First-principle study of Cu-, Ag-, and Au-decorated Si-doped carbon quantum dots (Si@CQD) for CO2 gas sensing efficacies.

CONTEXT: Nanosensor materials for the trapping and sensing of CO2 gas in the ecosystem were investigated herein to elucidate the adsorption, sensibility, selectivity, conductivity, and reactivity of silicon-doped carbon quantum dot (Si@CQD) decorated with Ag, Au, and Cu metals. The gas was studied in two configurations on its O and C sites. When the metal-decorated Si@CQD interacted with the CO2 gas on the C adsorption site of the gas, there was a decrease in all the interactions with the lowest energy gap of 1.084 eV observed in CO2_C_Cu_Si@CQD followed by CO2_C_Au_Si@CQD which recorded a slightly higher energy gap of 1.094 eV, while CO2_C_Ag_Si@CQD had an energy gap of 2.109 eV. On the O adsorption sites, a decrease was observed in CO2_O_Au_Si@CQD which had the least energy gap of 1.140 eV, whereas there was a significant increase after adsorption in CO2_O_Ag_Si@CQD and CO2_O_Cu_Si@CQD with calculated ∆E values of 2.942 eV and 3.015 eV respectively. The adsorption energy alongside the basis set supposition error (BSSE) estimation reveals that CO2_C_Au_Si@CQD, CO2_C_Ag_Si@CQD, and CO2_C_Cu_Si@CQD were weakly adsorbed, while chemisorption was present in the CO2_O_Ag_Si@CQD, CO2_O_Cu_Si@CQD, and CO2_O_Au_Si@CQD interactions. Indeed, the adsorption of CO2 on the different metal-decorated quantum dots affects the Fermi level (Ef) and the work function (Φ) of each of the decorated carbon quantum dots owed to their low Ef values and high ∆Φ% which shows that they can be a prospective work function-based sensor material. METHODS: Electronic structure theory method based on first-principle density functional theory (DFT) computation at the B3LYP-GD3(BJ)/Def2-SVP level of theory was utilized through the use of the Gaussian 16 and GaussView 6.0.16 software packages. Post-processing computational code such as multi-wavefunction was employed for result analysis and visualization.

Molecular simulation of Cu, Ag, and Au-decorated Si-doped graphene quantum dots (Si@QD) nanostructured as sensors for SO2 trapping.

In view of the numerous environmental hazards and health challenges linked to sulfur (iv) oxide (SO2), an indirect greenhouse gas, and the resultant need to develop efficient gas nanosensor devices, this research had as its principal focus on the theoretical evaluation of the gas sensing potential of metals: Ag, Au and Cu functionalized silicon-doped quantum dots (Si@QD) for the detection and adsorption of SO2 gas investigated using the first-principles density functional theory (DFT) computation at the B3LYP-D3(BJ)/def2-SVP level of theory. Eight (8) possible adsorption modes: SO2_O_Si@QD, SO2_O_Ag_Si@QD, SO2_O_Au_Si@QD, SO2_O_Cu_Si@QD, SO2_S_Si@QD, SO2_S_Ag_Si@QD, SO2_S_Au_Si@QD, and SO2_S_Cu_Si@QD were considered based on SO2 interactions with the studied materials at the -S and -O sites of the SO2 molecule. The counterpoise correction (BSSE) showed that five of the eight interactions had favorable Ead + BSSE values ranging from -0.31 to -1.98 eV. All the eight interactions were observed to be thermodynamically favorable with ΔG and ΔH ranging from -129.01 to -200.24 kcal/mol and -158.26 to -229.73 kcal/mol respectively. Results from the topology analysis reveal that van der Waals forces occurred the greatest at the gas-sensor interphase while SO2_S_ Cu_Si@QD is predicted to have the highest sensing potency based on the conductivity and recovery time estimations. These results confirm the potential efficient feasibility of real-world device application of the metals (Ag, Au, Cu) functionalized Si-doped QDs.

Therapeutic Potential of B12N12-X (X = Au, Os, and Pt) Nanostructured as Effective Fluorouracil (5Fu) Drug Delivery Materials.

In view of the research-substantiated comparative efficiency of nontoxic and bioavailable nanomaterials synergic with human systems for drug delivery, this work was aimed at studying the comparative efficiency of transition metal (Au, Os, and Pt)-decorated B12N12 nanocages in the adsorption of fluorouracil (5Fu), an antimetabolite-classed anticarcinogen administered for cancers of the breast, colon, rectum, and cervix. Three different metal-decorated nanocages interacted with 5Fu drug at the oxygen (O) and fluorine (F) sites, resulting in six adsorbent-adsorbate systems whose reactivity and sensitivity were investigated using density functional theory computation at the B3LYP/def2TZVP level of theory with special emphasis on the structural geometry, electronic, and topology analysis as well as the thermodynamic properties of the systems. While the electronic studies predicted Os@F as having the lowest and most favorable Egp and Ead of 1.3306 eV and -11.9 kcal/mol, respectively, the thermodynamic evaluation showed Pt@F to have the most favorable thermal energy (E), heat capacity (Cp), and entropy (ΔS) values as well as negative ΔH and ΔG while the adsorption studies showed that the greatest degree of chemisorption with Ead magnitude of -204.5023 kcal/mol was observed in energies ranging from -12.0 to 138.4 kcal/mol with Os@F and Au@F at the lower and upper borders. The quantum theory of atoms in molecules results show that the six systems had noncovalent interactions as well as a certain degree of partial covalency but none showed covalent interaction while the noncovalent interaction analysis corroborated this by showing that the six systems had favorable interactions, though of varying degrees, with very little trace of steric hindrance or electrostatic interactions. Overall, the study showed that notwithstanding the good performance of the six adsorbent systems considered, the Pt@F and Os@F showed the most favorable potential for the delivery of 5Fu.

Anti-inflammatory biomolecular activity of chlorinated-phenyldiazenyl-naphthalene-2-sulfonic acid derivatives: perception from DFT, molecular docking, and molecular dynamic simulation.

In this study, two novel derivatives of naphthalene-2-sulfonic acid: 6-(((1S,5R)-3,5-dichloro-2,4,6-triazabicyclo [z3.1.0]hex-3-en-1-yl)amino)-5-((E)-phenyldiazenyl)naphthalene-2-sulfonic acid (DTPS1) and (E)-6-((4,6-dichloro-1,3,5-triazine2-yl)amino)-4-hydroxy-3-(phenyldiazenyl)naphthalene-2-sulfonic acid (DTPS2) have been synthesized and characterized using FT-IR, UV-vis, and NMR spectroscopic techniques. Applying density functional theory (DFT) at the B3LYP, APFD, PBEPBE, HCTH, TPSSTPSS, and ωB97XD/aug-cc-pVDZ level of theories for the electronic structural properties. In-vitro analysis, molecular docking, molecular dynamic (MD) simulation of the compounds was conducted to investigate the anti-inflammatory potential using COXs enzymes. Docking indicates binding affinity of -9.57, -9.60, -6.77 and -7.37 kcal/mol for DTPS1, DTPS2, Ibuprofen and Diclofenac which agrees with in-vitro assay. Results of MD simulation, indicates sulphonic group in DTPS1 has > 30% interaction with the hydroxyl and oxygen atoms in amino acid residues, but > 35% interaction with the DTPS2. It can be said that the DTPS1 and DTPS2 can induce inhibitory effect on COXs to halt biosynthesis of prostaglandins (PGs), a chief mediator of inflammation and pain in mammals.Communicated by Ramaswamy H. Sarma.