Green Phosphorene as a Promising Biosensor for Detection of Furan and p-Xylene as Biomarkers of Disease: A DFT Study

Comparative Analysis of the Hydrazine Interaction with Arylene Diimide Derivatives: Complementary Approach Using First Principles Calculation and Experimental Confirmation

Suitable functional group-engineered π-conjugated aromatic dimides based on perylene (PDI) and naphthyl scaffolds (NDI) demonstrated excellent sensitivity toward different gaseous analytes. However, to date, no methodical analysis has been performed to rationalize molecular-level interactions in the context of optical transduction, which is essential for systematic performance optimization of NDI/PDI-based molecular sensors. Therefore, in this present work, NDI/PDI scaffolds have been designed with amino acid functional groups (alanine, ALA and glutamic acid, GLU) at the terminal positions, and we subsequently compared the efficacy of four different imide derivatives as model hosts for hydrazine adsorption. Specifically, the adsorption of hydrazine at different interaction sites has been thoroughly investigated using ab initio calculations, where the adsorption energy, charge transfer, and recovery time have been emphasized. Theoretical results exhibit that irrespective of host specification the COOH groups offer a primary interaction site for hydrazine through the hydrogen bonding interaction. The presence of more COOH groups and relatively stronger interaction with secondary edge oxygen ensure that GLU functional moieties are a superior choice over ALU for efficient hydrazine binding. The molecular energy spectrum analysis exhibits more favorable HOMO/LUMO gap variations after hydrazine interaction in the case of PDI derivatives irrespective to the nature of the amino acid residues. Therefore, by a combination of both factors, PDI-GLU has been identified as the most suitable host molecule for hydrazine among four derivatives. Finally, the key theoretical predictions has been later experimentally validated by analyzing UV-visible spectroscopy and NMR studies, wherein the mechanism of interaction has also been experimentally verified by EPR analysis and FT-IR studies.

Cobalt group transition metals (TM: Co, Rh, Ir) coordination of S-doped porphyrins (TM_S@PPR) as sensors for molecular SO2 gas adsorption: a DFT and QTAIM study

CONTEXT

The intricate challenges posed by SO2 gas underscore the imperative for meticulous monitoring and detection due to its adverse effects on health, the environment, and equipment integrity. Hence, this research endeavors to delve deeply into the intricate realm of transition-metals functionalized sulfur-doped porphyrins (S@PPR) surfaces through a comprehensive computational study. The electronic properties revealed that upon adsorption, Ir_S@PPR surface reflects the least energy gap of 0.109 eV at the O-site of adsorptions, indicating an increase in electrical conductivity which is a better adsorption trait. Owing to the negative adsorption energy observed, the adsorption behavior is described as chemisorption, with the greatest adsorption energy of - 10.306 eV for Ir_S@PPR surface at the S-site of adsorption. Based on the mechanistic attributes, iridium-functionalized S@PPR surface is a promising detecting material towards the sensing of SO2 gas. This report will provide useful insight for experimental researchers in selecting and engineering materials to be used as detectors for SO2 gas pollutant.

METHOD

All theoretical investigations were carried out using density functional theory (DFT), calculated at PW6B95-D3/GenECP/Def2svp/LanL2DZ computational method.

Tuning phosphorene and MoS2 2D materials for detecting volatile organic compounds associated with respiratory diseases

Efficient identification of volatile organic compounds (VOCs) is essential for the rapid diagnostication of respiratory diseases. By detecting specific biomarkers associated with different pathologies one may distinguish between tuberculosis, nosocomial pneumonia, Aspergillus fumigatus, influenza and SARS-CoV-2 virus infections. Phosphorene and MoS2 are potential candidates from the class of 2D graphene-like materials, which can be used as active layers for sensing elements. However, as the target molecules poorly adhere to the pristine layers, binding centers are created by introducing substitutional impurities. The adsorbed VOCs induce modifications in the electrical properties of the customized active layers. For each biomarker and a sequence of substitutional impurities, a pattern of conductivities is obtained, which enables the detection of an unknown test specimen. Exploring multiple biosensor configurations we find an optimal design yielding a considerable selectivity for the five biomarker compounds.

Investigation of the Multimechanism Laser Cleaning Dynamics for Rough Fused Silica Surfaces with Organic Contaminants: A Computational Simulation and Atomic Analysis

The detrimental impact of organic contaminants on optical components poses a significant obstacle to high-energy laser systems. However, irregularities or defects on the surface of optical components during manufacturing can affect the process of organic contaminant removal. Thus, a comprehensive understanding of the intricate interplay among surface roughness, contaminant absorption, and ablation is essential to effectively address the challenges of laser-induced damage. In this study, a molecular dynamics approach was employed to investigate the interaction between laser-fused silica and contaminants and to analyze the influence of surface roughness on the removal of contaminants from fused silica. Research findings demonstrate that during laser irradiation, organic contaminants on the surface of mechanical components diffuse into the optical elements. As the laser flux increases, the contaminants gradually decompose into smaller molecular clusters. Additionally, the phenomenon of contaminant ablation is observed to consist of two distinct phases: the "Thermal expansion phase" and the "Thermal ablation phase." The study examines the impact of substrate roughness on the contaminant removal in these two phases. It is found that a higher surface roughness leads to stronger thermal expansion and vaporization of contaminants. With increasing roughness of the fused silica substrate, the corresponding van der Waals energy and pressure decrease under the same laser fluence, making the removal of contaminants easier. These results provide valuable insights into the interaction between laser irradiation and organic contaminants.

Quantum chemical investigation of Z-shaped heptazethrenes derivatives with detailed structural parameters and singlet fission for photovoltaic applications

A variety of organic solar cells has been discovered, but there is a need for efficient optoelectronic material to obtain high power conversion efficiency. In this study, we derived new molecules from Z-shaped heptazethrene. We measured its photovoltaic parameters, including frontier molecular orbitals (where the energy gap decreases to 16% as compared to the reference), molecular electrostatic potential maps (more nucleophilic core), the density of states (partial and total), absorbance in Vis-IR region (in the range of 650-1000 nm), transition density matrix, and hole-electron mobility in terms of reorganization energy that showed 11% higher electron mobility (λ_e) and 52% higher hole mobility (λ_h) as compared to the reference. A comparable power conversion efficiency (∼9%) is obtained from a single photon. Using the concept of singlet fission, we can increase the efficiency twice using a single photon (based on the diradical character of the molecule). The diradical character of the entitled molecules was also calculated. The designed molecules fulfil the criteria of singlet fission that generate two excited triplets from a single photon (E_S1>2E_T1). The designed molecules are more stable than the reference indicated by the singlet-triplet energy gap, which is 37% higher. Hence this work assists the researcher in enhancing the efficiency of the solar cell.