Impact of Mo+2 addition and thermal annealing on the surface morphology, electrical transport properties and Mott's parameters of WO3 films for potential photonic devices.

This work investigates the compositional dependence and thermal annealing of the morphological properties, electrical conductivity mechanisms and Mott's parameters of sprayed MoxW1-xO3 (x = 0, 0.05, 0.10 and 0,20) thin films. The prepared thin films were examined using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX) and Fourier transform infrared spectroscopy (FTIR) techniques. In addition, the two-point probe method was used to calculate the electrical properties of MoxW1-xO3 thin films. The FTIR results revealed that; the tungsten hydroxyl bond (W-OH) and the surface hydroxyl group vibrated within the ranges of 1558.62-1645.56 cm-1 and, 3296.76 and 3424.34 cm-1, respectively. Furthermore, a prominent band in the spectrum spanning from 850 to 650 cm-1 represents the W-O-W bridge mode. The FE-SEM investigations found that the molybdenum (Mo) dopant caused significant changes in the surface morphology of the films. The EDX results showed that the percentages of the isotropic elements MoxW1-xO3 agreed well with those obtained by atomic weight. Studies of the conduction mechanism indicate that the transition temperature was approximately 393K. Corresponding to Mott's model, the conduction mechanism below this temperature was across the variable hopping conduction band near the Fermi level. The mechanism exhibited a cycle of localised states through activated thermionic emission above 393K. Mott parameters were also estimated in addition to barrier potential energies, trapping state energies, local state densities, and other variables. The results revealed that both temperature areas had a rise in ρo and ρ1 values during and after annealing. The ΔEo and ΔE1 values in each temperature area decreased as the Mo-ion concentration increased. Furthermore, the conversion temperature gradually reduced as Mo was added. Based on these properties, the study's overall findings indicate that MoxW1-xO3 is suitable for future photonic devices and optoelectronic applications.

A statistical physics-based physicochemical study of L-phenylalanine adsorption on activated carbon.

CONTEXT: In this comparative study of the adsorption of L-phenylalanine (L-Phe) on two modified low-activated carbons (ACK and ACZ) at four temperatures (293-313 K), steric and energetic characteristics of adsorption were investigated. An advanced statistical physics multilayer model involving single-layer and double-layer adsorption scenarios was developed to interpret the L-Phe adsorption phenomenon. Modeling results indicate that two and three L-Phe layers were arranged depending on the tested adsorption systems. The estimated number of L-Phe molecules per leading adsorption site varied from 1.71 to 2.09 and from 1.76 to 1.86 for systems L-Phe-ACK and L-Phe-ACZ, respectively. The results show that a multimolecular adsorption mechanism might connect this amino acid molecule on ACZ and ACK surfaces in a non-parallel location. These parameters changed as follows, according to the adsorbed quantity at saturation analysis: Qasat (L-Phe-ACK) ˃ Qasat (L-Phe-ACZ). This indicates that ACK material was more efficient and valuable for L-Phe adsorption than ACZ. It was also shown that the adsorption capacity decreases as the temperature increases, proving the exothermicity of the adsorption process. This analytical substantiation is confirmed by calculating the binding energies, suggesting the occurrence of physical bonds between L-Phe amino acid molecules and ACK/ACZ binding sites and among L-Phe-L-Phe molecules. Pore size distribution was interpreted and calculated by applying the Kelvin theory to data from single adsorption isotherms. All used temperatures depicted a distribution of pores below 2 nm. The docking analysis involving L-Phe and the ACZ and ACK adsorbents reveal a significant resemblance in how receptors detect ligands. Consequently, the findings from the docking process confirm that the calculated binding affinities fall within the spectrum of adsorption energy. METHODS: This study analyzed the adsorption capacity of the L-Phe through a model proposed by statistical physics formalism. Molecular docking was used to determine the various types of interactions between the two activated carbons. Two aspects, including orientation of L-Phe on the site, number of molecules per site n, interaction energy, density of receptor site, and adsorption capacity, were discussed to elucidate the influence of activation on the two adsorbents.

Unveiling the photocatalytic potential of graphitic carbon nitride (g-C3N4): a state-of-the-art review.

Graphitic carbon nitride (g-C3N4)-based materials have emerged as promising photocatalysts due to their unique band structure, excellent stability, and environmental friendliness. This review provides a comprehensive and in-depth analysis of the current state of research on g-C3N4-based photocatalysts. The review summarizes several strategies to improve the photocatalytic performance of pristine g-C3N4, e.g., by creating heterojunctions, doping with non-metallic and metallic materials, co-catalyst loading, tuning catalyst morphology, metal deposition, and nitrogen-defect engineering. The review also highlights the various characterization techniques employed to elucidate the structural and physicochemical features of g-C3N4-based catalysts, as well as their applications of in photocatalytic degradation and hydrogen production, emphasizing their remarkable performance in pollutants' removal and clean energy generation. Furthermore, this review article investigates the effect of operational parameters on the catalytic activity and efficiency of g-C3N4-based catalysts, shedding light on the key factors that influence their performance. The review also provides insights into the photocatalytic pathways and reaction mechanisms involving g-C3N4 based photocatalysts. The review also identifies the research gaps and challenges in the field and presents prospects for the development and utilization of g-C3N4-based photocatalysts. Overall, this comprehensive review provides valuable insights into the synthesis, characterization, applications, and prospects of g-C3N4-based photocatalysts, offering guidance for future research and technological advancements in this rapidly growing field.

Nanomaterials-modified reverse osmosis membranes: a comprehensive review.

Because of its great efficiency and widespread application, reverse osmosis (RO) is a popular tool for water desalination and purification. However, traditional RO membranes have a short lifespan due to membrane fouling, deterioration, decreased salt rejection rate, and the low water flux with aging. As a result, membrane modification has received a lot of attention recently, with nanomaterials being extensively researched to improve membrane efficacy and lifespan. Herein, we present an in-depth analysis of recent advances of RO membranes modification utilizing nanomaterials. An overview of the various nanomaterials used for membrane modification, including metal oxides, zeolites, and carbon nanomaterials, is provided. The synthesis techniques and methods of integrating these nanomaterials into RO membranes are also discussed. The impacts of nanomaterial change on the performance of RO membranes are addressed. The underlying mechanisms responsible for RO membrane enhancements by nanomaterials, such as improved surface hydrophilicity, reduced membrane fouling via surface repulsion and anti-adhesion properties, and enhanced structural stability, are discussed. Furthermore, the review provides a critical analysis of the challenges and limitations associated with the use of nanomaterials to modify RO membranes. Overall, this review provides valuable insights into the modification of RO membranes with nanomaterials, providing a full grasp of the benefits, challenges, and future prospects of this challenging topic.

Correction: Highly selective optical sensor N/S-doped carbon quantum dots (CQDs) for the assessment of human chorionic gonadotropin ß-hCG in the serum of breast and prostate cancer patients.

[This corrects the article DOI: 10.1039/D3RA01570J.].

Correction: Novel sensor for the determination of CA 15-3 in serum of breast cancer patients based on Fe-gallic acid complex doped in modified cellulose polymer thin films.

[This corrects the article DOI: 10.1039/D3RA02495D.].

Highly selective optical sensor N/S-doped carbon quantum dots (CQDs) for the assessment of human chorionic gonadotropin ß-hCG in the serum of breast and prostate cancer patients.

A low-cost, accurate, and highly selective method was used for the assessment of the human chorionic gonadotropin ß-hCG in the serum of breast and prostate cancer patients. This method is based on enhancing the intensity of luminescence displayed by the optical sensor N/S-doped carbon dots (CQDs) upon adding different concentrations of ß-hCG. The luminescent optical sensor was synthesized and characterized through absorption and emission and is tailored to present blue luminescence at λem = 345 nm and λex = 288 nm at pH 7.8 in DMSO. The enhancement of the luminescence intensity of the N/S-doped CQDs, especially, the characteristic band at λem = 345 nm, is typically used for determining ß-hCG in different serum samples. The dynamic range is 1.35-22.95 mU mL-1, and the limit of detection (LOD) and quantitation limit of detection (LOQ) are 0.235 and 0.670 mU mL-1, respectively. This method was practical, simple, and relatively free from interference effect. It was successfully applied to measure PCT in the samples of human serum, and from this method, we can assess some biomarkers of cancer-related diseases in human body.

Novel sensor for the determination of CA 15-3 in serum of breast cancer patients based on Fe-gallic acid complex doped in modified cellulose polymer thin films.

Fe-gallic acid MOF embedded in an epoxy methyl cellulose polymer (CMC) thin film was synthesized and characterized by different micro-analytical tools such as: FE-SEM/EDX, XPS analysis, XRD analysis, FT-IR, and fluorescence spectroscopy. Fe-gallic acid MOF doped in a stable CMC polymer thin film is used as a novel sensor to identify CA 15-3 in the sera of patients suffering breast malignancy. The presence of appropriate functional groups in aqueous CA 15-3 solutions enables it to interact with the Fe-gallic acid MOF embedded in the thin film. The Fe-gallic acid MOF was found to absorb energy at 350 nm (λex) and emits radiation at 439 nm which was specifically quenched in the presence of CA 15-3 over a working concentration range of 0.05-570 U mL-1. In contrast to other CA 15-3 detection methods which suffered from electronic noise, interference and slowness, the Fe-gallic acid MOF proved its sensitivity as an economic, stable and reliable probe for the detection and determination of CA 15-3 in patients' serum samples with a detection limit of 0.01 U mL-1 at pH 7.2.

Development and validation of molnupiravir assessment in bulk powder and pharmaceutical formulation by the RP-HPLC-UV method.

An accurate, sensitive and selective RP-HPLC-UV method has been established for the estimation of Molnupiravir (MOL) in pure bulk powder and pharmaceutical formulation. Separation was achieved on an Inertsil C18 column (150.0 mm × 4.6 mm, 5.0 µm), using a mobile phase of 20 mM phosphate buffer pH 2.5 : acetonitrile (80 : 20, v/v%) in isocratic mode with a flow rate of 1.0 mL min-1. The λ max of MOL prepared in the chosen diluent (ethanol : water in equal proportions) was found to be 230.0 nm. The constructed calibration curve was found to be linear in the concentration range of 0.2-80.0 µg mL-1. The recovery% of MOL using the proposed method was 100.29%. The limit of detection (LOD) and limit of quantification (LOQ) were 0.04 µg mL-1 and 0.12 µg mL-1, respectively. No significant interference was detected in the presence of the common pharmaceutical formulation excipients. The method was validated following the ICH recommendations. All the obtained results were statistically compared with those using reported methods and there were no significant differences. The method developed in this work was successfully employed for the assessment of MOL in bulk powder and pharmaceutical formulation.

Synthesis and characterization of new 1,3,4-thiadiazole derivatives: study of their antibacterial activity and CT-DNA binding.

1,3,4-Thiadiazole molecules (1-4) were synthesized by the reaction of phenylthiosemicarbazide and methoxy cinnamic acid molecules in the presence of phosphorus oxychloride, and characterized with UV, FT-IR, 13C-NMR, and 1H-NMR methods. DFT calculations (b3lyp/6-311++G(d,p)) were performed to investigate the structures' geometry and physiochemical properties. Their antibacterial activity was screened for various bacteria strains such as Enterobacter aerogenes, Escherichia coli ATCC 13048, Salmonella kentucky, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus and Gram positive such as Staphylococcus aureus ATCC 25923, Listeria monocytogenes ATCC 7644, Enterococcus faecium, Enterococcus durans, Staphylococcus aureus ATCC, Serratia marcescens, Staphylococcus hominis, Staphylococcus epidermidis, alfa Streptococcus haemolyticus, Enterococcus faecium and found to have an inhibitory effect on Klebsiella pneumoniae and Staphylococcus hominis, while molecules 1, 3 and 4 had an inhibitory effect on Staphylococcus epidermidis and alpha Streptococcus haemolyticus. The experimental results were supported by the docking study using the Kinase ThiM from Klebsiella pneumoniae. All the investigated compounds showed an inhibitory effect for the Staphylococcus epidermidis protein. In addition, the mechanism of the 1-4 molecule interaction with calf thymus-DNA (CT-DNA) was investigated by UV-vis spectroscopic methods.

A highly selective and sensitive spectrofluorimetric method for the assessment of 3-nitrotyrosine in serum using (Eu(TTA)3Phen) photo probe.

A simple, accurate and fast method was developed for the assessment of 3-nitrotyrosine as a biomarker for the early diagnosis of liver cirrhosis with minimal hepatic encephalopathy (MHE) using a (Eu(TTA)3Phen) photo probe. 3-Nitrotyrosine can remarkably quench the luminescence intensity of the (Eu(TTA)3Phen) complex in DMSO at pH = 9 and λ em = 617 nm. The quenching of the luminescence intensity of (Eu(TTA)3Phen) complex particularly the electrical emission band at λ em = 617 nm is used for the assessment of 3-nitrotyrosine in different serum samples of patients with liver cirrhosis.

New Tb3+-simvastatin optical biosensor for sensitive determination of folic acid, progesterone, testosterone and vitamin D3 in biological fluids.

An innovative, simple and cost effective Tb3+-simvastatin photo probe was designed and used as a core for a spectrofluorometric approach to sensitively determine four vital biological compounds in different matrices. A Tb3+-simvastatin complex displays a characteristic electrical band with λ em at 545 nm with significant luminescence intensity, which is quenched in the presence of folic acid, progesterone, testosterone and vitamin D3 at four variant sets of pH: 5.0, 6.2, 7.5 and 9.0, respectively. The conditions were optimized and the best solvent for operation was found to be acetonitrile at λ ex at 340 nm. Folic acid was successfully estimated in tablet dosage form, urine and serum in the concentration range of 2.49 × 10-9 to 1.28 × 10-6 mol L-1. Progesterone, testosterone and vitamin D3 were also assessed in serum samples using the same optimal conditions within concentration ranges of 5 × 10-9 to 1.9 × 10-6, 5 × 10-9 to 2.8 × 10-6 and 5 × 10-9 to 4.2 × 10-6 mol L-1, respectively. The proposed luminescence method was validated in accordance with ICH guidelines and found to be accurate, precise, and specific and free from any interference at the working pH for each analyte. The cost effectiveness and applicability of the method make it a good choice for routine analysis of the four compounds and early diagnosis of chronic diseases associated with abnormalities in their physiological levels.

Tb3+-atorvastatin doped in poly(ethylene glycol) optical biosensor for selective determination of progesterone and testosterone in serum samples.

An innovative, simple and cost effective Tb3+-atorvastatin photo probe was designed and used as a core for a spectrofluorometric approach to sensitively determine two vital biological compounds in serum samples. Tb3+-atorvastatin complex displays a characteristic electrical band with λ em at 545 nm with significant luminescence intensity, which is quenched in the presence of progesterone and testosterone at two variant sets of pH; 6.2 and 7.5, respectively. The conditions were optimized and the best solvent for operation was found to be acetonitrile with λ ex at 320 nm. Progesterone and testosterone were assessed in serum samples using the same optimal conditions within concentration ranges of 2 × 10-9 to 2.9 × 10-6 and 3.1 × 10-9 to 4.8 × 10-6 mol L-1, respectively. The proposed luminescence method was validated in accordance to ICH guidelines and found to be accurate, precise and specific and free from any interference. The cost effectiveness and applicability of the method make it a good choice for routine analysis of the two compounds and early diagnosis of chronic diseases associated with abnormalities in their physiological levels.