Interaction studies of dichlobenil and isoproturon on square-octagon phosphorene nanotube based on DFT frame work

Unraveling the influence of defects on Sulfonamide adsorption onto Blue-phosphorene nanotube using density functional theory

Sulfonamide antibiotics are commonly used in human therapy. Consequently, pharmaceutical residues may seep into the surface and groundwater, contaminating the aquatic environment. Adsorption is the most widely used method for removing these contaminants from water bodies. This study investigates the efficiency of (14, 14) armchair and (14, 0) zigzag blue phosphorene-based nanotubes (BPNT) as adsorbents of three popular toxic antibiotics, Sulfanilamide (SAM), Sulfadimethoxine (SMX), and Sulfadiazine (SDZ), from water bodies. All calculations are performed using density functional theory. Analyzed molecules are weakly adsorbed on the pristine BPNTs with an adsorption energy of about -0.312, -0.285, and -0.377 eV. Further, electronic properties of the antibiotics-adsorbed BPNTs are investigated. The effect of single-vacancy BPNTs on the adsorption affinity of antibiotic molecules was studied. Compared with pristine systems, despite the increase in reactivity of zigzag BPNTs to the sulfonamides, armchair configurations show a transition from bipolar-magnetic semiconductor to a non-magnetic metallic system, suggesting that defective armchair BPNTs can also be employed as a sensor for antibiotic molecules. Single-vacancies increase the [Formula: see text] values of all studied systems by up to 89%, indicating an improvement in the capacity of BPNTs to adsorb these biologically active sulfonamide-based compounds.

Magnetic ε-Phosphorene for Sensing Greenhouse Gas Molecules

It is critical for gas sensors that sense greenhouse gas molecules to have both good sensitivity and selectivity for water molecules in the ambient environment. Here, we study the charge transfer, IV curves, and electric field tuning of vanadium-doped monolayer ϵ-phosphorene as a sensor for NO, NO₂, and H₂O gas molecules via first-principle and transport calculations. We find that the paramagnetic toxic molecules of NO and NO₂ have a high adsorption energy on V-ϵ-phosphorene, which originates from a large amount of charge transfer driven by the hybridisation of the localised spin states of the host with the molecular frontier orbital. Using the non-equilibrium Green's function, we investigate the IV responses with respect to the adsorption of different molecules to study the performance of gas molecule sensors. Our IV curves show a larger amount of changes in resistance of the paramagnetic NO and NO₂ than nonmagnetic H₂O gas molecules, suggesting both sensitivity and selectivity. Moreover, our calculations show that an applied external electric field (gate voltage) can effectively tune the amount of charge transfer. More charge transfer makes the sensor more sensitive to the molecule, while less charge transfer can reduce the adsorption energy and remove the adsorbed molecules, allowing for the repeated use of the sensor.

On the possibility of using the Ti@Si16 superatom as a novel drug delivery carrier for different drugs: A DFT study

The potential application of an experimentally synthesized superatom Ti@Si₁₆ as a novel drug carrier for cisplatin (DDP), isoniazid (INH), acetylsalicylic acid (ASA), 5-fluorouracil (5-Fu), and favipiravir (FPV) has been explored by density functional theory. It is observed that the Pt atom of DDP can be effectively absorbed on Ti@Si₁₆ via a "donation-back donation" electron transfer mechanism, resulting in a moderate adsorption energy of -19.95 kcal/mol for DDP@[Ti@Si₁₆]. As for INH, it prefers to combine with Ti@Si₁₆ via the N atom of pyridine ring by forming a strongly polar N-Si bond. Differently, the interaction between Ti@Si₁₆ and the ASA, 5-Fu, and FPV drugs is dominated by the Van der Waals interaction. Our results reveal that DDP@[Ti@Si₁₆] possesses a moderate recovery time under body temperature, which benefits the desorption of DDP from Ti@Si₁₆. More importantly, the release of DDP drug from the Ti@Si₁₆ surface can be effectively controlled by exerting small orientation external electric fields on the DDP@[Ti@Si₁₆] complex. Therefore, this study demonstrates that Ti@Si₁₆ can serve as a promising drug carrier for DDP, and thus will further expand its practical applications in the biomedical field.

Twisted bilayer arsenene sheets as a chemical sensor for toluene and M-xylene vapours - A DFT investigation

2D (two-dimensional) materials are emerging in today's world. Among the 2D materials, arsenene sheets are prominently used as chemical and biosensors. In the present work, the twisted bilayer arsenene sheets (TB-AsNS) are used to adsorb toluene and M-xylene vapours. Moreover, the band gap of pristine TB-AsNS is calculated to be 0.437 eV. Besides, the surface adsorption of toluene and M-xylene vapours modify the electronic properties of TB-AsNS noticed from the band structure, density of states, and electron density difference diagrams. The surface assimilation of target toluene and M-xylene on TB-AsNS falls in the physisorption regime facilitating the adsorption and desorption of molecules. Also, the charge transfer analysis infers that TB-AsNS acts as acceptor and target molecules play as donors. The findings support that TB-AsNS can be used as a sensing medium towards M-xylene and toluene.