Harnessing spectrophotometry resolution power for determining ternary mixture for respiratory disorders treatment in their pharmaceutical formulation.

A ternary mixture incorporating Hydroxyzine hydrochloride (HYX), Ephedrine hydrochloride (EPH) and Theophylline (THP) frequently prescribed for the treatment of respiratory diseases. Herein, two spectrophotometric methods are designated and applied to resolve these three components in their mixture. Method A is ratio-subtraction combined with derivative spectrophotometry, where THP can be determined directly at its λmax 271 nm (neither HYX or EPH interfere), then for determination of HYX and EPH, the ternary mixture was divided by 22 µg/mL of THP and after subtraction of the plateau region, HYX can be determined directly at its λmax 234.2 nm (absence of EPH intervention). Finally, the third derivative (3D) spectrophotometric approach was utilized to estimate EPH by detecting the peak amplitude at 222 nm with Δλ = 4 and a scaling factor 100. Principal Component Regression (PCR) and Partial Least Squares (PLS), two multivariate calibration approaches, were applied effectively in Method B. This method effectively quantified the mixture under investigation by using the absorption spectra obtained from suitable solutions of the three components in the 210-230 nm region. The calibration models were evaluated using cross-validation with PCR and PLS, producing statistical characteristics that demonstrate the effectiveness of the calibration models. Synthetic and pharmaceutical preparations were also used to conduct external validation. In pharmaceutical formulation, these methods were successfully applied to analyze HYX, EPH, and THP without overlap from formulation's excipients. Moreover, the study's findings were statistically contrasted with those of earlier reported HPLC method. Appraisal approaches were used to determine whether the new spectrophotometric methods had an adverse environmental impact involving the Green Analytical Procedure Index (GAPI) and the AGREE (Analytical Greenness). These evaluations delivered information about the methods' eco-friendliness and sustainability, proving that they are in line with ecologically attributed practices. Furthermore, the Blue Applicability Grade Index (BAGI) was utilized to identify and verify the feasibility and practicality of the suggested approaches.

Synthesis and characterization of a crosslinked deacetylated chitin modified chicken bone waste-derived hydroxyapatite and TiO2 biocomposite for defluoridation of drinking water.

This work represents an innovative approach to the synthesis and characterization of a chitosan-based biocomposite for fluoride adsorption. The work involved the development of a biocomposite based on modified chicken bone waste-derived hydroxyapatite and TiO2. The composite was characterized using scanning electron microscopy with Energy Dispersive X-ray analysis (SEM-EDX), X-ray diffraction (XRD), Fourier-transform infrared analysis (FTIR), thermal-gravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The optimum parameters for fluoride removal were determined, and the kinetic data was better fitted to the pseudo-first-order model. The Liu equations provided a better description of the experimental adsorption isotherm data. The adsorption mechanism and the interaction of the composite with fluoride were better understood using Density Functional Theory (DFT) calculations and Non-Covalent Interactions (NCI) analyses, paving the way for more effective and efficient defluoridation methods.

High Performance Thin Layer Chromatography (HPTLC) Analysis of Anti-Asthmatic Combination Therapy in Pharmaceutical Formulation: Assessment of the Method's Greenness and Blueness.

A cost-effective, selective, sensitive, and operational TLC-densitometric approach has been adapted for the concurrent assay of Hydroxyzine Hydrochloride (HYX), Ephedrine Hydrochloride (EPH), and Theophylline (THP) in their pure powder and pharmaceutical forms. In the innovative TLC-densitometric approach, HYX, EPH, and THP were efficaciously separated and quantified on a 60F254 silica gel stationary phase with chloroform-ammonium acetate buffer (9.5:0.5, v/v) adjusted to pH 6.5 using ammonia solution as a mobile liquid system and UV detection at 220 nm. The novel TLC method validation has been performed in line with the international conference for harmonization (ICH) standards and has been effectively used for the estimation of the researched medicines in their pharmaceutical formulations without intervention from excipients. Additionally, parameters affecting the chromatographic analysis have been investigated. The new TLC approach's functionality and greenness were appraised using three modern and automated tools, namely the Blue Applicability Grade Index (BAGI), the Analytical Greenness metric (AGREE), and the Green Analytical Procedure Index (GAPI) tools. In short, the greenness characteristics were not achieved as a result of using mandatory, non-ecofriendly solvents such as ammonia and chloroform. On the contrary, the applicability and usefulness of the novel TLC approach were attained via concurrent estimation for the three drugs using simple and straightforward procedures. Moreover, the novel TLC method outperforms previously published HPLC ones in terms of the short run time per sample and moderate pH value for the liquid system. According to the conclusions of comparisons with previously recorded TLC methods, our novel HPTLC method has the highest AGREE score, so it is the greenest HPTLC strategy. Moreover, its functionality and applicability are very appropriate because of the simultaneous assessment of three drugs in one TLC run. Furthermore, no tedious and complicated extraction and evaporation processes are prerequisites.

Chemically modified graphitic carbon nitride nanosheets for the selective turn-off fluorescence detection of Al(III) ions in crabs (Brachyura).

The selective and sensitive detection of Al(III) is critically important for human health since the level of Al(III) is an indicator of many diseases in humans. Herein, we developed a simple and sensitive fluorescent sensor for the detection of Al(III) in an aqueous solution based on the fluorescence of hydroxyl-functionalized graphitic carbon nitride nanosheets (HO/g-CN). OH/g-CN nanosheets were synthesized via the thermal pyrolysis of 1,3,5-triazine-2,4,6-triamine (as raw material) at 550 °C for 2 hours, followed by thermal alkali treatment at 730 °C for 2 min. The fluorescence of HO/g-CN at 377 nm (at 290 nm excitation) can be quenched by Al(III) effectively and selectively, and the linear relationship between the concentration of Al(III) and fluorescence intensity is in the range of 1.85-14.82 µM with a detection limit of 0.272 µM. The fluorescence turn-off effect of the Al(III) ion on the prepared HO/g-CN nanosheets could be attributed to the presence of oxygen- and nitrogen-containing functional groups on the surface of HO/g-CN that have chelating interactions with Al(III), leading to quenching. The surface functional groups of OH/g-CN were confirmed using different characterization techniques (FTIR, EDX, and XPS). Moreover, the prepared HO/g-CN exhibited remarkable long-term fluorescence stability in water (>30 days) and minimal toxicity. Importantly, a prepared novel fluorescent sensor (HO/g-CN) was successfully applied for the detection and determination of Al(III) in commercially available crab (Brachyura) samples.

Enhancing the Conductivity and Dielectric Characteristics of Bismuth Oxyiodide via Activated Carbon Doping.

Activated carbon/BiOI nanocomposites were successfully synthesized through a simplistic method. The produced composites were then characterized using XRD, TEM, SEM-EDX, and XPS. The results showed that BiOI with a tetragonal crystal structure had been formed. The interaction between activated carbon and BiOI was confirmed via all the mentioned tools. The obtained nanocomposites' electrical conductivity, dielectric properties, and Ac impedance were studied at 59 KHz-1.29 MHz. AC and dc conductivities were studied at temperatures between 303 and 573 K within the frequency range of 59 KHz-1.29 MHz. The 10% activated carbon/BiOI nanocomposite possessed dc and AC conductivity values of 5.56 × 10-4 and 2.86 × 10-4 Ω-1.cm-1, respectively, which were higher than BiOI and the other nanocomposites. Every sample exhibited increased electrical conductivity values as the temperature and frequency rose, suggesting that all samples had semiconducting behavior. The loss and dielectric constants (ε' and ε″) also dropped as the frequency increased, leading to higher dielectric loss. The Nyquist plot unraveled single semicircle arcs and a decreased bulk resistance, indicating decreased grain boundary resistance. Consequently, the electrical characteristics of BiOI, 1C/BiOI, 5C/BiOI, and 10C/BiOI implied their applicability as dielectric absorbers, charge-stored capacitors, and high-frequency microwave devices.

Sorption Characteristics and Chromatographic Separation of 90Y3+ from 90Sr2+ from Aqueous Media by Chelex-100 (Anion Ion Exchange) Packed Column.

There is growing demand for separation of 90Y carrier free from 90Sr coexisting to produce high purity 90Y essential for radiopharmaceutical uses. Thus, in this context the sorption profiles of Y3+ and Sr2+ from aqueous solutions containing diethylenetriaminepenta acetic acid (DTPA), ethylenediaminetetra-acetic acid (EDTA), acetic acid, citric acid, or NaCl onto Chelex-100 (anion ion exchange) solid sorbent were critically studied for developing an efficient and low-cost methodology for selective separation of Y3+ from Sr2+ ions (1.0 × 10-5 M). Batch experiments displayed relative chemical extraction percentage (98 ± 5.4%) of Y3+ from aqueous acetic acid solution onto Chelex-100 (anion ion exchanger), whereas Sr2+ species showed no sorption. Hence, a selective separation of Y3+ from its parent 90Sr2+ has been established based upon percolation of the aqueous solution of Y3+ and Sr2+ ions containing acetic acid at pH 1-2 through Chelex-100 sorbent packed column at a 2 mL min-1 flow rate. Y3+ species were retained quantitatively while Sr2+ ions were not sorbed and passed through the sorbent packed column without extraction. The sorbed Y3+ species were then recovered from the sorbent packed column with HNO3 (1.0 M) at a 1.0 mL min-1 flow rate. A dual extraction mechanism comprising absorption associated to "weak-base anion exchanger" and "solvent extraction" of Y3+ as (YCl6)3- and an extra part for "surface adsorption" of Y3+ by the sorbent is proposed. The established method was validated by measuring the radiochemical (99.2 ± 2 1%), radionuclide purity and retardation factor (Rf = 10.0 ± 0.1 cm) of 90Y3+ recovered in the eluate. Ultimately, the sorbent packed column also presented high stability for reusing 2-3 cycles without drop in its efficiency (±5%) towards Y3+ uptake and relative chemical recovery. A proposed flow sheet describing the analytical procedures for the separation of 90Y3+ from 90Sr2+ using chelating Chelex 100 (anion exchange) packed column is also included.

Novel hybrid thiazoles, bis-thiazoles linked to azo-sulfamethoxazole: Synthesis, docking, and antimicrobial activity.

The reaction of sulfamethoxazolehydrazonoyl chloride with thiosemicarbazones, bis-thiosemicarbazones, or 4-amino-3-mercapto-1,2,4-triazole in dioxane in the presence of triethylamine as a basic catalyst at reflux resulted in the regioselective synthesis of thiazoles and bis-thiazoles linked to azo-sulfamethoxazole as novel hybrid molecules. The structures of the new compounds were confirmed using a range of spectra. Each compound's antibacterial properties were evaluated using the agar well-diffusion technique, and most of them demonstrated significant potency. In silico investigations revealed that the described compounds had strong interactions with the binding sites of MurE ligase, tyrosyl-tRNA synthetase, and dihydropteroate synthase, demonstrating inhibitory activity.

Heteroatoms-doped carbon dots as dual probes for heavy metal detection.

The utilization of l-cysteine in hydrothermal synthesis allows for the manufacture of carbon dots (CDs) that are doped with heteroatoms including oxygen, nitrogen, and sulfur (N, S, O-doped CDs). CDs have a particle size ranging from 1 to 3 nm, with an average particle size of 2.5 nm. N, S, and O-doped CDs display a blue fluorescence emission at a wavelength of 425 nm. It shows a reliance on the specific excitation wavelength between 320 and 500 nm. It has a selective quenching effect specifically with copper (Cu2+) ions when exposed to interactions with heavy metal ions, as compared to other metal ions. The assay has a limit of detection (LOD) of 2 µM and exhibits a linear correlation within the concentration range of 10-33.3 µM. The fluorescence mechanism was elucidated by employing various analytical techniques, such as transmission electron microscopy (TEM), high-resolution TEM , UV-Vis spectroscopy, zeta potential analysis, and conductometry. An analysis of the data reveals that Cu2+ ions exhibit a strong attraction to the external surface of N, S, and O-doped CDs, leading to the formation of aggregates. N, S, and O-doped CDs can be also used as probes for electrochemical investigations utilizing cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) to produce Nyquist and Bode plots. The electrochemical results offer substantiation for the interaction between Cu2+ ions and N, S, and O-doped CDs. Zero-dimensional carbon nanomaterials, i.e. CDs, can improve the detection of heavy metals using optical and electrochemical methods.

Enhanced sensitivity in electrochemical detection of ochratoxin A within food samples using ferrocene- and aptamer-tethered gold nanoparticles on disposable electrodes.

Ensuring food security is crucial for public health, and the presence of mycotoxins, produced by fungi in improperly stored processed or unprocessed food, poses a significant threat. This research introduces a novel approach - a disposable aptasensing platform designed for the detection of ochratoxin A (OTA). The platform employs gold-nanostructured screen-printed carbon electrodes functionalized with a ferrocene derivative, serving as an integrated faradaic transducing system, and an anti-OTA aptamer as a bioreceptor site. Detection relies on the ferrocene electrochemical signal changes induced by the aptamer folding in the presence of the target molecule. Remarkably sensitive, the platform detects OTA within the range of 0.5 to 70 ng mL-1 and a detection limit of 11 pg mL-1. This limit is approximately 200 times below the levels stipulated by the European Commission for agricultural commodities. Notably, the sensing device exhibits efficacy in detecting OTA in complex media, such as roasted coffee beans and wine, without the need for sample pretreatment, yielding accurate recoveries. Furthermore, while label-free electrochemical aptasensors have proliferated, this study addresses a gap in understanding the binding mechanisms of some aptasensors. To enhance the experimental findings, a theoretical study was conducted to underscore the specificity of the anti-OTA aptamer as a donor for OTA detection. The molecular docking technique was employed to unveil the key binding region of the aptamer, providing valuable insights into the aptasensor specificity.

A novel chitosan-alginate@Fe/Mn mixed oxide nanocomposite for highly efficient removal of Cr (VI) from wastewater: Experiment and adsorption mechanism.

In this study, the synthesis and experimental theoretical evaluation of a new chitosan/alginate/hydrozyapatite nanocomposite doped with Mn2 and Fe2O3 for Cr removal was reported. The physicochemical properties of the obtained materials were analyzed using the following methods: SEM-EDX, XRD, FTIR, XPS, pH drift measurements, and thermal analysis. The adsorption properties were estimated based on equilibrium and adsorption kinetics measurements. The Langmuir, Freundlich and Temkin isotherms were applied to analyze the equilibrium data. The thermodynamic analysis of adsorption isotherms was performed. A number of equations and kinetic models were used to describe the adsorption rate data, including pseudo-first (PFOE) and pseudo-second (PSOE) order kinetic equations. The obtained test results show that the synthesized biomaterial, compared to pure chitosan, is characterized by greater resistance to high temperatures. Moreover, this biomaterial had excellent adsorption properties. For the adsorption of Cr (VI), the equilibrium state was reached after 120 min, and the sorption capacity was 455.9 mg/g. In addition, DFT calculations and NCI analyses were performed to get more light on the adsorption mechanism of Cr (VI) on the prepared biocomposite.

Non-enzymatic electrochemical detection of melamine in dairy products by using CuO decorated carbon nanotubes nanocomposites.

Melamine, a typical nitrogen enriched organic compound exhibiting great potential in the industrial sector, is exploited as an adulterant to inflate protein levels in dairy products, can pose serious threats to humans and therefore necessitates its swift detection and precise quantification at its first exposure. In this investigation, sensitive and reliable sensor probes were fabricated using CuO nanoparticles and its nanocomposites (NCs) with carbon nanotubes (CNTs), carbon black (CB), and graphene oxide (GO) to promptly quantify melamine in dairy products. The optical, morphological, and structural characteristics of the CuO-CNT NCs were achieved using diverse instrumental techniques including UV-visible spectroscopy, transmission electron microscopy, X- ray diffraction, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy and etc. The fabrication of glassy carbon electrodes (GCE) was accomplished by coating CuO-CNT NCs through a binder (5 % nafion). These sensor probes demonstrated outstanding electrochemical sensor performance with CuO-CNT NCs/Nafion/GCE sensor probe in terms of very low limit of detection (0.27 nM), good linearity range (0.05-0.5 nM), and relatively high sensitivity (93.924 µA µM-1 m-2) for melamine under optimized experimental conditions. Furthermore, the performance of CuO-CNT NCs/Nafion/GCE coated sensor probes was practically validated for the selective melamine detection in the real sample analysis of commercially available milk brands, which revealed significant figures of merit in a very short response time of 10 s. From the results, it was concluded that the current study might be helpful in the development of an efficient commercial sensor based on ultra-sensitive transition metal oxides in the field of health care monitoring, food stuffs in a broader scale as well as food applications.

GC/MS and LC-MS Analysis and in-vitro Antioxidant Activity of Essential Oil and Crude Methanol Extract from the Leaves of Acacia Gerrardii Benth. Growing in Saudi Arabia.

In this study, I determined the essential oil (EO) chemical composition and crude methanol extract (ME) phytochemical profile of the leaves of Acacia gerrardii (ACGL), a plant growing in Saudi Arabia. Additionally, I assessed their in vitro antioxidant activity. The gas chromatography-mass spectrometry analysis of the EO revealed a high content of oxygenated monoterpenes (79.86 %), primarily dominated by pulegone (35.11 %), carvacrol (27.36 %), and neo-dihydrocarveol (4.67 %). The ME was analyzed by liquid chromatography-mass spectrometry to determine its qualitative chemical profile. Four organic acids, eleven phenolic compounds, sixteen flavonoids, nine terpenoids (eight triterpenoids and one diterpenoid), and one coumarin were found in the ME of ACGL. This extract was found to be dominated by 5,6,4-trihydroxy-7,3-dimethoxyflavone (39.30 %), acteoside (30.27 %), nevadensin (7.55 %), isoacteoside (3.08 %) and apiin (3.23 %), and hesperidin (2.73 %). The phenolic (TPC=127.70±1.47 mg gallic acid equivalents/g of extract) and flavonoid (TFC=85.48±0.12 mg quercetin equivalents/g of extract) contents of the ME were also assessed. The in vitro antioxidant activities of both the EO and ME were evaluated using DPPH, ABTS, and ferrous ion chelating effect assays. Compared to the positive control (vit. E and Vit. C), and both extracts exhibited excellent activity.

Gold single atom-based aptananozyme as an ultrasensitive and selective colorimetric probe for detection of thrombin and C-reactive protein.

An ultra-efficient biocatalytic peroxidase-like Au-based single-atom nanozyme (Au-SAzymes) has been synthesized from isolated Au atoms on black nitrogen doped carbon (Au-N-C) using a simple complexation-adsorption-pyrolysis method. The atomic structure of AuN4 centers in black carbon was revealed by combined high-resolution transmission electron microscopy/high-angle annular dark-field scanning transmission electron microscopy. The Au-SAzymes showed a remarkable peroxidase activity with 1.7 nM as Michaelis-Menten constant, higher than most previously reported SAzyme activity. Density functional theory and Monte Carlo calculations revealed the adsorption of H2O2 on AuN4 with formation of OH* and O*. Molecular recognition was greatly enhanced via label-free integration of thiol-terminal aptamers on the surface of single Au atoms (Aptamer/Au-SAzyme) to design off-on ultrasensitive aptananozyme-based sensor for detecting thrombin and CRP with 550 pM and 500 pg mL-1 limits of detection, respectively. The Aptamer/Au-SAzyme showed satisfactory accuracy and precision when applied to the serum and plasma of COVID-19 patients. Due to the maximum Au atom utilization, approximately 3636 samples can be run per 1 mg of gold, highlighting the commercialization potential of the developed Aptamer/Au-SAzyme approach.

Dual-state dual emission from precise chemically engineered bi-ligand MOF free from encapsulation and functionalization with self-calibration model for visual detection.

Synthesis of dual-state dual emitting metal-organic frameworks (DSDE-MOFs) is uncommon and challenging. Additionally, DSDE-MOFs can fulfil the expanding need for on-site detection due to their stability and self-reference for a variety of non-analyte variables. In the present work, a novel intrinsic DSDE of chemically engineered bi-ligand Eu-based MOF (UoZ-1) was designed. The prepared UoZ-1 spherical particles were small-sized around 10-12 nm and displayed blue (425 nm) and red fluorescence (620 nm) at both states, dispersed in liquid and in solid state, when excited at 250 nm. A ratiometry platform was developed since the red emission was quenched by the addition of folic acid and the blue emission was almost remained unaffected. In the fluorometric ratiometric-mode, a dynamic linear range was recorded from 10 to 200 µM with LOD about 0.4 µM. Visual-based detection with assistance of smartphone was developed for quantification based on RGB analysis using Color Grab App. In the visual-mode, LOD as small as 2.3 µM was recorded. By utilizing the intrinsic dual-emitting UoZ-1, highly stable, recyclable, sensitive, and selective on-site visual detection of folic acid can be achieved. UoZ-1, a DSDE-MOF with no encapsulation or functionalization requirements, exhibits great potential for diverse applications.

Ionophore-modified polyaniline-based optode for the determination of hydrogen sulfite levels in beverages, wastewater, and soil.

Sulfite is a very important species, affecting human health, plant and animal life, and environmental sustainability. In this study, for the first time, an ionophore-based ion-selective optode was constructed for hydrogen sulfite determination in beverages, such as Birell® and Sprite®, water, and soil samples; instead of normal pH-chromoionophores, polyaniline film was precipitated on a glass slide and used for the transduction of the sensation mechanism. The ionophore-modified polyaniline-based optode incorporated thiourea derivative as an ionophore and tridodecyl methyl ammonium chloride as an ion-exchanger. The optode film was prepared in situ with a modified chemical polymerization method, and it was characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction (XRD); also, FTIR spectroscopy was performed for the film before and after interaction with hydrogen sulfite for mechanism elucidation. The optode was applied in the hydrogen sulfite concentration range of 10-1 to 10-5 M with a low detection limit of 8.0 × 10-6 M and minimum interference of other interfering species, such as salicylate, iodide, and sulphide. The response mechanism was due to the ion-exchange of hydrogen sulfite with the anion exchanger, followed by the molecular recognition between thiourea ionophore and hydrogen sulfite, with concomitant redox reaction via the protonation of the polyaniline that causes a decrease in absorbance at 685 nm. The optode was applied successfully for the determination of hydrogen sulfite in real beverages, Birell® and Sprite® without any pretreatment steps. Also, it was applied successfully for the environmental monitoring of hydrogen sulfite in real wastewater and soil samples.

Sub-femtomolar capacitance-based biosensing of kanamycin using screen-printed electrodes coated with redox-active polymeric films.

An ultrasensitive capacitance-based biosensor has been developed capable of detecting the kanamycin (KAN) antibiotic at sub-femtomolar levels. The biosensor was constructed using a potential-pulse-assisted method, allowing for the layer-by-layer deposition of a melanin-like polymeric film (MLPF) on an electrode surface modified with gold nanoparticles (AuNPs). The MLPF was formed through the electrochemical polymerization of dopamine and the specific kanamycin aptamer. By optimizing the operating parameters, we achieved a label-free detection of kanamycin by monitoring the variation of pseudocapacitive properties of the MLPF-modified electrode using electrochemical impedance spectroscopy. The developed biosensor demonstrated a wide linear response ranging from 1 fM to 100 pM, with a remarkable limit of detection of 0.3 fM (S/N = 3) for kanamycin. Furthermore, the biosensor was successfully applied to detect kanamycin in milk samples, exhibiting good recovery. These findings highlight the promising potential of the aptasensor for determination of antibiotic residues and ensuring food safety. In conclusion, our ultrasensitive capacitance-based biosensor provides a reliable and efficient method for detecting trace amounts of kanamycin in dairy products. This technology can contribute to safeguarding consumer health and maintaining high food safety standards.

Chemical composition, antioxidant and anti-tyrosinase potentials of Acacia cyclops trunk bark using in vitro and in silico approaches.

The purpose of this paper was to evaluate the phytochemical profile of Acacia cyclops trunk bark methanol extract using LC-MS/MS, as well as to assess its antioxidant and anti-tyrosinase activities. Thus, total phenolic and flavonoid contents of the studied extract were established and 19 compounds were detected and quantified. In addition of their antioxidant potential against DPPH and ABTS assays, in vitro and in silico studies were adopted to evaluate tyrosinase inhibitory property of A. cyclops extract. Methanol trunk bark extract showed significant total phenolic content, antioxidant potential in terms of free radical scavenging, as well as an interesting tyrosinase inhibitory action (IC50= 05.12 ± 0.41 µg/mL). The molecular docking analysis and the drug-likeness prediction of the major selected compounds supported the significant anti-tyrosinase activity of the studied extract. The obtained results suggest that A. cyclops extract could be a promising candidate in the treatment of skin hyperpigmentation disorders.

Highly sensitive capacitance-based nitrite sensing using polydopamine/AuNPs-modified screen-printed carbon electrode.

Regulatory bodies play a crucial role in establishing limits for food additives to ensure food quality and safety of food products, as excessive usage poses risks to consumers. In the context of processed animal-based foodstuffs, nitrite is commonly utilized as a means to slow down bacterial degradation. In this study, we have successfully leveraged the redox activity of an electrochemically deposited polydopamine (pDA) film onto gold nanoparticle (AuNP)-modified screen-printed electrodes (SPCE) to develop a sensitive and versatile methodology for the detection of nitrite using redox capacitance spectroscopy. By exploiting the interaction of the AuNPs/pDA electroactive interface with the target nitrite ions, we observed distinct changes in the redox distribution, subsequently leading to modifications in the associated redox capacitance. This alteration enables the successful detection of nitrite, exhibiting a linear response within the concentration range of 10 to 500 µM, with a limit of detection of 1.98 µM (S/N = 3). Furthermore, we applied the developed sensor to analyze nitrite levels in processed meats, yielding good recoveries. These results demonstrate the potential of our approach as a promising method for routine detection of ions.

Facile synthesis and characterization of Fe3O4/analcime nanocomposite for the efficient removal of Cu(II) and Cd(II) ions from aqueous media.

In the water purification field, heavy metal pollution is a problem that causes severe risk aversion. This study aimed to examine the disposal of cadmium and copper ions from aqueous solutions by a novel Fe3O4/analcime nanocomposite. A field emission scanning electron microscope (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction were used to characterize the synthesized products. The FE-SEM images showed that the analcime and Fe3O4 samples consist of polyhedral and quasi-spherical shapes with average diameters of 923.28 and 28.57 nm, respectively. Besides, the Fe3O4/analcime nanocomposite consists of polyhedral and quasi-spherical shapes with average diameters of 1100.00 nm. The greatest uptake capability of the Fe3O4/analcime nanocomposite toward the copper and cadmium ions is 176.68 and 203.67 mg/g, respectively. The pseudo-second-order kinetic model and Langmuir equilibrium isotherm best describe the uptake of copper and cadmium ions using the Fe3O4/analcime nanocomposite. The uptake of copper and cadmium ions using the Fe3O4/analcime nanocomposite is exothermic and chemical in nature.

Adsorption and Removal of Tetrabromobisphenol A by Adsorption on Functionalized Mesoporous Silica Nanotubes: Isotherms, Kinetics, Thermodynamics, and Optimization via Box-Behnken Design.

In pursuit of environmental safety, a novel and efficient method-dispersive solid-phase extraction based on functionalized mesoporous silica nanotubes (FMSNT nanoadsorbent)-was developed to remove tetrabromobisphenol A (TBBPA) from water samples. Characterization and comprehensive analysis of the FMSNT nanoadsorbent, including maximum adsorption capacity of 815.85 mg g-1 for TBBPA and its water stability, confirmed its potential. Subsequent analysis revealed the impact of multiple factors, for instance pH, concentration, dose, ionic strength, time, and temperature, on the adsorption process. The findings revealed that the adsorption of TBBPA followed the Langmuir and pseudo-second-order kinetics models while primarily driven by hydrogen bond interactions between bromine ions or hydroxyl groups of TBBPA and amino protons around the cavity. The novel FMSNT nanoadsorbent showed high stability and efficiency even after five times of recycling. Moreover, the overall process was identified as chemisorption, endothermic, and spontaneous. Finally, the Box-Behnken design was applied to optimize the results, confirming good reusability even after five cycles.