| 1. |
- Gowtham, S., et al.
(författare)
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First-principles study of physisorption of nucleic acid bases on small-diameter carbon nanotubes
- 2008
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 19:12, s. 125701-
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Tidskriftsartikel (refereegranskat)abstract
- We report the results of our first-principles study based on density functional theory on the interaction of the nucleic acid base molecules adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U), with a single-walled carbon nanotube (CNT). Specifically, the focus is on the physisorption of base molecules on the outer wall of a (5, 0) metallic CNT possessing one of the smallest diameters possible. Compared to the case for CNTs with large diameters, the physisorption energy is found to be reduced in the high-curvature case. The base molecules exhibit significantly different interaction strengths and the calculated binding energies follow the hierarchy G>A>T>C>U, which appears to be independent of the tube curvature. The stabilizing factor in the interaction between the base molecule and CNT is dominated by the molecular polarizability that allows a weakly attractive dispersion force to be induced between them. The present study provides an improved understanding of the role of the base sequence in deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) in their interactions with carbon nanotubes of varying diameters.
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| 2. |
- Amorim, Rodrigo G., et al.
(författare)
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Silicene as a new potential DNA sequencing device
- 2015
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 26:15
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Tidskriftsartikel (refereegranskat)abstract
- Silicene, a hexagonal buckled 2D allotrope of silicon, shows potential as a platform for numerous new applications, and may allow for easier integration with existing silicon-based microelectronics than graphene. Here, we show that silicene could function as an electrical DNA sequencing device. We investigated the stability of this novel nano-bio system, its electronic properties and the pronounced effects on the transverse electronic transport, i.e., changes in the transmission and the conductance caused by adsorption of each nucleobase, explored by us through the non-equilibrium Green's function method. Intriguingly, despite the relatively weak interaction between nucleobases and silicene, significant changes in the transmittance at zero bias are predicted by us, in particular for the two nucleobases cytosine and guanine. Our findings suggest that silicene could be utilized as an integrated-circuit biosensor as part of a lab-on-a-chip device for DNA sequencing.
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| 3. |
- de Souza, Fabio A. L., et al.
(författare)
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Nano-structured interface of graphene and h-BN for sensing applications
- 2016
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 27:36
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Tidskriftsartikel (refereegranskat)abstract
- The atomically-precise controlled synthesis of graphene stripes embedded in hexagonal boron nitride opens up new possibilities for the construction of nanodevices with applications in sensing. Here, we explore properties related to the electronic structure and quantum transport of a graphene nanoroad embedded in hexagonal boron nitride, using a combination of density functional theory and the non-equilibrium Green's functions method to calculate the electric conductance. We find that the graphene nanoribbon signature is preserved in the transmission spectra and that the local current is mainly confined to the graphene domain. When a properly sized nanopore is created in the graphene part of the system, the electronic current becomes restricted to a carbon chain running along the border with hexagonal boron nitride. This circumstance could allow the hypothetical nanodevice to become highly sensitive to the electronic nature of molecules passing through the nanopore, thus opening up ways to detect gas molecules, amino acids, or even DNA sequences based on a measurement of the real-time conductance modulation in the graphene nanoroad.
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| 4. |
- Mukhopadhyay, Saikat, et al.
(författare)
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Theoretical study of physisorption of nucleobases on boron nitride nanotubes : a new class of hybrid nano-biomaterials
- 2010
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 21:16, s. 165703-
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the adsorption of the nucleic acid bases-adenine (A), guanine (G), cytosine (C), thymine (T) and uracil (U)-on the outer wall of a high curvature semiconducting single-walled boron nitride nanotube (BNNT) by first-principles density functional theory calculations. The calculated binding energy shows the order: G > A approximate to C approximate to T approximate to U, implying that the interaction strength of the high curvature BNNT with the nucleobases, G being an exception, is nearly the same. A higher binding energy for the G-BNNT conjugate appears to result from hybridization of the molecular orbitals of G and the BNNT. A smaller energy gap predicted for the G-BNNT conjugate relative to that of the pristine BNNT may be useful in the application of this class of biofunctional materials to the design of next-generation sensing devices.
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| 5. |
- Scheicher, Ralph H., et al.
(författare)
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Theoretical study of C60 as catalyst for dehydrogenation in LiBH4
- 2011
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Ingår i: Nanotechnology. - UK : Institute of Physics. - 0957-4484 .- 1361-6528. ; 22:33
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Tidskriftsartikel (refereegranskat)abstract
- Complex light metal hydrides possess many properties which make them attractive as a storage medium for hydrogen, but typically catalysts are required to lower the hydrogen desorption temperature and to facilitate hydrogen uptake in the form of a reversible reaction. The overwhelming focus in the search for catalysing agents has been on compounds containing titanium, but the precise mechanism of their actions remains somewhat obscure. A recent experiment has now shown that fullerenes (C60) can also act as catalysts for both hydrogen uptake and release in lithium borohydride (LiBH4). In an effort to understand the involved mechanism, we have employed density functional theory to carry out a detailed study of the interaction between this complex metal hydride and the carbon nanomaterial. Considering a stepwise reduction of the hydrogen content in LiBH4, we find that the presence of C60 can lead to a substantial reduction of the involved H-removal energies. This effect is explained as a consequence of the interaction between the BHx − complex and the C60 entity.
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| 6. |
- Sivaraman, Ganesh, et al.
(författare)
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Benchmark investigation of diamondoid-functionalized electrodes for nanopore DNA sequencing
- 2016
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 27:41
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Tidskriftsartikel (refereegranskat)abstract
- Small diamond-like particles, diamondoids, have been shown to effectively functionalize gold electrodes in order to sense DNA units passing between the nanopore-embedded electrodes. In this work, we present a comparative study of Au(111) electrodes functionalized with different derivatives of lower diamondoids. Focus is put on the electronic and transport properties of such electrodes for different DNA nucleotides placed within the electrode gap. The functionalization promotes a specific binding to DNA leading to different properties for the system, which provides a tool set to systematically improve the signal-to-noise ratio of the electronic measurements across the electrodes. Using quantum transport calculations, we compare the effectiveness of the different functionalized electrodes in distinguishing the four DNA nucleotides. Our results point to the most effective diamondoid functionalization of gold electrodes in view of biosensing applications.
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