Bovine serum albumin functionalized blue emitting Ti3 C2 MXene quantum dots as a sensitive fluorescence probe for Fe3+ ion detection and its toxicity analysis.

In the present work, an improved class of protein functionalized fluorescent 2D Ti3 C2 MXene quantum dots (MXene QDs) was prepared using a hydrothermal method. Exfoliated 2D Ti3 C2 sheets were used as the starting precursor and transport protein bovine serum albumin (BSA) was used to functionalize the MXene QDs. BSA-functionalized MXene QDs exhibited excellent photophysical property and stability at various physiological parameters. High-resolution transmission electron microscopy analysis showed that the BSA@MXene QDs were quasispherical in shape with a size of ~2 nm. The fluorescence intensity of BSA@MXene QDs was selectively quenched in the presence of Fe3+ ions. The mechanism of fluorescence quenching was further substantiated using time-resolved fluorescence and Stern-Volmer analysis. The sensing assay showed a linear response within the concentration range 0-150 µM of Fe3+ ions with excellent limit of detection. BSA@MXene QDs probe showed good selectivity toward ferric ions even in the presence of other potential interferences. The practical applicability of BSA@MXene QDs was further tested in real samples for Fe3+ ion quantification and the sensor had good recovery rates. The cytotoxicity studies of the BSA@MXene QDs toward the human glioblastoma cells revealed that BSA@MXene QDs are biocompatible at lower doses and showed significant cytotoxicity at higher dosages.

Development of photoluminescent, superhydrophobic, and electrically conductive cotton fibres.

A simple method for the preparation of multifunctional nanocomposite was developed towards the production of water-repellent, electrically conductive, and photoluminescent film onto cotton fibres. The nanocomposite was composed of lanthanide-doped strontium aluminium oxide and silicon rubber dispersed in petroleum ether. The electrically conductive fabric was woven from nickel strips twisted with cotton filaments as core yarns, which were wrapped with pure cotton yarns. The nanoparticles (NPs) of lanthanide-doped strontium aluminium oxide were mixed with environmentally friendly room-temperature vulcanizing silicon rubber (RTV-SR) dissolved in petroleum ether to give the silicon rubber/strontium aluminate nanocomposites. The produced nanocomposites were applied onto electrically conductive cotton/nickel fibres using spray-coating technology. The surface of the cotton/nickel fibres showed different hierarchical morphologies depending on the total content of the silicon rubber. Additionally, the superhydrophobic effect was found to be improved upon increasing the total content of the luminescence pigment NPs. The morphologies of the prepared phosphor NPs were determined using transmission electron microscopy (TEM). The generated transparent luminescence film demonstrated an absorbance peak at 358 nm and an emission peak at 515 nm. Photoluminescence of cotton fibres was monitored with the generation of different colours, including grey, green-yellow, bright white, and turquoise shades as recognized using CIE Laboratory colorimetric parameters. The emission, excitation, lifetime, and decay time spectra of the phosphorescent spray-coated cotton samples were studied. The surface morphologies and chemical compositions of the spray-coated cotton/nickel were investigated using wavelength-dispersive X-ray fluorescence (WD-XRF), scanning electron microscope (SEM), Fourier-transform infrared spectra (FTIR), and energy-dispersive X-ray analyzer (EDAX). The superhydrophobic effects were characterized by measuring static water contact angle. The comfort characteristics of the treated cotton/nickel substrates were assessed by investigating their air permeability and stiffness. The treated cotton/nickel fabrics also displayed an antimicrobial activity. The results displayed water repellence with high electrical conductivity and photoluminescence properties.

Parents' Knowledge, Attitude, and Practices toward Methamphetamine Abuse among Youth and its Risk Factors in Saudi Arabia.

Objective: The present study aimed to conduct an assessment of parents' knowledge, attitudes, and practices toward methamphetamine "shabu" abuse among youth and its risk factors. Materials and Methods: The present cross-sectional descriptive study was conducted on a sample of 1179 parents. Parents were assured that questionnaire content would stay classified and was given anonymously. It had 20 demographic, drug use, and addiction treatment questions. Statistical Package for Social Sciences v. 24 and Chi-Square test were used to examine the data after evaluating and coding it. Results: Out of a total of 1179 participants, only 11% had not heard about shabu, about 38% did not know the main symptoms of crystal addiction, and 46% did not know the long side effects of crystal addiction. The majority of participants mentioned that shabu is available in powder format (57%) or liquid (13%), while 27% did not know its form. Most of the participants (97%) think that the drug of shabu or crystal or ice is dangerous; about 60% of participants mentioned that there is an addict in the family. Conclusion: Parents have good knowledge levels regarding different aspects of methamphetamine or shabu abuse, symptoms, and its risk factors. Further in-depth studies are needed at whole Saudi Arabia.

Facile synthesis of new metal-organic framework/chitosan composite sponge for Hg(II) removal: Characterization, adsorption efficiency, and optimization using Box-Behnken design.

The objective of this research was to develop a novel adsorbent to eliminate mercury (Hg(II)) from water. A unique citrate-crosslinked La-MOF/citrate crosslinked chitosan composite sponge (La-MOF@CSC composite sponge) was successfully synthesized in an acidic environment using a one-step technique. Modifying the composition of adsorbent materials is a commonly employed strategy to enhance adsorption capacity, particularly for materials composed of metal-organic frameworks. The study investigated the impact of the composite sponge on the adsorption and removal of Hg(II). The composite sponge exhibited a maximum adsorption capacity (qmax) for Hg(II) at 765.22 mg/g and an impressive high surface area of 1208 m2/g. Various factors influencing the adsorption capacity were taken into account in this study. The adsorption isotherm and kinetics were modeled using Langmuir and pseudo-second-order equations, respectively. Consistent with thermodynamics, the adsorption process was identified as spontaneous and endothermic. The quantities of adsorbed substances increased with rising temperature. The La-MOF@CSC composite sponge demonstrated the ability to be reused up to five times with satisfactory efficiency, retaining its chemical composition and exhibiting similar XRD and XPS data before and after each reuse. The interaction between heavy metals and the La-MOF/CSC composite sponge was examined. Optimization of the adsorption outcomes was conducted using the Box-Behnken design (BBD).

Magnetic biopolymers' nanocomposites from chitosan, lignin and phycosynthesized iron nanoparticles to remediate water from polluting oil.

Targeting the remediation of oil pollution in water, the construction of super magnetic adsorbent nanocomposites (NCs) was achieved using the nanoparticles of chitosan (Cht), lignin (Lg) and phycosynthesized iron nanoparticles (Fe MNPs) using Gelidium amansii extract. The syntheses and conjugations of nanomaterials were authenticated via infrared spectral analysis and the structural physiognomies of them were appraised via electron microscopy and zeta analysis. The Lg NPs, Cht NPs, Fe MNPs and their composites (Lg/Cht MNCs) had mean particles' sizes of 42.3, 76.4, 14.2 and 108.3 nm, and were charged with - 32.7, + 41.2, + 28.4 and +37.5 mV, respectively. The magnetometer revealed the high magnetic properties of both Fe MNPs and Lg/Cht MNCs; the maximum swelling of Lg/Cht NPs (46.3 %), and Lg/Cht MNPs (33.8 %) was detected after 175 min. The diesel oil adsorption experiments with Lg/Cht MNPs, using batch adsorption practices, revealed the powerful potentiality of magnetic NCs to remove oil pollution in water; the maximum adsorption capacity (qt) was achieved with the conditions of pH = 7.5, adsorption period = 90 min and adsorbent dose = 200 mg/L. The magnetic Lg/Cht MNCs exhibited excellent recovery/reusability attributes for five adsorption cycles; the qt differences were negligible after the entire oil-adsorption cycles, with oil removal of >90 %. The innovative fabricated Lg/Cht MNCs could provide an effectual, sustainable and eco-friendly approach for the removal of pollutant oil in water resources.

Novel Iron Oxide Nanoparticle-Fortified Carbon Paste Electrode for the Sensitive Voltammetric Determination of Atomoxetine.

Herein, the fabrication and full characterization of a novel atomoxetine (ATX) voltammetric carbon paste electrode (CPE) fortified with iron oxide nanoparticles (FeONPs) is demonstrated. Modification of the carbon paste matrix with the metallic oxide nanostructure provides proper electrocatalytic activity against the oxidation of ATX molecules at the carbon paste surface, resulting in a noticeable improvement in the performance of the sensor. At the recommended pH value, ATX recorded an irreversible anodic peak at 1.17 V, following a diffusion-controlled reaction mechanism. Differential pulse voltammograms exhibited peak heights linearly correlated to the ATX content within a wide concentration range from 45 to 8680 ng mL-1, with the limit of detection reaching 11.55 ng mL-1. The electrooxidation mechanism of the ATX molecule was proposed to be the oxidation of the terminal amino group accompanied by the transfer of two electrons and two protons. The fabricated FeONPs/CPE sensors exhibited enhanced selectivity and sensitivity and therefore can be introduced for voltammetric assaying of atomoxetine-indifferent pharmaceutical and biological samples in the presence of its degradation products and metabolites.

Kappa-carrageenan for benign preparation of CdSeNPs enhancing the electrochemical measurement of AC symmetric supercapacitor device based on neutral aqueous electrolyte.

This study presents the development of an electrochemical supercapacitor with a cadmium selenide nanoparticles (CdSeNPs) electrode utilizing a straightforward and economical method based on kappa-carrageenan (κ-CGN). The structural, morphological, and optical characteristics of CdSeNPs were assessed. Activated carbon (AC) and green-prepared CdSeNPs were easily mixed to achieve excellent electrochemical properties. The nanoelectrode (AC@CdSe) was tested in an aqueous electrolyte of sodium sulfate (Na2SO4) with a concentration of 1 Molar. Specific capacitance (Csp) for the AC electrode and the AC@CdSe electrode at 1 A g-1 was calculated to be 103 and 480 F g-1, respectively. Besides, the symmetric supercapacitor AC@CdSe/AC@CdSe device has a high specific energy of 52 Wh kg-1 and a maximum specific power of 2880 W kg-1, with a specific capacitance of 115.5 F g-1. With a coulombic efficiency of between 82 % and 100 %, the device continues to maintain excellent capacitance after 10.000 cycles.

Correction: Almutairi et al. Application of Chitosan/Alginate Nanocomposite Incorporated with Phycosynthesized Iron Nanoparticles for Efficient Remediation of Chromium. Polymers 2021, 13, 2481.

The authors wish to make the following corrections to the published paper [...].

Carboxymethyl cellulose mediated growth of V2O5 nanorod by green strategy for energy storage utilization using electrochemical studies.

Vanadium pentoxide has the most exciting oxidation states, but, Vanadium pentoxide (V2O5) has low capacitance due to poor electrical conductivity and ionic diffusivity. So, encapsulating pentoxide in carbonaceous materials or metals, shrinking it to the nanoscale, or changing its morphology can improve capacitance performance. Herein, we describe a green synthesis of V2O5NPs with carboxymethyl cellulose (CMC) that typically acts as a reducing and stabilizing agent using the -COOH and -OH group. The physicochemical characterization of prepared samples reveals the prominent peak in UV-vis spectra at 265 nm confirming the formation of V2O5NPs with particle sizes between 200 and 220 nm. The theoretical surface area for the nanocomposite was 76.5 m2/g. The calcination temperature is essential to determine a material's specific capacitance. Due to decreased oxide agglomeration, the V2O5-green modified electrode exhibits superior electrochemical performance around 223 F g-1 than Ac alone (160 F g-1). The finding demonstrated excellent cyclic stability with reduced fluctuation in capacitance. Because of its exceptional electrochemical performance and simplicity of access, this AC/V2O5 nanocomposite can be helpful as an electrode for energy storage applications.

Spectral, Molecular Modeling, and Biological Activity Studies on New Schiff's Base of Acenaphthaquinone Transition Metal Complexes.

The newly synthesized Schiff's base derivative, N-allyl-2-(2-oxoacenaphthylen-1(2H)-ylidene)hydrazine-1-carbothioamide, has been characterized by different spectral techniques. Its reaction with Co(II), Ni(II), and Zn(II) acetate led to the formation of 1 : 1 (M:L) complexes. The IR and NMR spectral data revealed keto-thione form for the free ligand. On chelation with Co(II) and Ni(II), it behaved as mononegative and neutral tridentate via O, N1, and S donors, respectively, while it showed neutral bidentate mode via O and N1 atoms with Zn(II). The electronic spectra indicated that all the isolated complexes have an octahedral structure. The thermal gravimetric analyses confirmed the suggested formula and the presence of coordinated water molecules. The XRD pattern of the metal complexes showed that both Co(II) and Ni(II) have amorphous nature, while Zn(II) complex has monoclinic crystallinity with an average size of 9.10 nm. DFT modeling of the ligand and complexes supported the proposed structures. The calculated HOMO-LUMO energy gap, ΔEH-L, of the ligand complexes was 1.96-2.49 eV range where HAAT < Zn(II) < Ni(II) < Co(II). The antioxidant activity investigation showed that the ligand and Zn(II) complex have high activity than other complexes, 88.5 and 88.6%, respectively. Accordingly, the antitumor activity of isolated compounds was examined against the hepatocellular carcinoma cell line (HepG2), where both HAAT and Zn(II) complex exhibited very strong activity, IC50 6.45 ± 0.25 and 6.39 ± 0.18 µM, respectively.

Application of Chitosan/Alginate Nanocomposite Incorporated with Phycosynthesized Iron Nanoparticles for Efficient Remediation of Chromium.

Biopolymers and nanomaterials are ideal candidates for environmental remediation and heavy metal removal. As hexavalent chromium (Cr6+) is a hazardous toxic pollutant of water, this study innovatively aimed to synthesize nanopolymer composites and load them with phycosynthesized Fe nanoparticles for the full Cr6+ removal from aqueous solutions. The extraction of chitosan (Cht) from prawn shells and alginate (Alg) from brown seaweed (Sargassum linifolium) was achieved with standard characteristics. The tow biopolymers were combined and cross-linked (via microemulsion protocol) to generate nanoparticles from their composites (Cht/Alg NPs), which had a mean diameter of 311.2 nm and were negatively charged (-23.2 mV). The phycosynthesis of iron nanoparticles (Fe-NPs) was additionally attained using S. linifolium extract (SE), and the Fe-NPs had semispherical shapes with a 21.4 nm mean diameter. The conjugation of Cht/Alg NPs with SE-phycosynthesized Fe-NPs resulted in homogenous distribution and stabilization of metal NPs within the polymer nanocomposites. Both nanocomposites exhibited high efficiency as adsorbents for Cr6+ at diverse conditions (e.g., pH, adsorbent dose, contact time and initial ion concentration) using batch adsorption evaluation; the most effectual conditions for adsorption were a pH value of 5.0, adsorbent dose of 4 g/L, contact time of 210 min and initial Cr6+ concentration of 75 ppm. These factors could result in full removal of Cr6+ from batch experiments. The composited nanopolymers (Cht/Alg NPs) incorporated with SE-phycosynthesized Fe-NPs are strongly recommended for complete removal of Cr6+ from aqueous environments.