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This study presents a novel material for highly efficient adsorption of sulforaphane based on SBA-15. The SBA-15 nanoparticles were synthesized using natural silica by hydrothermal method and functionalized with thiol and amine groups by the post-synthesis grafting procedure. All adsorbents were characterized by various techniques including BET, LAXRD, FT-IR, FE-SEM, and CHNS. The batch adsorption experiments revealed that the adsorption efficiency of SBA-15 for sulforaphane can be mainly influenced by the introduction of functional groups and the best adsorption performance was observed for amine-functionalized SBA-15 (SBA-15-NH2) compared to pure SBA-15 and thiol-functionalized SBA-15 (SBA-15-SH) with the highest adsorption efficiency of about 97%. Preliminary adsorption studies of sulforaphane onto SBA-15-NH2 were performed in aqueous solutions with different pH values and various organic solvents. Also, the effects of adsorbent dosage, contact time, and initial sulforaphane concentration on sulforaphane adsorption using SBA-15-NH2 were studied. Langmuir and Redlich-Peterson isotherm models were the best-fitting models for the experimental data, followed by Temkin, Freundlich, and Dubinin-Radushkevich models. The adsorption process could be well described by the pseudo-first-order kinetic model based on kinetic parameters, correlation coefficient, and error functions. Meanwhile, the intra-particle diffusion model showed a multi-linear plot with three steps demonstrating slow diffusion into mesopores as a rate-limiting step.

A practical and an efficient Schiff base fluorescent chemosensor, salicylidene-4-aminoantipyrinyl-4-aminophenol (A2) has been synthesized through the condensation procedure of 1-phenyl-2,3-dimethyl-4-(N-2-hydroxybenzylidene)-3-pyrazoline-5-one and 4-aminophenol. Compound A2 has displayed a considerable fluorescence enhancement with high selectivity and sensitivity toward Al3+ ion and exhibited an emission band at 484 nm, which contained a low detection limit (LOD) of 1.06 × 10−7 M. In accordance to the experimental study, DFT, TDDFT calculations, and the enhancement of fluorescence intensity might be attributed to the inhibition of Photoinduced Electron Transfer (PET) along with the Excited-State Intramolecular Proton Transfer (ESIPT). As it has been specified by Job's plot and DFT calculations, the binding stoichiometries of A2 with Al3+ are 1:1, while the association constant (Ka) of Al3+ has been calculated and observed to be 2.67 × × 105 M−1. Furthermore, the binding behavior and sensing mechanism of A2 with Al3+ have been confirmed through the experiments of 1H NMR titration.

The highly contagious Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which is a newborn infectious member of the dangerous beta-coronaviruses (β-CoVs) following SARS and MERS‐CoVs, can be regarded as the most significant issue afflicting the whole world shortly after December 2019. Considering CoVs as RNA viruses with a single-stranded RNA genome (+ssRNA), the critical viral enzyme RNA dependent RNA polymerase (RdRp) is a promising therapeutic target for the potentially fatal infection COVID-19. Nicotinamide riboside (NR), which is a naturally occurring analogue of Niacin (vitamin B3), is expected to have therapeutic effects on COVID-19 due to its super close structural similarity to the proven RdRp inhibitors. Thus, at the first phase of the current molecular docking and dynamics simulation studies, we targeted SARS-CoV-2 RdRp. On the next phase, SARS-CoV RdRp, human Angiotensin-converting enzyme 2, Inosine-5’-monophosphate dehydrogenase, and the SARS-CoV-2 Structural Glycoproteins Spike, Nonstructural viral protein 3-Chymotrypsin-like protease, and Papain-like protease were targeted using the docking simulation to find other possible antiviral effects of NR serendipitously. In the current study, the resulted scores from molecular docking and dynamics simulations as the primary determinative factor as well as the observed reliable binding modes have demonstrated that Nicotinamide Riboside and its active metabolite NMN can target human ACE2 and IMPDH, along with the viral Spro, Mpro, PLpro, and on top of all, RdRp as a potential competitive inhibitor., Graphical Abstract Image, graphical abstract

A novel Schiff base fluorescent sensor N,N′-bis(salicylidene)-2,6-bis(4-aminophenyl)-4-phenylpyridine (P3) was synthesized through condensation of 2,6-bis(4-aminophenyl)-4-phenylpyridine and 2-hydroxybenzaldehyde. The obtained results from fluorescence analysis revealed that by excess of Cr3+ to P3, a remarkable increase was observed in the fluorescent intensity of the Schiff base at 663 nm with the ratio of CH3CN/H2O (95/5%), even though the other cations would likely have no impact on the fluorescence intensity. The cause of this trend might be ascribed to the formation of a 1:1 stoichiometric P3-Cr3+ complex, confirmed by Job's plot, which is resulted in preventing the photo-induced electron transfer (PET) process. From fluorescence titration, the association constant Ka was gained 2.28 × 105 M−1 and the limit of detection (LOD) was determined to be 1.3 × 10−7 M. Furthermore, the optimized structure together with the electronic spectra of the proposed complex was determined by DFT and TDDFT calculations.

In 2015, phagraphene was introduced as a novel nanostructure, opening a new avenue in carbonaceous nanomaterial research. Herein, we investigated the potential application of phagraphene as a drug delivery system for anti-cancer adrucil, based on the density functional theory calculations. Results indicate that adrucil drug very weakly interacts with the phagraphene with adsorption energy about −2.9 kcal/mol. This makes the phagraphene inappropriate for the drug delivery. To overcome this problem, the phagraphene is doped with different impurity atoms including B, Al, and Si. It was found that the reactivity of the studied systems is as follows: Al-doped > Si-doped > B-doped > pristine phagraphene. Although doping of phagraphene with B atom increases the reactivity, the electronic properties of the B-doped phagraphene considerably change at the presence of the drug which makes it unsuitable for drug delivery. Also, the Al-doped phagraphene suffers from a large desorption time because of a large negative adsorption energy (−41.8 kcal/mol). Among the all systems, we predicted that Si-doped phagraphene is more appropriate for adrucil delivery because of a moderate adsorption energy (−14.0 kcal/mol), a short recovery time (0.02 s), and electronically harmless adsorption property.

2-((9H-fluoren-2-ylimino) methyl)phenol (F3) was synthesized by condensation reaction of 9H-fluoren-2-amine and 2-hydroxybenzaldehyde in EtOH and characterized by its melting point, 1H-,13C NMR and molecular mass. F3 exhibits a high selectivity for detection of Cr3 + and Al3 + ions as a fluorescent chemosensor and showed a single emission band at 536 nm upon excitation at 333 nm according to fluorescence emission studies. The addition of Cr3 + and Al3 + make a significant increase in fluorescent intensity at 536 nm in CH3CN, while other metal ions have almost no influence on the fluorescence. The fluorescence enhancement was attributed to the inhibited C N isomerization and the obstructed excited state intra-molecular proton transfer (ESIPT) of compound F3. Job's plot and DFT calculations data showed that the binding stoichiometries of F3 with Cr3 + and Al3 + are 2:1. The association constants (Ka) for Cr3 + and Al3 + were calculated and found to be 8.33 × 104 M− 1 and 5.44 × 104 M− 1, respectively. The detection limits were also calculated for Cr3 + and Al3 + and found to be 2.5 × 10− 7 mol/L and 3.1 × 10− 7 mol/L, respectively.

Cathinone (CT) is a psychoactive drug which its abuse is linked to several deaths worldwide. Here, we investigated the electronic response of BC 2 N nanotubes to the CT drug, using density functional theory calculations. Our results indicate that the CT drug is adsorbed on the pristine tube from its –NH 2 group with ad adsorption energy about −14.6 kcal/mol with no electronic response. To overcome this problem, we doped the tube with Al or Si atom. Both of the Al and Si dopants increase the tube sensitivity and strengthen the interaction. Our calculations demonstrate that despite the high sensitivity of the Al-doped BC 2 N nanotube to the CT drug, it suffers from a very long recovery time which makes it unsuitable for application in CT sensors. But the calculated recovery time for the Si-doped BC 2 N nanotube is predicted to be about 0.27 s , which is short and desirable. Also, we showed that the Si-doped tube can be used in the humidity condition and at the presence of some gases including H 2 , O 2 , N 2 , and CO 2 . It was concluded that Si-doped BC 2 N nanotubes may be promising candidate for application in the CT sensors which benefit form a short recovery time, high sensitivity, and selectivity.

Cathinone is an organic stimulant which is classified as psychoactive drug and its abuse has been linked to many deaths worldwide. Here, we studied the electronic sensitivity of a BN cage, a zigzag (6, 0) BN nanotube, and a BN nanosheet toward cathinone using density functional theory calculations. The B3LYP-D functional predicts that the order of magnitude of electrical conductivity of BN nanostructures is as follows tube > sheet > cage. The cathinone drug prefers to be adsorbed on the BN nanostructures via its NH2 group rather than O-head with adsorption energy about −16.1, −14.0 and −5.0 kcal/mol for cage, tube, and sheet, respectively. Our results indicate that by increasing the p-character of the hybridization of the adsorbing B atom in the BN nanostructures, the interaction is strengthened. Based on the density of states analysis, it was demonstrated that the electrical conductivity of the BN nanostructures is decreased by the drug adsorption, indicating that they can be used in the cathinone sensors. The order of magnitude of the sensitivity is as follows: SCage > STube > SSheet. This trend corresponds to the decrease of the structural curvature in the BN nanostructures. Finally, a short recovery time of about 0.54 s, 0.02 s and 4.4 ns is predicted for cage, tube and sheet, respectively, at 298 K.

We investigated the interaction of benzoylethanamine (BEA) drug with the AlN nanostructures including nanotube, nanocage, and nanosheet using density functional theory calculations. We predicted that the BEA molecule tends to be mainly adsorbed from its N-head on the Al atom of the AlN nanostructures with adsorption energy of − 66.0, − 126.2, and − 147.1 kJ/mol for nanosheet, nanotube, and nanocage, respectively. This indicates that by increasing the structural curvature, the interaction is strengthened. Also, it seems that by decreasing the structural curvature of the AlN nanostructures from nanocage to the nanosheet, the kinetic stability is increased which leads to an increase in the gap. When a BEA molecule is adsorbed on the AlN nanostructures, their electrical conductivity is increased, demonstrating that they can yield an electronic signal at the presence of this molecule and can be employed in chemical sensors. The order of magnitude of the sensitivity is as follows: S Nanosheet > S Nanotube > S Nanocage . We concluded that among the AlN nanostructures, the AlN nanosheet may be promising candidate for detection of BEA drug which benefits from a short recovery time of 0.33 s.

Using density functional theory calculations, we investigated the stability, solubility, structural, electronic, and optical properties of C30X15Y15 (X = B, and Al; Y = N, and P) heterofullerenes. The C30B15N15 is found to be the most stable heterofullerene with standard formation enthalpy (ΔH°f) of 222.2 kcal/mol, followed by C30Al15N15 (ΔH°f = 891.6 kcal/mol). The relative stability of fullerenes are as follows: BN > C60 > AlN ∼ BP > AlP, indicating that the BN doping makes the C60 more stable. The XY doping process significantly increases and decreases the solubility of C60 fullerene in water and benzene solvents, respectively. The standard Gibbs free energy of solvation (ΔG°solv) of C60 in water is increased from −0.7 to −33.5 kcal/mol by AlN doping process. The dopant X atoms are mainly contributed in generation of occupied states but the Y ones largely create the virtual states. Compared to the pristine C60, the electrical conductivity of the XY doped fullerenes are higher, and the order is as follows: AlP > BP > BN ∼ AlN >> C60. This indicates that the Al atoms destabilize and P ones stabilize the HOMO and LUMO levels, respectively. The optical gap of these fullerenes is smaller than the HOMO-LUMO gap by about 0.44–0.55 eV.

N , N′ -bis(salicylidene)-2-(6-(2-aminophenyl)-4-phenylpyridin-2-yl) ( 3 ) was synthesized by condensation reaction of 2,6-bis(2-aminophenyl)-4-phenylpyridine and 2-hydroxybenzaldehyde in EtOH and characterized by its melting point, 1 H, 13 C NMR and molecular mass. The addition of Cr 3+ ion makes the significant increase of its fluorescent intensity at 537 nm in CH 3 CN/H 2 O (95/5%), however, other metal ions have almost no influence on the fluorescence. The reason for this phenomenon might be attributed to the formation of a 1:1 stoichiometric 3 -Cr 3+ complex which inhibits photo-induced electron transfer (PET) process. The 1:1 binding stoichiometry between 3 and Cr 3+ was established using Job’s plot, and the complex structure was proposed by DFT calculation. The association constant ( K a ) was determined to be 8.77 × 10 4 M −1 and the limit of detection (LOD) was calculated to be 2.2 × 10 −7 M.

Never agent identification and disposal is vital for both civilian and military defense resources. Herein, using density functional theory calculations, the reactivity and electronic sensitivity of pristine, Stone Wales (SW) defected, and Si-doped BN (Si-BN) nanosheets toward cyclosarin nerve agent were investigated. It was found that the interaction of cyclosarin with the pristine BN sheet is very weak and also that is not energetically favorable with SW defected one. Unlike the SW defect, replacing a B atom by Si atom significantly makes the cyclosarin adsorption energetically favorable. Calculations show that the carbonyl and etheric oxygen atoms of cyclosarin attack the Si atom of Si-BN with the adsorption energies of −73.5 and −136.9 kJ/mol, respectively. The cyclosarin nerve agent can be decomposed by the Si-BN sheet which is thermodynamically highly favorable. Upon this process, the HOMO and LUMO levels are significantly unstabilized and the HOMO-LUMO gap significantly changed by about 24.2%. The cyclosarin presence and its decomposition by Si-BN sheet can be recognized because of the electrical conductivity change of the sheet.

It has been recently indicated that the Li-ion batteries may be replaced by Na-ion batteries because of their low safety, high cost, and low-temperature performance, and lack of the Li mineral reserves. Here, using density functional theory calculations, we studied the potential application of B12N12 nanoclusters as anode in Na-ion batteries. Our calculations indicate that the adsorption energy of Na+ and Na are about -23.4 and -1.4kcal/mol, respectively, and the pristine BN cage to improve suffers from a low cell voltage (∼0.92V) as an anode in Na-ion batteries. We presented a strategy to increase the cell voltage and performance of Na-ion batteries. We showed that encapsulation of different halides (X=F-, Cl-, or Br-) into BN cage significantly increases the cell voltage. By increasing the atomic number of X, the Gibbs free energy change of cell becomes more negative and the cell voltage is increased up to 3.93V. The results are discussed based on the structural, energetic, frontier molecular orbital, charge transfer and electronic properties and compared with the performance of other nanostructured anodes.

This review article surveys literature methods for the carboxylative cyclization of N -propargylamines with CO 2 to provide 2-oxazolidinones. We have classified these reactions based on the type of catalysts.

Nanographenes are definite segments of graphene whose end atoms are saturated with hydrogens and their properties are different from those of the graphene because of size confinement. Herein, we investigated the structural properties, reactivity and electronic sensitivity of a newly synthesized borazine-like ring doped nanographene (BNG) to NO2 gas by means of density functional theory. We found that the central and peripheral rings of BNG are aromatic, while the middle ones are non-aromatic, revealing that this pattern follows the Clar’s sextet rule of aromaticity. Different thermodynamically stable NO2/BNG complexes are predicted, but most of them cannot be formed at room temperature because of the high transition barrier energies. The most favorable complex is that in which one oxygen atom of NO2 molecule is located above the center of B3N3 doped ring with adsorption energy of about −5.1 kcal/mol. It was found that the electronic properties of BNG are highly sensitive to the presence of NO2 molecules so that after the NO2 adsorption, the BNG is converted from a semiconductor to a semimetal compound. Thus, it was concluded that the BNG may be used in the NO2 sensor devices. Also, a short recovery time is predicted for the NO2 desorption process.

We studied the effect of Hartree-Fock (HF) exchange percentage of a density functional on the adsorption properties and electronic sensitivity of the B 12 N 12 nanocluster to CO molecule. It was found that by an increase in the %HF, the LUMO level is nearly constant while the HOMO level is strongly stabilized, expanding the HOMO-LUMO gap (E g ). Also, the volume of the all structures decreased and the sensitivity of the B 12 N 12 is slightly increased to CO molecule. For the pristine B 12 N 12 cluster, the B66 and B64 bonds are about 1.43 and 1.49 A at 10% HF, and 1.23 and 1.26 A at 100% HF, respectively. The HF exchange between 10–20% may predict an accurate E g for the B 12 N 12 system. We concluded that functionals with a large %HF such as M06-HF, and M06-2X may significantly overestimate the E g , and bond strength. We obtained a parabolic relationship between the %HF and the adsorption energy of CO molecule on the B 12 N 12 cluster. Also, an increase in the %HF predicts a larger charge transfer from the CO molecule to the cage.

Detection of illicit drugs is of increasing interest for police and drug communities because of their abuse. Using density functional calculations, we investigated the interaction of amphetamine (AA) drug with the pristine, B, Al, Ga (group IIIA), Si, and Ge (IIV group) doped C60 fullerenes. The AA cycloaddition from its phenyl ring to the [6–6] bonds of C60 is more favorable than that to the [5–6] bonds, in good agreement with experiment. When an AA molecule is adsorbed from its –NH2 group on the C60 fullerene, its work function is significantly decreased, showing a good sensitivity but the adsorption energy (−0.4 kcal/mol) is very small. Replacing a carbon atom of C60 by the impurity atoms, the interaction between the AA and the C60 is largely improved (adsorption energy ∼ −38.6 to −65.6 kcal/mol). Upon the adsorption of AA on the doped fullerenes, the Fermi level is largely shifted to higher energy, especially in the case of Si and Ge-doped fullerenes, and thus, the work function decreases by about 22.7 and 24.9%, respectively. The electron emission largely increases which can be converted to an electronic noise. However, the Si and Ge-C60 fullerenes are work function-type sensors for AA drug.

We investigated the reactivity and sensitivity of pristine, and Al-doped boron nitride (Al-BN) nanosheets to nerve agents including cyclosarin (GF) and tabun (GA) by means of density functional calculations. A weak interaction is predicted for both GF and GA with the pristine BN sheet with adsorption energies of − 12.0 and − 10.9 kcal/mol, respectively. Calculations show that the carbonyl oxygen atom of both GF and GA are the most nucleophile active site. The electronic sensitivity of the BN nanosheet is predicted to be negligible to these nerve agents. To overcome this problem, we have replaced a B atom of the sheet by an Al atom and investigated the adsorption process. It was found that the reactivity of the sheet in significantly increased to these agents after the Al-doping while the electronic sensitivity is improved only for GA gas. By adsorbing the GA on the Al-BN, its electrical conductivity is largely increased because of a decrease about 32.6% in the HOMO-LUMO energy gap. We have concluded that the Al-doping process helps the BN sheet to detect the GA gas and may be used in its sensor devices.

The electronic, optical, energetic, and structural properties of a HBC (hexa-peri-hexabenzocoronene) nanographene and its central benzene- and coronene-like BN substituted forms, and also full BN analogue were investigated using density functional theory. It was found that a larger number of carbon atoms cause a more negative cohesive energy and, thereby a greater structural stability. Our nucleus independent chemical shift analysis indicates that the aromaticity and Clar’s sextet rule determine the relative stability of these structures. The benzene-like or coronene-like doping makes the HBC more insulator or semiconductor. Electron-hole Frenkel type exciton binding energy was predicted and calculated to be nearly identical for all nanographenes in the range of 0.61–0.69 eV. The coronene-like BN-doped HBC (BN2-HBN) shows higher conductivity due to very narrow optical and HOMO-LUMO energy gap. Partial density of states analysis indicates that the BN2-HBC electronically can be assumed a full BN whose peripheral atoms are replaced by carbon atoms. These carbon atoms are responsible for new states which are appeared within the gap.

We report an efficient and convenient method for preparing nitro-3-carboxamide coumarin derivatives, proposed as novel fluorescent chemosensor, through microwave irradiation. This compound can be used as fluorescent probe for Cu(2+) with selectivity over other metal ions in aqueous solution. The fluorescence of 6-nitro-N-[2-(dimethylamino)ethyl]-2-oxo-2H-chromene-3-carboxamide(3) is the highest in the presence of Cu(2+), with stronger excitation at λ=320nm than for the other cations tested.

The electronic sensitivity and reactivity of pristine, and BN doped graphyne (BNG) are scrutinized toward mustard gas using DFT calculations. The mustard gas weakly adsorbs via its Cl atom on the graphyne with adsorption energy about -3.1 kcal/mol and has no effect on its electrical conductivity. Replacing –C≡C– linkages with isoelectronic –B N– linkages increases the HOMO-LUMO gap (Eg) and decreases the work function and reactivity of graphyne. By mustard adsorption, the Eg of BNG decreases from 2.24 to 1.12 eV, increasing the electrical conductivity. Also, the BNG work function is considerably affected, changing the field emission electron current. Finally, a short recovery time about 0.03 s at room temperature is predicted for the mustard desorption from the surface of BNG. We also showed that the electrical conductivity change relates to the mustard concentration. The results indicate that the BNG may be a promising sensor for mustard gas.

Calculations were performed for investigation of the properties of the electronic structure of Carbon- Doped Boron Phosphide Nanotube (CDBPNT). Pristine and three models of C-doped structures of (6,0) zigzag BPNT were studied at density functional theory (DFT) in combination with 6-311G* basis set using Gaussian package of program. The calculated parameters reveal that various 11 B and 31 P nuclei are divided into some layers with equivalent electrostatic properties. The electronic structure properties are highly influenced by replacement of 11 B and 31 P atoms by 12 C atoms in pristine model. Furthermore, the HOMO−LUMO gap energy for suggested doped models (I), (II) and (III) were lower than pure BPNT pristine systems. The dipole moment values of models (II) and (III) were decreased to 1.788 and 1.789, respectively while the dipole moments of model (I) were enhanced to 4.373, in compare to pure pristine one (2.586). The magnitude of changes in Chemical Shielding (CS) tensor parameters revealed that the electron density at the site of 31 P was higher than that at the site of 11 B due to carbon doping.

A novel chemiluminescence (CL) method using water-soluble Mn-doped ZnS quantum dots (QDs) as CL emitter is proposed for the chemiluminometric determination of folic acid in pharmaceutical formulation. Water-soluble Mn-doped ZnS QDs were synthesized by using L-cysteine as stabilizer in aqueous solutions. The nanoparticles were structurally and optically characterized by X-ray powder diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectroscopy and photoluminescence (PL) emission spectroscopy. The CL of ZnS QDs induced by directly chemical oxidation and its ionic liquid-sensitized effect in aqueous solution were then investigated. It was found that oxidants, especially hydrogen peroxide, could directly oxidize ZnS QDs to produce weak CL emission in basic conditions. In the presence of 1,3-dipropylimidazolium bromide/copper a drastic light emission enhancement is observed, related to a strong interaction between Cu(2+) and the imidazolium ring. Therefore, a new CL analysis system was developed for the determination of folic acid. Under the optimum conditions, there is a good linear relationship between the relative CL intensity and the concentration of folic acid in the range of 1×10(-9)-1×10(-)(6) M of folic acid with a correlation coefficient (R(2)) of 0.9991. The limit of detection of this system was found to be 1×10(-)(10) M. This method is not only simple, sensitive and low cost, but also reliable for practical applications.

A novel chemiluminescence (CL) method using water-soluble Mn-doped ZnS quantum dots (QDs) as sensitizers is proposed for the chemiluminometric determination of atropine in pharmaceutical formulation. Water-soluble Mn-doped ZnS QDs were synthesized by using l -cysteine as stabilizer in aqueous solutions. The nanoparticles were structurally and optically characterized by X-ray powder diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), UV–vis absorption spectroscopy and photoluminescence (PL) emission spectroscopy. It was found that ZnS quantum dots acted as enhancers of the weak CL emission produced upon oxidation of sulfite by Ce(IV) in acidic medium. Trace amounts of atropine improved the sensitize effect of ZnS quantum dots yielding a significant chemiluminescence enhancement of the Ce(IV)–SO 3 2− –ZnS QD system. Therefore, a new CL analysis system was developed for the determination of atropine. Under the optimum conditions, there is a good linear relationship between the relative chemiluminescence intensity and the concentration of atropine in the range of 1×10 −9 –1×10 −6 M of atropine with a correlation coefficient ( R 2 ) of 0.9992. The limit of detection of this system was found to be 2.54×10 −10 M. This method is not only simple, sensitive and low cost, but also reliable for practical applications.