Dissimilar metal electrodes in molecular junction play significant role in exploring the intriguing properties of biomolecules. One such property is rectification ratio, which ensures the candidature ...of different biomolecules as nanoelectronics devices. Protein based nanoelectronics devices are gaining enduring attention among researchers working in the field of bio nanotechnology. The alluring properties of proteins can be predicted if the subunit i.e. amino acids be explored individually. With the aim of exploring amino acid based nanoelectronics devices, we consider the negatively charged amino acid (i.e., L-Glutamic acid, (C5H9NO4)) with dissimilar metal electrodes on either side, forming Au-Glutamic-Ag, Au-Glutamic-Cu and Ag-Glutamic-Cu molecular junctions. The first-principle calculations are performed using Density functional theory in local density approximations (DFT-LDA). The molecule with dissimilar electrodes offers dissimilar rectification ratio and finite negative differential resistance. The Au-Glutamic-Cu molecular device exhibits highest while Ag-Glutamic-Cu exhibits the lowest zero bias conductance values. Higher rectification ratio and lower Homo-Lumo gap is observed with Au-Glutamic-Cu and Au-Glutamic-Ag molecular devices. Such investigation highlights the prospect of L-Glutamic acid like biomolecules for future nanoelectronic devices.
The electron transport properties of shorter peptides (i.e., dipeptides) consisting of oppositely charged amino acids have paved the way for the design of miniaturized molecular devices. In this ...context, we investigated two different dipeptides, namely arginyl-aspartic and arginyl-glutamic, alternating between one positively charged (i.e.,
l
-arginine) and two negatively charged (i.e.,
l
-aspartic and
l
-glutamic) amino acids. These dipeptides are placed between Au, Ag and Cu electrodes to form a total of six individual molecular devices. Various transport parameters including conductance, HOMO-LUMO gap, dipole moment, current–voltage (I–V) characteristics, rectification ratio and negative differential resistance regimes are computed using density functional theory with non-equilibrium Green’s function (NEGF-DFT). We observe an exceptionally high rectification ratio of 197.2 with the Au-Arg-Asp-Au device, while the Au-Arg-Glu-Au device offers the most significant negative differential resistance (NDR) regime, with a peak-to-valley current ratio of 178.9. We focus on the standard electron exchange–correlation integration of the Perdew–Burke–Ernzerhof (PBE) generalized gradient approximation (GGA) with the double-zeta double-polarized (DZDP) basis set. The conductance, transmission spectra, delocalization of significant frontier orbitals and their gap correlate well with the switching characteristics. The coupling between molecule and electrode predicts the range of I–V characteristics. These results reveal the significant role of dipeptides in future molecular electronic devices.
Graphical Abstract
The conductance of a single molecule transport junction comprising anthracene molecular junction (AMJ) with fullerene as alligator clips was investigated using
ab-initio
density functional theory ...(DFT) in the Landauer–Imry regime of coherent tunnelling transport. In our previous research, we have already calculated the electrical transport properties of aromatic molecules with thiol, amine, hydroxyl and selenol end groups concluding the exceptional assistance in the formation of robust molecular junctions. In this article, we have presented the suitability of fullerene anchoring in coupling anthracene molecule with gold electrodes. AMJ with boron-20 (B-20) and C-20 alligator clips exhibited strongest conduction in contrast to nitrogen, oxygen, fluorine and neon alligator clips.
L-Histidine (C
6
H
9
N
3
O
2
), one of the most prominent positively charged amino acids, has shown a lot of potential as a future molecular device. A subcomponent of proteins, L-Histidine has been ...acknowledged for its applications in designing future switching devices and logic gates. Interpreting its transport parameters while aligning it as a central molecule with a series of metallic electrodes using a self-consistent function and implementing the density functional theory and non-equilibrium Green’s function (NEGF-DFT) approach for our computational analysis, we observe that the proposed devices exhibit dissimilar rectification ratios (RR), besides demonstrating negative differential resistance (NDR) regimes. The RRs of DFT-D3 corrected and the uncorrected molecular device is also compared to verify the impact of van der Waals (vdW)-type interaction on current–voltage characteristics. The molecular device with copper electrodes yields the maximum rectification ratio of 8.1, while the device with palladium electrodes yields the highest peak-to-valley current ratio of 1.28. Such a study proffers the idea of choosing proper electrodes for exploring the rectification ratio of biomolecules. Moreover, using these L-Histidine-based molecular devices, we have proposed AND Logic gate and OR Logic gate, which can pave the way to an alternate research area of using peptides as future molecular devices.
A novel garlic tunic (waste biomaterial) and its composite-based organic green electrical energy generation device are fabricated in this study. This device will eliminate the need of batteries for ...small electronic/medical devices and the e-waste of used batteries will be reduced, as per the UN’s Sustainable Development Goal 7 (affordable and clean energy). Garlic tunic (GT) is a naturally occurring waste biomaterial that is not edible and thrown away. The electrical energy generation performance of GT is altered by synthesizing its composite with tin oxide(II) (SnO) nanoparticles, and a triboelectric nanogenerator is fabricated from the synthesized composite. GT/SnO-based device performance is also tested with other biomaterials such as egg shell membrane, onion tunic, almond peel, Bombax ceiba fibers, and Calotropis fibers. The formation of SnO nanoparticles in a composite is validated using different characterization techniques. X-ray diffraction analysis confirmed the presence of SnO nanoparticles having a space group of P4/nmm and a crystallite size of 22 nm. Scanning electron microscopy images reflected the growth of spherical-shaped nanoparticles with a particle size of 56 nm. The fabricated device produces power from human motions such as walking, running, and jumping and also from manual tapping to drive 30 green light-emitting diodes and a small digital wrist watch.
Since the beginning of this decade, there has seen an exponential growth in number of internet users using social media, especially Twitter for sharing their views on various topics of common ...interest like sports, products, politics etc. Due to the active participation of large number of people on Twitter, huge amount of data (i.e. big data) is being generated, which can be put to use (after refining) to analyze real world problems. This paper takes into consideration the Twitter data related to the 2017 Punjab (a state of India) assembly elections and applies different social media analytic techniques on collected tweets to extract and unearth hidden but useful information. In addition to this, we have employed machine learning algorithm to perform polarity analysis and have proposed a new seat forecasting method to accurately predict the number of seats that a political party is likely to win in the elections. Our results confirmed that Indian National Congress was likely to emerge winner and that in fact was the outcome, when results got declared.
•We present a genuine method for predicting election results using social media.•We demonstrate that Twitter is a useful tool for electoral forecasting.•Our forecast not only predicts the vote share but also the seat share.•Our forecast accurately predicts the seat share of top three parties.
The integrants of proteins, i.e., amino acids, have grossed exceptional recognition for their applications towards designing imminent switching devices. Among 20 amino acids, L-Lysine (i.e., ...positively charged) has the highest number of CH
2
chains, and such chains affect the rectification ratio in several biomolecules. Towards molecular rectification, we investigate the transport parameters of L-Lysine in conjunction with five different coinage metal electrodes, i.e., Au, Ag, Cu, Pt and Pd to form five distinct devices. We deputize the NEGF-DFT formulism for computing conductance, frontier molecular orbitals, current–voltage, and molecular projected self-Hamiltonian calculations using a self-consistent function. We focus on the most widely used electron exchange correlation combination, i.e., the PBE version of GGA with DZDP basis set. The molecular devices under inquisition exhibit phenomenal rectification ratios (RR) in conjunction with negative differential resistance (NDR) regimes. The nominated molecular device offers a substantial rectification ratio of 45.6 with platinum electrodes and a prominent peak to valley current ratio of 1.78 with copper electrodes. We deduce from these findings that L-Lysine based molecular devices would implicit in future bio-nanoelectronic devices. The OR and AND logic gates are also proposed hinged on highest rectification ratio of L-Lysine-based devices.
Protein-based electronics is one of the growing areas of bio-nanoelectronics, where novel electronic devices possessing distinctive properties are being fabricated using specific proteins. ...Furthermore, if the bio-molecule is analysed amidst different electrodes, intriguing properties are elucidated. This research article investigates the electron transport properties of
l
-aspartic acid (i.e.
l
-amino acid) bound to symmetrical electrodes of gold, silver, copper, platinum and palladium employing NEGF-DFT approach using self-consistent function. The theoretical work function of different electrodes is calculated using local density approximation and generalized gradient approximation approach. The calculated work function correlates well with the hole tunneling barrier and conductance of the molecular device, which further authenticate the coupling strength between molecule and electrode. Molecule under consideration also exhibits negative differential resistance region and rectification ratio with all the different electrodes, due to its asymmetrical structure. The molecular device using platinum electrodes exhibits the highest peak to valley ratio of 1.38 and rectification ratio of 3.20, at finite bias. The switching characteristics of different molecular device are justified with detailed transmission spectra and MPSH. These results indicate that
l
-aspartic acid and similar biomolecule can be vital to the growth of Proteotronics.
A computational study is carried out on thymine using the two-probe method. A thymine molecule with thiol anchors is sandwiched between two gold electrodes having crystallographic orientation. The ...electrical transport characteristics are analyzed using the extended Hückel theory with two-dimensional (2D) fast Fourier transform (FFT) computations to understand the use of thymine in the design of memory devices and logic gates. The temperature is taken to be 300 K, with a mesh cutoff value of 75 Hartree. A linear
I
–
V
characteristic is obtained for higher values of the current for the thymine-based device. This can be explained based on the strong coupling of the molecule with the gold electrodes in the scattering region. Moreover, the rectification ratio at 2 V and 1 V is applied to design an AND and OR gate, respectively. Furthermore, a memory device based on these gates is demonstrated. The results indicate that such molecular devices based on one of the bases of DNA (thymine) may have possible applications in electronic devices, thereby enabling further miniaturization of electronic circuits.
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