Basic Fuchsin Dye as the First Fluorophore for Optical Sensing of Morpholine in Fruits Crust and Urine Samples.

In this work, basic fuchsin (BF) dyestuff was presented as the first optical sensor used for the spectrofluorimetric assessment of morpholine (MOR) where BF exhibits morpholine-sensing behavior. The developed fluorimetric avenue is sensitive, facile, selective, and validated for assaying the sensitizing influence of MOR on the BF fluorescence in an aprotic dioxane solvent. Parameters like solvents, BF concentration, order, and time of addition that influence the fluorescence intensity of the probing system were addressed. Optimizing the analytical methodology revealed a linear fluorescence sensitization within the addition of MOR in the two concentration ranges of 5 × 10-9 to 1.0 × 10-7 mol L-1 and 2.0 × 10-7 to 3 × 10-6 mol L-1. The limit of detection (LOD) and limit of quantification (LOQ) were estimated to be 2.0 × 10-9 mol L-1 (0.17 ng mL-1) and 6.66 × 10-9 mol L-1 (0.567 ng mL-1), respectively. High levels of accuracy and precision are achieved when assaying spiked MOR either in pure solutions or samples of fruit peel extract and human urine. Moreover, the green character and practicality/applicability of the method were evaluated by AGREE and BAGI metric tools. These merit outcomes provide insights into the development of fluorescent sensors for MOR detection using fluorescent dyes and meet the Food and Drug Administration's requirements for morpholine detection in real-life applications.

A DFT study for improving the photovoltaic performance of organic solar cells by designing symmetric non-fullerene acceptors by quantum chemical modification on pre-existed LC81 molecule.

Minimizing the energy loss and improving the open circuit voltage of organic solar cells is still a primary concern for scientists working in this field. With the aim to enhance the photovoltaic performance of organic solar cells by minimizing energy loss and improving open circuit voltage, seven new acceptor molecules (LC1-LC7) are presented in this work. These molecules are designed by modifying the terminal acceptors of pre-existed "LC81" molecule based on an indacinodithiophene (IDT) fused core. The end-group modification approach is very fruitful in ameliorating the efficacy and optoelectric behavior of OSCs. The newly developed molecules presented remarkable improvements in performance-related parameters and optoelectronic properties. Among all designed molecules, LC7 exhibited the highest absorption maxima (λmax = 869 nm) with the lowest band-gap (1.79 eV), lowest excitation energy (Ex = 1.42 eV), lowest binding energy, and highest excited state lifetime (0.41 ns). The newly designed molecules LC2, LC3, and LC4 exhibited remarkably improved Voc that was 1.84 eV, 1.82 eV, and 1.79 eV accordingly, compared to the LC81 molecule with Voc of 1.74 eV LC2 molecule showed significant improvement in fill factor compared to the previously presented LC81 molecule. LC2, LC6, and LC7 showed a remarkable reduction in energy loss by showing Eloss values of 0.26 eV, 0.18 eV, and 0.25 eV than LC81 molecule (0.37 eV). These findings validate the supremacy of these developed molecules (especially LC2) as potential components of future OSCs.

Simultaneous green TLC determination of nirmatrelvir and ritonavir in the pharmaceutical dosage form and spiked human plasma.

Quantitative analysis of pharmaceutical compounds up to Nano gram levels is highly recommended to introduce feasible and sensitive tool for determination of the compounds in the pharmaceutical and biological samples. Nirmatrelvir plus ritonavir was recently approved in the US, the UK and Europe as a new co-packaged dosage form for the treatment of COVID-19. The objective of this work was to develop a more sensitive TLC method based on using ß-cyclodextrin as a chiral selector additive in the mobile phase for simultaneous determination of nirmatrelvir and ritonavir in pure form, pharmaceutical formulation and spiked human plasma. The analysis procedures were developed using TLC aluminum silica gel plates and methanol-water- 2% urea solution of ß-cyclodextrin (40:10:.5, by volume) as a mobile phase with UV detection at 215 nm. The developed method was successfully applied over a linearity range of 10-50 ng/band for both nirmatrelvir and ritonavir. The method was validated for limits of detection and quantitation, accuracy, precision, specificity, system suitability, and robustness. Furthermore, the eco-friendliness of the proposed method was assessed using the analytical eco-scale and the green analytical procedure index. The described method exhibited compliance with green analytical chemistry principles based on common green metric values.

LC-MS/MS approach for simultaneous assessment of hyoscine N-butyl bromide and ketoprofen in biological fluids and pharmaceuticals.

The mixture of hyoscine N-butyl bromide (HBB) and ketoprofen (KTP) is commonly used for the handling of abdominal spasms and pain relief. There are two challenges that restrict the simultaneous assessment of HBB and KTP in biological fluids and pharmaceuticals. The first issue is the difficulty of elution of HBB and the second one is the presence of KTP as a racemic mixture in all pharmaceutical formulations, which obscures its appearance as a single peak. An ultrasensitive and highly efficient liquid chromatography-mass/mass spectrometric (LC-MS/MS) method is designed and validated for the first concurrent assessment of HBB and KTP in spiked human serum and urine, and pharmaceutical formulations. The estimated linearity ranges for HBB and KTP were respectively, 0.5-500 and 0.05-500 ng/ml, with excellent correlation coefficients. Validation results showed that the value of relative standard deviations were <2% for HBB and KTP. The mean extraction recoveries for HBB and KTP were, respectively, 91.04 and 97.83% in Spasmofen® ampoules; 95.89 and 97.00% in spiked serum; and 97.31 and 95.63% in spiked urine. The presented innovative chromatographic approach was utilized for the measurement of trace amounts of coexisting pharmaceuticals in pharmacokinetics studies and routine therapeutic medication monitoring.

Adsorption of Molnupiravir anti-COVID-19 drug over B12N12 and Al12N12 nanocarriers: a DFT study.

The potentiality of B12N12 and Al12N12 nanocarriers to adsorb Molnupiravir anti-COVID-19 drug, for the first time, was herein elucidated using a series of quantum mechanical calculations. Density function theory (DFT) was systematically utilized. Interaction (Eint) and adsorption (Eads) energies showed higher negative values for Molnupiravir···Al12N12 complexes compared with Molnupiravir···B12N12 analogs. Symmetry-adapted perturbation theory (SAPT) results proclaimed that the adsorption process was predominated by electrostatic forces. Notably, the alterations in the distributions of the molecular orbitals ensured that the B12N12 and Al12N12 nanocarriers were efficient candidates for delivering the Molnupiravir drug. From the thermodynamic perspective, the adsorption process of Molnupiravir drug over B12N12 and Al12N12 nanocarriers had spontaneous and exothermic nature. The ESP, QTAIM, NCI, and DOS observations exposed the tendency of BN and Al12N12 to adsorb the Molnupiravir drug. Overall, these findings proposed that the B12N12 and Al12N12 nanocarriers are efficient aspirants for the development of the Molnupiravir anti-COVID-19 drug delivery process.Communicated by Ramaswamy H. Sarma.

Effects of Lewis Basicity and Acidity on σ-Hole Interactions in Carbon-Bearing Complexes: A Comparative Ab Initio Study.

The effects of Lewis basicity and acidity on σ-hole interactions were investigated using two sets of carbon-containing complexes. In Set I, the effect of Lewis basicity was studied by substituting the X3/X atom(s) of the NC-C6H2-X3 and NCX Lewis bases (LB) with F, Cl, Br, or I. In Set II, the W-C-F3 and F-C-X3 (where X and W = F, Cl, Br, and I) molecules were utilized as Lewis acid (LA) centers. Concerning the Lewis basicity effect, higher negative interaction energies (Eint) were observed for the F-C-F3∙∙∙NC-C6H2-X3 complexes compared with the F-C-F3∙∙∙NCX analogs. Moreover, significant Eint was recorded for Set I complexes, along with decreasing the electron-withdrawing power of the X3/X atom(s). Among Set I complexes, the highest negative Eint was ascribed to the F-C-F3∙∙∙NC-C6H2-I3 complex with a value of -1.23 kcal/mol. For Set II complexes, Eint values of F-C-X3 bearing complexes were noted within the -1.05 to -2.08 kcal/mol scope, while they ranged from -0.82 to -1.20 kcal/mol for the W-C-F3 analogs. However, Vs,max quantities exhibited higher values in the case of W-C-F3 molecules compared with F-C-X3; preferable negative Eint were ascribed to the F-C-X3 bearing complexes. These findings were delineated as a consequence of the promoted contributions of the X3 substituents. Dispersion forces (Edisp) were identified as the dominant forces for these interactions. The obtained results provide a foundation for fields such as crystal engineering and supramolecular chemistry studies that focus on understanding the characteristics of carbon-bearing complexes.

Adsorption of Chlormethine Anti-Cancer Drug on Pure and Aluminum-Doped Boron Nitride Nanocarriers: A Comparative DFT Study.

The efficacy of pure and aluminum (Al)-doped boron nitride nanocarriers (B12N12 and AlB11N12) in adsorbing Chlormethine (CM), an anti-cancer drug, was comparatively dissected by means of the density functional theory method. The CM∙∙∙B12N12 and ∙∙∙AlB11N12 complexes were studied within two configurations, A and B, in which the adsorption process occurred via N∙∙∙ and Cl∙∙∙B/Al interactions, respectively. The electrostatic potential affirmations confirmed the opulent ability of the studied nanocarriers to engage in delivering CM via two prominent electrophilic sites (B and Al). Furthermore, the adsorption process within the CM∙∙∙AlB11N12 complexes was noticed to be more favorable compared to that within the CM∙∙∙B12N12 analog and showed interaction and adsorption energy values up to -59.68 and -52.40 kcal/mol, respectively, for configuration A. Symmetry-adapted perturbation theory results indicated that electrostatic forces were dominant in the adsorption process. Notably, the adsorption of CM over B12N12 and AlB11N12 nanocarriers exhibited predominant changes in their electronic properties. An elemental alteration was also revealed for the softness and hardness of B12N12 and AlB11N12 nanocarriers before and following the CM adsorption. Spontaneity and exothermic nature were obviously observed for the studied complexes and confirmed by the negative values of thermodynamic parameters. In line with energetic manifestation, Gibbs free energy and enthalpy change were drastically increased by the Al doping process, with values raised to -37.15 and -50.14 kcal/mol, respectively, for configuration A of the CM∙∙∙AlB11N12 complex. Conspicuous enhancement was noticed for the adsorption process in the water phase more than that in the gas phase and confirmed by the negative values of the solvation energy up to -53.50 kcal/mol for configuration A of the CM∙∙∙AlB11N12 complex. The obtained outcomes would be the linchpin for the future utilization of boron nitride as a nanocarrier.

Flow-Injection Chemiluminescence Method for Sensitive Determination of Ascorbic Acid in Fruit Juices and Pharmaceutical Samples Using a Luminol-Cetyltrimethylammonium Chloride Reversed Micelle System.

A highly sensitive flow-injection (FI) method was developed for the determination of ascorbic acid using chemiluminescence (CL) based detection. This method involved the following processes: (1) reduction of tetrachloroaurate(III) in hydrochloric acid with ascorbic acid; (2) on-line extraction of the residual Au(III) with rhodamine B from the aqueous hydrochloric acid solution into toluene, followed by the separation of the Au(III)-containing organic phase from the aqueous phase through a microporous Teflon membrane in the flow system; and (3) the measurement of CL produced in a flow cell upon mixing of the extract stream of Au(III) in toluene with luminol in the reversed micellar medium of cetyltrimethylammonium chloride-water in 1-hexanol-cyclohexane, which was injected into a CL reagent stream. In this procedure, a reduction in the CL intensity occurred due to the addition of ascorbic acid to the Au(III) solution. The CL signal of Au(III) decreased with increasing concentration of ascorbic acid in the aqueous sample solution. The proposed procedure allowed the indirect quantitative determination of ascorbic acid in the range of 1.0 × 10-12 to 1.0 × 10-7 M with a correlation coefficient of 0.987 and relative standard deviation of 2.1% (n = 6) at 1.0 × 10-9 M. The proposed FI-CL methodology was successfully applied for quantitative determination of ascorbic acid in fruit juices and pharmaceutical samples.

A Flow Method for Chemiluminescence Determination of Antimony(III) and Antimony(V) Using a Rhodamine B-Cetyltrimethylammonium Chloride Reversed Micelle System Following On-Line Extraction.

A rapid and sensitive flow method, based on the combination of on-line solvent extraction with reversed micellar mediated chemiluminescence (CL) detection using rhodamine B (RB), was developed for the determination of antimony(III) and antimony(V) in aqueous samples. The on-line extraction procedure involved ion-pair formation of the antimony(V) chloro-complex anion with the protonated RBH(+) ion and its extraction from an aqueous hydrochloric acid solution into toluene, followed by phase separation using a microporous membrane. When in a flow cell of a detector, the ion-pair in the extract driven was mixed with the reversed micellar solution of cetyltrimethylammonium chloride in 1-hexanol-cyclohexane/water (0.60 mol dm(-3) H2SO4) containing cerium(IV), its uptake by the reversed micelles and the subsequent CL oxidation of RB with Ce(IV) occurred easily, then the produced CL signal was measured. Using the proposed flow method under the optimized experimental conditions, a detection limit (DL) of 0.35 µmol dm(-3) and a linear calibration graph with a dynamic range from DL to 16 µmol dm(-3) were obtained for Sb(V) with a precision of 1.4% relative standard deviation (n = 5) at the Sb(V) concentration of 8.2 µmol dm(-3). The present method was successfully applied to the determination of Sb(V) in water samples and to the differential determination of Sb(III) and Sb(V) in copper electrolyte industrial samples, where total antimony Sb(III) + Sb(V) was determined after oxidation of Sb(III) to Sb(V) with Ce(IV) and Sb(III) was calculated by difference, for which the DL was almost the same as that for Sb(V).

A flow method based on solvent extraction coupled on-line to a reversed micellar mediated chemiluminescence detection for selective determination of gold(III) and gallium(III) in water and industrial samples.

A rapid and sensitive flow method, based on the combination of on-line solvent extraction with reversed micellar mediated chemiluminescence (CL) detection using rhodamine B (RB), was investigated for the selective determination of Au(III) and Ga(III) in aqueous solutions. 2.0 M HCl was the optimum for extracting Au(III) while a 5.0M HCl solution containing 2.5M LiCl was selected as an optimum acidic medium for extraction of Ga(III). The Au(III) and Ga(III) chloro-complex anions were extracted from the above aqueous acidic solutions into toluene as their ion-pair complexes with the protonated RBH(+) ion followed by membrane phase separation in a flow system. In a flow cell of a detector, the extract was mixed with the reversed micellar solution of cetyltrimethylammonium chloride (CTAC) in 1-hexanol-cyclohexane/water (1.0M HCl) containing 0.10 M cerium(IV) and 0.05 M lithium sulfate. Then uptake of the ion-pair by the CTAC reversed micelles and the subsequent CL oxidation of RB with Ce(IV) occurred easily and the CL signals produced were recorded. Using a flow injection system, a detection limit (DL) of 0.4 µM Au(III) and 0.6 µM Ga(III), and linear calibration graphs with dynamic ranges from the respective DLs to 10 µM for Au(III) and Ga(III) were obtained under the optimized experimental conditions. The relative standard deviations (n=6) obtained at 2.0 µM Au(III) and 4.0 µM Ga(III) were 3.0% and 2.4%, respectively. The presented CL methodology has been applied for the determination of Au(III) and Ga(III) in water and industrial samples with satisfactory results.

Flow chemiluminescence determination of antimony(III,V) using a rhodamine B-cetyltrimethylammonium chloride reversed micelle system following liquid-liquid extraction.

A flow chemiluminescence (CL) method combined with a liquid-liquid extraction technique is proposed for the indirect determination of antimony in aqueous samples using rhodamine B (RB). In the liquid-liquid extraction process, the antimony(V) chloro-complex anion, [SbCl(6)](-), was extracted from an aqueous acidic solution into toluene via ion-pair formation with the protonated RBH(+) ion. Upon mixing the extract with a reversed micellar reagent solution of cetyltrimethylammonium chloride (CTAC) in 1-hexanol-cyclohexane/water (0.60 mol dm(-3) H(2)SO(4)) containing cerium(IV), uptake of the ion-pair by CTAC reversed micelles occurred easily, followed by an oxidation reaction of RB with Ce(IV) in the CL process. The CL signal produced was then measured. Using a flow injection system, the detection limits (DL) of 0.25 µmol dm(-3) Sb(III) and 0.20 µmol dm(-3) Sb(V), and linear calibration graphs with dynamic ranges from the respective DLs to 16 µmol dm(-3) for Sb(III) and Sb(V) were obtained under optimized experimental conditions. The proposed method was successfully applied to a mixture of Sb(III) and Sb(V), where total antimony, Sb(III) + Sb(V), was measured using ceric sulfate as an oxidant to oxidize Sb(III) to Sb(V) prior to extraction, Sb(V) was determined directly without the use of an oxidant, and Sb(III) was calculated by difference.

Chemiluminescence from an oxidation reaction of rhodamine B with cerium(IV) in a reversed micellar medium of cetyltrimethylammonium chloride in 1-hexanol-cyclohexane/water.

The chemiluminescence (CL) emission, observed when rhodamine B (RB) in 1-hexanol-cyclohexane was mixed with cerium(IV) sulfate in sulfuric acid dispersed in a reversed micellar medium of cetyltrimethylammonium chloride (CTAC) in 1-hexanol-cyclohexane/water, was investigated using a flow-injection system. The CL emission from the oxidation reaction of RB with Ce(IV) was found to be stronger in the CTAC reversed micellar solution compared with an aqueous solution. Bearing on the enhancement effect of the CTAC reverse micelles on the RB-Ce(IV) CL, several studies including stopped-flow, fluorescence and electron spin resonance (ESR) spectrometries were performed. Rapid spectral changes of an intermediate in the RB-Ce(IV) reaction in the aqueous and reversed micellar solutions were successfully observed using a stopped-flow method. The effect of the experimental variables, i.e., oxidant concentration, sulfuric acid concentration, the mole fraction of 1-hexanol, water-to-surfactant molar concentration ratio, flow rate, upon the CL intensity was evaluated. Under the experimental conditions optimized for a flow-injection determination of RB based on the new reversed micellar-mediated CL reaction with Ce(IV), a detection limit of 0.08 µmol dm(-3) RB was achieved, and a linear calibration graph was obtained with a dynamic range from 0.5 to 20 µmol dm(-3). The relative standard deviation (n = 6) obtained at an RB concentration of 3 µmol dm(-3) was 3%.

Acid-base behavior of rhodamine B in a reversed micellar medium of cetyltrimethylammonium chloride in 1-hexanol-cyclohexane/water.

The acid-base behavior of rhodamine B (RB) in reversed micellar solutions of cetyltrimethylammonium chloride (CTAC) in 1-hexanol-cyclohexane/water was investigated through absorption and fluorescence measurements under varying the hydrogen-ion concentration in a water pool, the mole fraction of 1-hexanol in a bulk solvent and the water to surfactant molar concentration ratio. RB exhibited equilibria between the cationic, zwitterion and lactone forms of the dye as a cause of the spectral changes, indicating a change in the RB distribution among the reversed micellar water pool, interface and bulk solvent. Furthermore, RB was used as a probe to develop a method for determining the critical micelle concentration (CMC) in CTAC solutions. Abrupt variations in the intensities and wavelengths of the absorption and emission maxima of RB were observed at the CMC. The standard free energy of micellization was also evaluated from the CMC data.