BIOMOLECULAR SENSING USING CARBON NANOTUBES: A SIMULATION STUDY

2008 ◽  
Vol 18 (04) ◽  
pp. 879-887 ◽  
Author(s):  
G.B. ABADIR ◽  
K. WALUS ◽  
R.F.B. TURNER ◽  
D.L. PULFREY
Keyword(s):  
Carbon Nanotubes ◽  
Single Molecule ◽  
Simulation Study ◽  
Density Functional ◽  
Local Density ◽  
Functional Theory ◽  
Biomolecular Sensing ◽  
The Density Functional Theory ◽  
Target Molecules ◽  
Non Equilibrium Green’S Function

A simulation study using molecular dynamics and the density-functional-theory/non-equilibrium-Green's-function approach has been carried out to investigate the potential of carbon nanotubes (CNT) as molecular-scale biosensors. Single molecules of each of two amino acids (isoleucine and asparagine) were used as the target molecules in two separate simulations. The results show a significant suppression of the local density of states (LDOS) in both cases, with a distinct response for each molecule. This is promising for the prospect of CNT-based single-molecule sensors that might depend on the LDOS, e.g., devices that respond to changes in either conductance or electroluminescence.

Effect of the vacancy on the electrical transport properties of boron nitride nanosheets

2021 ◽  
Author(s):  
Reza Sadeghi ◽  
Mojtaba Yaghobi ◽  
Mohammad Reza Niazian ◽  
Mohammad ali Ramzanpour
Keyword(s):  
Electrical Transport ◽  
Density Functional ◽  
Vacancy Defect ◽  
Defect Engineering ◽  
Electrical Transport Properties ◽  
Functional Theory ◽  
Crystalline Materials ◽  
The Density Functional Theory ◽  
Left And Right ◽  
Non Equilibrium Green’S Function

Abstract Vacancies occur naturally in all crystalline materials. A vacancy is a point defect in a crystal in which an atom is removed at one of the lattice sites. The defect could be imported during the synthesis of the material or be added by defect engineering. In this paper by employing the density functional theory as well as the non-equilibrium Green’s function approach, the structure and electronic properties of the perfect and defected BN nanosheet would be obtained and compared. Besides, the influence of the vacancy defect position is evaluated. For this purpose, the defect is considered at the center, left, and right hand sides of the nanosheet. It is seen that the electric current changes by changing the position of the vacancy defect, which is related to the electronic structures of BN nanosheets. In addition, the transmission and conductance for BN nanosheets with vacancy continuously change by changing the bias voltage. The obtained results can benefit the design and implementation of BN nanosheets in nanoelectronic systems and devices.

Studying of B, N, S, Si and P Doped (5, 5) Carbon Nanotubes by the Density Functional Theory

2012 ◽  
Vol 463-464 ◽  
pp. 1488-1492 ◽  
Author(s):  
Yan Li Wang ◽  
Ke He Su ◽  
Jun Ping Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Density Functional Theory ◽  
Density Functional ◽  
Periodic Boundary ◽  
Energy Gap ◽  
Periodic Boundary Conditions ◽  
Functional Theory ◽  
Energy Gaps ◽  
The Density Functional Theory ◽  
Metal Conductivity

The B, N, S, Si and P atoms doped single walled (5, 5) carbon nanotubes were studied by density functional theory B3LYP/3-21G (d) with the periodic boundary conditions. The ultra long tube models were calculated and the structures, energies and the band structures were obtained. The N, Si and S doped nanotubes have narrow energy gap with metal conductivity whereas B and P doped nanotubes have overlapped energy gaps with or semi-metal conductivity.

scholarly journals First-Principles Determination of the Polarizabilities of Carbon Tubules as a Function of Length

1994 ◽  
Vol 349 ◽  
Author(s):  
Andrew A. Quong ◽  
Mark R. Pederson
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Valence Electron ◽  
Local Density ◽  
Density Approximation ◽  
Functional Theory ◽  
Size Dependent ◽  
The Density Functional Theory ◽  
Linear And Nonlinear

ABSTRACTWe use the local-density-approximation to the density-functional theory to determine the axial polarizabilities of fullerene tubules as a function of length and winding topologies. Specifically, we present linear polarizabilities for tubules of composition C12H24, C36H24, C40H20 and C60H24. The size-dependent variation in the dipole-coupled gaps between pairs of occupied and unoccupied levels leads to enhancements in the polarizability per valence electron as the length of the tubule increases. The results are compared to recent densityfunctional based calculations of the linear and nonlinear polarizabilities for fullerene and benzene molecules.

scholarly journals Dopamine/2-Phenylethylamine Sensitivity of Ion-Selective Electrodes Based on Bifunctional-Symmetrical Boron Receptors

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 283 ◽  
Author(s):  
Martyna Durka ◽  
Krzysztof Durka ◽  
Agnieszka Adamczyk-Woźniak ◽  
Wojciech Wróblewski
Keyword(s):  
Single Molecule ◽  
Density Functional ◽  
Phenylboronic Acid ◽  
Dft Method ◽  
Polymeric Membranes ◽  
Ion Selective Electrodes ◽  
Functional Theory ◽  
Potentiometric Selectivity ◽  
The Density Functional Theory ◽  
Sensitivity And Selectivity

Piperazine-based compounds bearing two phenylboronic acid or two benzoxaborole groups (PBPA and PBBB) were applied as dopamine receptors in polymeric membranes (PVC/DOS) of ion-selective electrodes. The potentiometric sensitivity and selectivity of the sensors towards dopamine were evaluated and compared with the results obtained for 2-phenylethylamine. Since the developed electrodes displayed strong interference from 2-phenylethylamine, single-molecule geometry optimizations were performed using the density functional theory (DFT) method in order to investigate the origin of dopamine/2-phenylethylamine selectivity. The results indicated that phenylboronic acid and benzoxaborole receptors bind dopamine mainly through the dative B–N bond (like 2-phenylethylamine) and the potentiometric selectivity is mainly governed by the higher lipophilicity of 2-phenylethylamine.

FIRST-PRINCIPLES STUDIES ON THE ELECTRONIC STRUCTURE OF LuPd2Si2

2009 ◽  
Vol 23 (32) ◽  
pp. 5929-5934 ◽  
Author(s):  
T. JEONG
Keyword(s):  
Band Structure ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Spin Orbit Coupling ◽  
Electronic Band ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structure Scheme

The electronic band structure of LuPd 2 Si 2 was studied based on the density functional theory within local density approximation and fully relativistic schemes. The Lu 4f states are completely filled and have flat bands around -5.0 eV. The fully relativistic band structure scheme shows that spin–orbit coupling splits the 4f states into two manifolds, the 4f7/2 and the 4f5/2 multiplet.

ELECTRONIC AND DYNAMICAL PROPERTIES OF MgB2 AND RELATED COMPOUNDS

2002 ◽  
Vol 16 (11n12) ◽  
pp. 1563-1569 ◽  
Author(s):  
G. PROFETA ◽  
A. CONTINENZA ◽  
F. BERNARDINI ◽  
G. SATTA ◽  
S. MASSIDDA
Keyword(s):  
Density Functional Theory ◽  
Local Density Approximation ◽  
Density Functional ◽  
Local Density ◽  
Density Approximation ◽  
Superconducting Properties ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Dynamical Properties ◽  
Related Compounds

We report a detailed study of the electronic and dynamical properties of MgB2 , BeB2 and of the AlMgB4 superlattice, within the local density approximation to the density functional theory. On the basis of our results we discuss the superconducting properties of these systems, and point to the high T c in MgB2 as a fortunate combination of events.

Theoretical Study of Atoms Filled in Carbon Nanotubes

2016 ◽  
Vol 13 (10) ◽  
pp. 6974-6977
Author(s):  
Shuwen Cui ◽  
Weiwei Liu ◽  
Xiaosong Wang
Keyword(s):  
Carbon Nanotubes ◽  
First Principles ◽  
Density Functional ◽  
Theoretical Study ◽  
Local Density ◽  
First Principles Calculations ◽  
Functional Theory ◽  
One Dimensional ◽  
Local Density Functional Theory ◽  
Foreign Materials

The nano-sized quasi-one dimensional hollow cores of carbon nanotubes make it possible for them to be filled with and wetted by foreign materials. With C, S and Se atoms as example, we have studied the filling and wetting of these atoms into carbon nanotubes from local density functional theory in first principles calculations. The results suggest that the effect of nanotube length is negligible when it exceeds 3.6 Å, there is a relation between nanotube diameter and filling and wetting. Our studies would be important implications for the further use of carbon nanotubes.

Quadrupole polarizabilities and Sternheimer antishielding factors in the density functional theory

1982 ◽  
Vol 60 (2) ◽  
pp. 210-221 ◽  
Author(s):  
M. J. Stott ◽  
E. Zaremba ◽  
D. Zobin
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Correlation Energy ◽  
Local Density ◽  
Closed Shell ◽  
Energy Functional ◽  
Functional Theory ◽  
Hartree Fock ◽  
Shielding Factor ◽  
The Density Functional Theory

The quadrupole polarizability and Sternheimer antishielding factor have been calculated for selected closed-shell atoms and ions using the density functional theory. In most cases, the results agree favourably with coupled Hartree–Fock calculations. However, for atoms with valence (d-shells the local density approximation used in the calculations is found to be inadequate. Our results suggest that refinements to the exchange-correlation energy functional are required in order to obtain accurate values for the polarizability and shielding factor of (d-shell atoms within a density functional approach.

scholarly journals Mechanistic, energetic and structural studies of single-walled carbon nanotubes functionalized with penicillamine

2018 ◽  
Vol 83 (2) ◽  
pp. 167-179
Author(s):  
Hosein Shaki ◽  
Ali Morsali ◽  
Heidar Raissi ◽  
Mohammad Hakimi ◽  
Ali Beyramabadi
Keyword(s):  
Carbon Nanotubes ◽  
Density Functional ◽  
Activation Parameters ◽  
Covalent Functionalization ◽  
Functional Theory ◽  
Quantum Molecular Descriptors ◽  
Chemical Systems ◽  
Gibbs Energies ◽  
The Density Functional Theory ◽  
Walled Carbon Nanotubes

Using the density functional theory, the possible non-covalent interactions and six mechanisms of covalent functionalization of the drug penicillamine with functionalized carbon nanotubes (CNT) were investigated. Quantum molecular descriptors of the non-covalent configurations were studied. It was determined that binding of the drug penicillamine with functionalized CNT is thermodynamically viable. COOH functionalized CNT (NTCOOH) has more binding energy than COCl functionalized CNT (NTCOCl) and could act as a favorable system for penicillamine drug delivery within biological and chemical systems (non-covalent). NTCOOH and NTCOCl can bond to the NH2, OH and SH groups of penicillamine through OH (COOH mechanism) and Cl (COCl mechanism) groups, respectively. The activation energies, activation enthalpies and activation Gibbs energies of six pathways were calculated and compared with each other. The activation parameters related to the COOH mechanism are higher than those related to the COCl mechanism and therefore, the COCl mechanism is suitable for covalent functionalization. These results could be generalized to other similar drugs.

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