School Of Basic And Applied Sciences
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Item Probing interaction of atherogenic lysophosphatidylcholine with functionalized graphene nanosheets: theoretical modelling and experimental validation(Springer Science and Business Media Deutschland GmbH, 2023-09-09T00:00:00) Panigrahi, Abhishek R.; Yadav, Pooja; Beura, Samir K.; Singh, Jyoti; Dastider, Saptarshi G.; Singh, Sunil K.; Mondal, KrishnakantaContext: The potential of graphene derivatives for theranostic applications depends on their compatibility with cellular and biomolecular components. Lysophosphatidylcholine (LPC), a lipid component present in oxidized low-density lipoproteins, microvesicles and free circulation in blood, plays a critical role in the pathophysiology of various diseases. Using�density functional theory-based methods, we systematically investigated the interaction of atherogenic LPC molecule with different derivatives of graphene, including pristine graphene, graphene with defect, N-doped graphene, amine-functionalized graphene, various graphene oxides and hydroxylated graphene oxides. We observed that the adsorption of LPC on graphene derivatives is highly selective based on the orientation of the functional groups of LPC interacting with the surface of the derivatives. Hydroxylated graphene oxide exhibited the strongest interaction with LPC with adsorption energy of ? 2.1 eV due to the interaction between the hydroxyl group on graphene and the phosphate group of LPC. The presence of aqueous medium further enhanced this interaction indicating favourable adsorption of LPC and graphene oxide in biological systems. Such strong interaction leads to substantial change in the electronic structure of the LPC molecule, which results in the activation of this molecule. In contrast, amine-modified graphene showed the least interaction. These theoretical results are in line with our experimental fluorescence spectroscopic data of LPC/1-anilino-8-napthalene sulfonic acid complex. Our present comprehensive investigation employing both theoretical and experimental methods provides a deeper understanding of graphene-lipid interaction, which holds paramount importance in the design and fabrication of graphene-based nanomaterials for biomedical applications. Methods: In this study, we employed the density functional theory-based methods to investigate the electronic and structural properties of graphene derivatives and LPC molecule using the Quantum Espresso package. The exchange�correlation functional was described within generalized gradient approximation (GGA) as parameterized by Perdew, Burke and Ernzerhof (PBE). The valence electrons were represented using plane wave basis sets. `The Grimme�s dispersion method was used to include the van der Waals dispersion correction. � 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Item Enhanced photocatalytic activity of BiOBr/ZnWO4 heterojunction: A combined experimental and DFT-based theoretical approach(Elsevier B.V., 2023-03-28T00:00:00) Andrade, Alana O.C.; Lacerda, Lu�s Henrique da Silveira; Lage J�nior, M.M.; Sharma, Surender K.; Maia da Costa, M.E.H.; Alves, Odivaldo C.; Santos, Evelyn C.S.; dos Santos, C.C.; de Menezes, A.S.; San-Miguel, Miguel Angel; Filho, Francisco Moura; Longo, Elson; Almeida, Marcio A.P.We report a successful fabrication of BiOBr/ZnWO4 heterojunction with enhanced photocatalytic performance for degrading Rhodamine B dye validated by joint experimental and theoretical approaches. The structural and microstructural analysis indicate that the heterostructures consist of a mixed tetragonal/monoclinic phase with enhanced surface area, which is crucial for photocatalysis. The results indicate increased photocatalytic activity for heterojunctions since BiOBr/ZnWO4 heterostructure showed a better degradation rate for Rhodamine B dye as compared to BiOBr due to higher surface area, pore size, and better photogenerated electron-hole pair separation efficiency. Additional analyses using isopropanol, benzoquinone, and sodium azide scavengers analysis were performed, showing that superoxide radicals (O2?) as the main responsible for the photocatalytic degradation of investigated materials. The theoretical analysis offers a complete overview of the composition and electronic structure of the interface. � 2023 Elsevier B.V.Item Adsorption and activation of CO2 on a Au19Pt subnanometer cluster in aqueous environment(Elsevier B.V., 2022-04-15T00:00:00) Mondal, Krishnakanta; Megha; Banerjee, Arup; Fortunelli, AlessandroWe employ ab initio density functional theory based method to investigate the ability of a subnanometer bimetallic Au19Pt cluster to adsorb and activate a CO2 molecule in an aqueous electrochemical environment. We find that, in water, Au19Pt gets negatively charged at zero bias and selectively promotes the adsorption and activation of the CO2 molecule via electron transfer and through the hybridization of oxygen p-orbitals and partially filled platinum d-orbitals. Notably, Pt acts as a collector of negative charge and behaves as a CO2-activating single-atom catalyst embedded within a robust Au20-like framework, thus suggesting Au19Pt as a potential candidate for CO2 mitigation. � 2022 Elsevier B.V.Item Optoelectronic and photocatalytic properties of stable pentagonal B2S and B2Se monolayers(Elsevier B.V., 2022-06-01T00:00:00) Katoch, Neha; Kumar, Jagdish; Kumar, Ashok; Ahluwalia, P.K.; Pandey, RavindraBoron-based 2D monolayers have attracted tremendous interest due to their unique physical and chemical properties. In this paper, we report novel pentagonal monolayers, B2S and B2Se, which are predicted to be energetically, dynamically, and thermally stable based on density functional theory. At the HSE06 level of theory, they exhibit a moderate indirect bandgap of (e.g., 1.82 eV for Penta-B2S and 1.94 eV for Penta-B2Se). Strain-induced indirect-to-direct bandgap transition, high hole mobility (~103 Cm2V-1S-1) and strong optical absorption (? ~105 Cm-1) in the visible region are observed for these monolayers. Moreover, the electronic band structures and optical spectra are tunable by mechanical strains suggesting their visible light-harvesting capabilities for optoelectronic applications. In this way, the pentagonal family of 2D materials is now expanded to include boron-containing photocatalytic materials for water splitting applications. � 2022Item Electronic and optical properties of boron-based hybrid monolayers(IOP Publishing Ltd, 2021-06-24T00:00:00) Katoch, Neha; Kumar, Ashok; Kumar, Jagdish; Ahluwalia, P.K.; Pandey, RavindraAnisotropic 2D Dirac cone materials are important for the fabrication of nanodevices having direction-dependent characteristics since the anisotropic Dirac cones lead to different values of Fermi velocities yielding variable carrier concentrations. In this work, the feasibility of the B-based hybrid monolayers BX (X = As, Sb, and Bi), as anisotropic Dirac cone materials is investigated. Calculations based on density functional theory and molecular dynamics method find the stability of these monolayers exhibiting unique electronic properties. For example, the BAs monolayer possesses a robust self-doping feature, whereas the BSb monolayer carries the intrinsic charge carrier concentration of the order of 1012 cm?2 which is comparable to that of graphene. Moreover, the direction-dependent optical response is predicted in these B-based monolayers; a high IR response in the x-direction is accompanied with that in the visible region along the y-direction. The results are, therefore, expected to help in realizing the B-based devices for nanoscale applications. � 2021 IOP Publishing Ltd Printed in the UKItem Precisely designed oxazolonaphthoimidazo[1,2-a]pyridine-based sensor for the detection of Fe3+ and DCP with cell imaging application(Elsevier B.V., 2023-05-17T00:00:00) Kathuria, Vishal; Kiran; Rani, Payal; Mayank; Joshi, Gaurav; Kumar, Roshan; Sindhu, Jayant; Kumar, Parvin; Negi, Arvind; Kumar, SudhirTwo new turn-off fluorescent sensors (V3 and V4) presented in the article revealed the potential application for the precise detection of Fe3+ and diethylchlorophosphate (DCP). These sensors include oxazolonaphthoimidazo[1,2-a]pyridine scaffold integrated with anthracene and pyrene-based framework. This design has facilitated the twisted intramolecular charge transfer (TICT) and planarised intramolecular charge transfer (PLICT) mechanisms, which were confirmed using computational and photophysical studies. The V3 and V4 fluorescent probes were particularly sensitive and highly selective for detecting Fe3+ and DCP analytes. For Fe3+, V3 and V4 undergo turn-off mechanism with the detection limit of 14.1 and 4.5 nM, respectively. Intracellular detection of Fe3+ via confocal live cell imaging was also demonstrated, showing its application under intracellular conditions. Our experimental data revealed the promises of V3 and V4 for instantaneous, accurate and on-spot monitoring of Fe3+ and DCP, even in the presence of other interfering analytes. � 2023 Elsevier B.V.Item Discovery of potent inhibitors targeting Glutathione S-transferase of Wuchereria bancrofti: a step toward the development of effective anti-filariasis drugs(Institute for Ionics, 2023-02-16T00:00:00) Sureshan, Muthusamy; Prabhu, Dhamodharan; Rajamanikandan, Sundarraj; Saraboji, KadhirvelLymphatic filariasis (LF) is one of the major health problems for the human kind in developing countries including India. LF is caused by three major nematodes namely Wuchereria bancrofti, Brugia malayi, and Brugia timori. The recent statistics of World Health Organization (WHO) showed that 51 million people were affected and 863 million people from 47 countries around worldwide remain threatened by LF. Among them, 90% of the filarial infection was caused by the nematode W. bancrofti. Approved drugs were available for the treatment of LF but many of them developed drug resistance and no longer effective in all stages of the infection. In the current research work, we explored the Glutathione S-transferase (GST) of W. bancrofti, the key enzyme responsible for detoxification that catalyzes the conjugation of reduced GSH (glutathione) to xenobiotic compounds. Initially, we analyzed the stability of the WbGST through 200 ns MD simulation and further structure-based virtual screening approach was applied by targeting the substrate binding site to identify the potential leads from small molecule collection. The in silico ADMET profiles for the top-ranked hits were predicted and the predicted non-toxic lead molecules showed the highest docking score in the range of ?�12.72 kcal/mol to ?�11.97 kcal/mol. The cross docking of the identified hits with human GST revealed the potential binding specificity of the hits toward WbGST. Through WbGST�lead complex simulation, the lead molecules were observed to be stable and also intactly bound within the binding site of WbGST. Based on the computational results, the five predicted non-toxic molecules were selected for the in vitro assay. The molecules showed significant percentage of inhibition against the filarial worm Setaria digitata which is the commonly used model organism to evaluate the filarial activity. In addition, the molecules also showed better IC50 than the standard drug ivermectin. The identified lead molecules will lay a significant insight for the development of new drugs with higher specificity and lesser toxicity to control and treat filarial infections. Graphical abstract: [Figure not available: see fulltext.] � 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.Item Precisely designed oxazolonaphthoimidazo[1,2-a]pyridine-based sensor for the detection of Fe3+ and DCP with cell imaging application(Elsevier B.V., 2023-05-17T00:00:00) Kathuria, Vishal; Kiran; Rani, Payal; Mayank; Joshi, Gaurav; Kumar, Roshan; Sindhu, Jayant; Kumar, Parvin; Negi, Arvind; Kumar, SudhirTwo new turn-off fluorescent sensors (V3 and V4) presented in the article revealed the potential application for the precise detection of Fe3+ and diethylchlorophosphate (DCP). These sensors include oxazolonaphthoimidazo[1,2-a]pyridine scaffold integrated with anthracene and pyrene-based framework. This design has facilitated the twisted intramolecular charge transfer (TICT) and planarised intramolecular charge transfer (PLICT) mechanisms, which were confirmed using computational and photophysical studies. The V3 and V4 fluorescent probes were particularly sensitive and highly selective for detecting Fe3+ and DCP analytes. For Fe3+, V3 and V4 undergo turn-off mechanism with the detection limit of 14.1 and 4.5 nM, respectively. Intracellular detection of Fe3+ via confocal live cell imaging was also demonstrated, showing its application under intracellular conditions. Our experimental data revealed the promises of V3 and V4 for instantaneous, accurate and on-spot monitoring of Fe3+ and DCP, even in the presence of other interfering analytes. � 2023 Elsevier B.V.Item First principles study of electronic and thermoelectric performance of Li intercalated MoSe 2 nanotubes(American Institute of Physics Inc., 2017) Sharma, Munish; Kumar, Ashok; Pandey, Rabindra; Ahluwalia, P. K.We present a comparative study of pristine and Li intercalated MoSe 2 nanotube of armchair (6, 6) and zigzag (10, 0) chirality within the framework of density functional theory (DFT). Pristine nanotube is found to have band gap which vanishes upon Li intercalation. Additionally, Li intercalation results in reduction of room temperature ZT e for armchair MoSe 2 nanotube and enhancement in ZT e for intercalated zigzag MoSe 2 nanotube as compared to respective pristine nanotubes. Our results suggest that Li intercalation leads to a relatively high Seeback coefficient which may enhance the thermoelectric performance of zigzag MoSe 2 nanotube.Item Topological insulator behavior of WS 2 monolayer with square-octagon ring structure(American Institute of Physics Inc., 2016) Kumar, Ashok; Pandey, Ravindra; Ahluwalia, P. K.; Tankeshwar, K.We report electronic behavior of an allotrope of monolayer WS 2 with a square octagon ring structure, refereed to as (so-WS 2 ) within state-of-the-art density functional theory (DFT) calculations. The WS 2 monolayer shows semi-metallic characteristics with Dirac-cone like features around Cyrillic capital letter GHE. Unlike p-orbital's Dirac-cone in graphene, the Dirac-cone in the so-WS 2 monolayer originates from the d-electrons of the W atom in the lattice. Most interestingly, the spin-orbit interaction associated with d-electrons induce a finite band-gap that results into the metal-semiconductor transition and topological insulator-like behavior in the so-WS 2 monolayer. These characteristics suggest the so-WS 2 monolayer to be a promising candidate for the next-generation electronic and spintronics devices.