  
Building Blocks ◽  
High Quality ◽  
New Device

AbstractElectro-absorption (EA) waveguide-coupled modulators are essential building blocks for on-chip optical communications. Compared to state-of-the-art silicon (Si) devices, graphene-based EA modulators promise smaller footprints, larger temperature stability, cost-effective integration and high speeds. However, combining high speed and large modulation efficiencies in a single graphene-based device has remained elusive so far. In this work, we overcome this fundamental trade-off by demonstrating the 2D-3D dielectric integration in a high-quality encapsulated graphene device. We integrated hafnium oxide (HfO2) and two-dimensional hexagonal boron nitride (hBN) within the insulating section of a double-layer (DL) graphene EA modulator. This combination of materials allows for a high-quality modulator device with high performances: a ~39 GHz bandwidth (BW) with a three-fold increase in modulation efficiency compared to previously reported high-speed modulators. This 2D-3D dielectric integration paves the way to a plethora of electronic and opto-electronic devices with enhanced performance and stability, while expanding the freedom for new device designs.

scholarly journals Noble metal supported hexagonal boron nitride for the oxygen reduction reaction: a DFT study

2019 ◽  
Vol 1 (1) ◽  
pp. 132-139 ◽  
Author(s):  
Seoin Back ◽  
Samira Siahrostami
Keyword(s):  
Boron Nitride ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Density Functional ◽  
Hexagonal Boron Nitride ◽  
Density Functional Theory Calculations ◽  
Cost Effective ◽  
Reduction Reaction ◽  
Functional Theory ◽  
The Stability

Discovering active, stable and cost-effective catalysts for the oxygen reduction reaction (ORR) is of utmost interest for commercialization of fuel cells. Herein, we use density functional theory calculations to systematically study metal supported hexagonal boron nitride as ORR catalysts. Our results indicate that this strategy is a promising to increase the stability against CO poisoning as well as to activate inert h-BN toward the ORR.

scholarly journals Translocation of flexible and tensioned ssDNA through in silico designed hydrophobic nanopores with two constrictions

2020 ◽  
Author(s):  
Punam Rattu ◽  
Taylor Haynes ◽  
E. Jayne Wallace ◽  
Syma Khalid
Keyword(s):  
Dna Bases ◽  
Dna Conformation ◽  
Window Of Opportunity ◽  
Pore Width ◽  
Dna Translocation ◽  
Aromatic Residues ◽  
Dna Strands ◽  
Dna Backbone ◽  
The Impact ◽  
Constriction Region

ABSTRACTProtein-inspired nanopores with hydrophobic constriction regions have previously been shown to offer some promise for DNA sequencing. Here we explore a series of pores with two hydrophobic constrictions. The impact of nanopore radius, the nature of residues that define the constriction region and the flexibility of the ssDNA is explored. Our results show that aromatic residues slow down DNA translocation, and in the case of short DNA strands, they cause deviations from a linear DNA conformation. When DNA is under tension, translocation is once again slower when aromatic residues are present in the constriction. However, the lack of flexibility in the DNA backbone provides a narrower window of opportunity for the DNA bases to be retained inside the pore via interaction with the aromatic residues, compared to more flexible strands. Consequently, there is more variability in translocation rates for strands under tension. DNA entry into the pores is correlated to pore width, but no such correlation between width and translocation rate is observed.

scholarly journals DNA Translocation through Hydrophilic Nanopore in Hexagonal Boron Nitride

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Zhi Zhou ◽  
Ying Hu ◽  
Hao Wang ◽  
Zhi Xu ◽  
Wenlong Wang ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Dna Translocation

scholarly journals FRET-Based Aptasensor for the Selective and Sensitive Detection of Lysozyme

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 914 ◽  
Author(s):  
Kumar Sapkota ◽  
Soma Dhakal
Keyword(s):  
Single Molecule ◽  
Immune Modulation ◽  
Dynamic Range ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Cost Effective ◽  
Protein Biomarkers ◽  
Dna Strands ◽  
Lysozyme Concentration ◽  
Aptamer Sensor

Lysozyme is a conserved antimicrobial enzyme and has been cited for its role in immune modulation. Increase in lysozyme concentration in body fluids is also regarded as an early warning of some diseases such as Alzheimer’s, sarcoidosis, Crohn’s disease, and breast cancer. Therefore, a method for a sensitive and selective detection of lysozyme can benefit many different areas of research. In this regard, several aptamers that are specific to lysozyme have been developed, but there is still a lack of a detection method that is sensitive, specific, and quantitative. In this work, we demonstrated a single-molecule fluorescence resonance energy transfer (smFRET)-based detection of lysozyme using an aptamer sensor (also called aptasensor) in which the binding of lysozyme triggers its conformational switch from a low-FRET to high-FRET state. Using this strategy, we demonstrated that the aptasensor is sensitive down to 2.3 picomoles (30 nM) of lysozyme with a dynamic range extending to ~2 µM and has little to no interference from similar biomolecules. The smFRET approach used here requires a dramatically small amount of aptasensor (~3000-fold less as compared to typical bulk fluorescence methods), and it is cost effective compared to enzymatic and antibody-based approaches. Additionally, the aptasensor can be readily regenerated in situ via a process called toehold mediated strand displacement (TMSD). The FRET-based aptasensing of lysozyme that we developed here could be implemented to detect other protein biomarkers by incorporating protein-specific aptamers without the need for changing fluorophore-labeled DNA strands.

scholarly journals High-Resolution Optical Imaging and Sensing Using Quantum Emitters in Hexagonal Boron-Nitride

2021 ◽  
Vol 9 ◽  
Author(s):  
Carlo Bradac
Keyword(s):  
High Resolution ◽  
Boron Nitride ◽  
Optical Imaging ◽  
Hexagonal Boron Nitride ◽  
Imaging Techniques ◽  
Super Resolution ◽  
Sensing Applications ◽  
Resolution Imaging ◽  
Super Resolution Microscopy ◽  
Quantum Emitters

Super-resolution microscopy has allowed optical imaging to reach resolutions well beyond the limit imposed by the diffraction of light. The advancement of super-resolution techniques is often an application-driven endeavor. However, progress in material science plays a central role too, as it allows for the synthesis and engineering of nanomaterials with the unique chemical and physical properties required to realize super-resolution imaging strategies. This aspect is the focus of this review. We show that quantum emitters in two-dimensional hexagonal boron nitride are proving to be excellent candidate systems for the realization of advanced high-resolution imaging techniques, and spin-based quantum sensing applications.

DNA Translocation through Vertically Stacked 2D Layers of Graphene and Hexagonal Boron Nitride Heterostructure Nanopore

2020 ◽  
Author(s):  
Ramkumar Balasubramanian ◽  
Sohini Pal ◽  
Anjana Rao ◽  
Akshay Naik ◽  
Banani Chakraborty ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Dna Translocation

Marcus-Hush Theory Revealed by Electron Tunneling Through Hexagonal Boron Nitride

2019 ◽  
Author(s):  
Matěj Velický ◽  
Sheng Hu ◽  
Colin R. Woods ◽  
Peter S. Toth ◽  
Viktor Zólyomi ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Boron Nitride ◽  
Electron Tunneling ◽  
Hexagonal Boron Nitride ◽  
Large Body ◽  
Liquid Solution ◽  
Limiting Current ◽  
Electron Transfer Rate Constant ◽  
Electrochemical Parameters ◽  
Voltammetric Measurements

Marcus-Hush theory of electron transfer is one of the pillars of modern electrochemistry with a large body of supporting experimental evidence presented to date. However, some predictions, such as the electrochemical behavior at microdisk electrodes, remain unverified. Herein, we present a study of electron tunneling across a hexagonal boron nitride barrier between a graphite electrode and redox levels in a liquid solution. This was achieved by the fabrication of microdisk electrodes with a typical diameter of 5 µm. Analysis of voltammetric measurements, using two common redox mediators, yielded several electrochemical parameters, including the electron transfer rate constant, limiting current, and transfer coefficient. They show a significant departure from the Butler-Volmer behavior in a clear manifestation of the Marcus-Hush theory of electron transfer. In addition, our system provides a novel experimental platform, which could be applied to address a number of scientific problems such as identification of reaction mechanisms, surface modification, or long-range electron transfer.

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