DFT study on CO 2 capture using boron, nitrogen, and phosphorus-doped C 20 in the presence of an electric field.

Burning fossil fuels emits a significant amount of CO 2 , causing climate change concerns. CO 2 Capture and Storage (CCS) aims to reduce emissions, with fullerenes showing promise as CO 2 adsorbents. Recent research focuses on modifying fullerenes using an electric field. In light of this, we carried out DFT studies on some B, N, and P doped C 20 ( C 20 - n X n , n = 0, 1, 2, and 3; X = B, N, and P) in the absence and presence of an electric field in the range of 0-0.02 a.u.. The cohesive energy was calculated to ensure their thermodynamic stability showing, that despite having lesser cohesive energies than C 20 , they appear in a favorable range. Moreover, the charge distribution for all structures was depicted using the ESP map. Most importantly, we evaluated the adsorption energy, height, and CO 2 angle, demonstrating the B and N-doped fullerenes had the stronger interaction with CO 2 , which by far exceeded C 20 's, improving its physisorption to physicochemical adsorption. Although the adsorption energy of P-doped fullerenes was not as satisfactory, in most cases, increasing the electric field led to enhancing CO 2 adsorption and incorporating chemical attributes to CO 2 -fullerene interaction. The HOMO-LUMO plots were obtained by which we discovered that unlike the P-doped C 20 , the surprising activity of B and N-doped C 20 s against CO 2 originates from a high concentration of the HOMO-LUMO orbitals on B, N and neighboring atoms. In the present article, we attempt to introduce more effective fullerene-based materials for CO 2 adsorption as well as strategies to enhance their efficiency and revealing adsorption nature over B, N, and P-doped fullerenes and in the end, hope to encourage more experimental research on these materials within growing electric field for CO 2 capture in the future.

Ionome mapping and amino acid metabolome profiling of Phaseolus vulgaris L. seeds imbibed with computationally informed phytoengineered copper sulphide nanoparticles.

This study reports the effects of a computationally informed and avocado-seed mediated Phyto engineered CuS nanoparticles as fertilizing agent on the ionome and amino acid metabolome of Pinto bean seeds using both bench top and ion beam analytical techniques. Physico-chemical analysis of the Phyto engineered nanoparticles with scanning-electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier Transform Infrared Spectroscopy confirmed the presence of CuS nanoparticles. Molecular dynamics simulations to investigate the interaction of some active phytocompounds in avocado seeds that act as reducing agents with the nano-digenite further showed that 4-hydroxybenzoic acid had a higher affinity for interacting with the nanoparticle's surface than other active compounds. Seeds treated with the digenite nanoparticles exhibited a unique ionome distribution pattern as determined with external beam proton-induced X-ray emission, with hotspots of Cu and S appearing in the hilum and micropyle area that indicated a possible uptake mechanism via the seed coat. The nano-digenite also triggered a plant stress response by slightly altering seed amino acid metabolism. Ultimately, the nano-digenite may have important implications as a seed protective or nutritive agent as advised by its unique distribution pattern and effect on amino acid metabolism.

Theoretical study of chemical reactivity descriptors of some repurposed drugs for COVID-19.

This study focuses on computational studies of chemical reactivity descriptors of some proposed drugs for COVID-19. Density functional theory calculations were used to optimize the structure and investigate the frontier orbitals and the chemical reactivity descriptors of these drugs. The frontier orbitals, which include both the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), play an essential role in molecular interactions and chemical reactivity of molecule. Polarizability, which determines the response of the susceptibility of a molecule to an approaching charge, is higher in the more complex drugs such as Hydroxychloroquine, Remdesivir, and Ivermectin compare to the smaller drugs. The HOMO and LUMO orbital energies were calculated to obtain the energy gap of the studied drugs, which is in the following order: Favipiravir < Hydroxychloroquine, Remdesivir < Ivermectin < Artesunate < Artemether < Artemisinin. Generally, molecules with a larger energy gap have lower chemical reactivity and higher kinetic stability.

Toward visual chiral recognition of amino acids using a wide-range color tonality ratiometric nanoprobe.

Chiral recognition has long been a challenging issue to deal with in biological systems, drug design and food authentication. Implementing nanoparticle-based probes with intrinsic or induced chirality in this field has addressed several issues concerning sensitivity, reliability, rapidness and the cost of chiral sensing platforms. Yet, research into chiral nanoprobes that can be used for visual monitoring of chiral substances is still in its infancy. As part of this study, a visual chiral recognition platform has been developed in which a combination of blue-emitting carbon dots (BCDs) and mercaptopropionic acid-capped CdTe quantum dots (MPA-QDs) with inherent chiroptical activity were employed for enantiomeric detection. The ratiometric probe displayed unique fluorescence response patterns in the presence of arginine (Arg) and histidine (His) enantiomers. Upon addition of l-amino acids, successive enhancement and quenching of emission intensity as well as a red-shift in emission wavelength of MPA-QDs were observed. The emission color of the nanoprobe changed from green to pink-red and green to brick-red red by increasing the concentration of L-Arg and L-His, respectively. In contrast, their d-amino acid equivalents have a negligible influence on the emission color and fluorescence signal of the developed nanoprobe. Due to the enantioselective vibrant color changes of the nanoprobe, RGB analysis was applied for the determination of enantiomeric excess (ee) in racemic mixture with satisfactory results, allowing smartphone-based onsite visual evaluation of ee (%). Circular dichroism, lifetime, size distribution and ζ-potential measurements were employed to study the chiroselective responses. First-principle calculations were also carried out with density functional theory (DFT) to confirm the experimental observation. Furthermore, chiroselective response patterns of the ratiometric nanoprobe were manipulated to construct a logic gate system mimicking AND, OR, and INHIBIT functions. The capability of the proposed chiral platform in visual monitoring of the fraction of enantiomers in racemic mixtures has a great potential for rapid and onsite visual discrimination of chiral compounds in the field of clinical diagnostics and drug analysis.

Comparing the nature of quantum plasmonic excitations for closely spaced silver and gold dimers.

In the new field of quantum plasmonics, plasmonic excitations of silver and gold nanoparticles are utilized to manipulate and control light-matter interactions at the nanoscale. While quantum plasmons can be described with atomistic detail using Time-Dependent Density Functional Theory (DFT), such studies are computationally challenging due to the size of the nanoparticles. An efficient alternative is to employ DFT without approximations only for the relatively fast ground state calculations and use tight-binding approximations in the demanding linear response calculations. In this work, we use this approach to investigate the nature of plasmonic excitations under the variation of the separation distance between two nanoparticles. We thereby provide complementary characterizations of these excitations in terms of Kohn-Sham single-orbital transitions, intrinsic localized molecular fragment orbitals, scaling of the electron-electron interactions, and probability of electron tunneling between monomers.

First principle simulation of coated hydroxychloroquine on Ag, Au and Pt nanoparticles.

From the first month of the COVID-19 pandemic, the potential antiviral properties of hydroxychloroquine (HCQ) and chloroquine (CQ) against SARS-CoV-2 suggested that these drugs could be the appropriate therapeutic candidates. However, their side effects directed clinical tests towards optimizing safe utilization strategies. The noble metal nanoparticles (NP) are promising materials with antiviral and antibacterial properties that can deliver the drug to the target agent, thereby reducing the side effects. In this work, we applied both the quantum mechanical and classical atomistic molecular dynamics approaches to demonstrate the adsorption properties of HCQ/CQ on Ag, Au, AgAu, and Pt nanoparticles. We found the adsorption energies of HCQ/CQ towards nanoparticles have the following trend: PtNP > AuNP > AuAgNP > AgNP. This shows that PtNP has the highest affinity in comparison to the other types of nanoparticles. The (non)perturbative effects of this drug on the plasmonic absorption spectra of AgNP and AuNP with the time-dependent density functional theory. The effect of size and composition of NPs on the coating with HCQ and CQ were obtained to propose the appropriate candidate for drug delivery. This kind of modeling could help experimental groups to find efficient and safe therapies.

First principle study of silver nanoparticle interactions with antimalarial drugs extracted from Artemisia annua plant.

Silver nanoparticles have a great potential in a broad range of applications such as drug-delivery carriers because of their antiviral and antibacterial properties. In this study, the coating properties of silver nanoparticle (size range of 1.6 nm) with three common anti-malarial drugs, Artemisinin, Artemether, and Artesunate have been studied by using the quantum mechanical and classical atomistic molecular dynamics simulation in order to use as the drug delivery to treat malaria and COVID-19 diseases. The optimized structure, frequencies, charge distribution, and the electrostatic potential maps of the three drug molecules were simulated by using the density functional theory (DFT) at the B3LYP/6-311++g(d,p) level of theory. Then, molecular dynamics simulation was used to study the coating of AgNP with each of these drugs. The affinity of interaction was obtained as Artesunate > Artemether > Artemisinin which is in agreement with the DFT results on the adsorption of drugs on the Ag(111) slab.