Olive leaf extract-derived chitosan-metal nanocomposite: Green synthesis and dual antimicrobial-anticancer action.

In this study, we developed a novel nanocomposite by synthesizing zinc (ZnNPs), copper (CuNPs), and silver (AgNPs) nanoparticles using olive leaf extract and incorporating them into a chitosan polymer. This approach combines the biocompatibility of chitosan with the antimicrobial and anticancer properties of metal nanoparticles, enhanced by the phytochemical richness of olive leaf extract. The significance of our research lies in its potential to offer a biodegradable and stable alternative to conventional antibiotics and cancer treatments, particularly in combating multidrug-resistant bacteria and various cancer types. Comprehensive characterization through Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and Transmission Electron Microscopy (TEM) confirmed the successful synthesis of the nanocomposites, with an average size of ~22.6 nm. Phytochemical analysis highlighted the antioxidant-rich composition of both the olive leaf extract and the nanoparticles themselves. Functionally, the synthesized nanoparticles exhibited potent antimicrobial activity against multidrug-resistant bacterial strains, outperforming traditional antibiotics by inhibiting key resistance genes (ermC, tetX3-q, blaZ, and Ery-msrA). In anticancer assessments, the nanoparticles showed selective cytotoxicity towards cancer cells in a concentration-dependent manner, with CuNPs and AgNPs showing particularly strong anticancer effects, while demonstrating minimal toxicity towards normal cells. ZnNPs were noted for their low cytotoxicity, highlighting the safety profile of these nanoparticles. Further, the nanoparticles induced apoptosis in cancer cells, as evidenced by the modulation of oncogenes (P21, P53, and BCL2), suggesting their therapeutic potential. The findings of our study underscore the versatile applications of these biogenic nanoparticles in developing safer and more effective antimicrobial and anticancer therapies.

Enhanced photoelectrochemical water splitting by a 3D hierarchical sea urchin-like structure: ZnO nanorod arrays on TiO2hollow hemisphere.

A hierarchical sea urchin-like hybrid metal oxide nanostructure of ZnO nanorods deposited on TiO2porous hollow hemispheres with a thin zinc titanate interface layer is specifically designed and synthesized to form a combined type I straddling and type II staggered junctions. The HHSs, synthesized by electrospinning, facilitate light trapping and scattering. The ZnO nanorods offer a large surface area for improved surface oxidation kinetics. The interface layer of zinc titanate (ZnTiO3) between the TiO2HHSs and ZnO nanorods regulates the charge separation in a closely coupled hierarchy structure of ZnO/ZnTiO3/TiO2. The synergistic effects of the improved light trapping, charge separation, and fast surface reaction kinetics result in a superior photoconversion efficiency of 1.07% for the photoelectrochemical water splitting with an outstanding photocurrent density of 2.8 mA cm-2at 1.23 V versus RHE.

High Antiparasitic and Antimicrobial Performance of Biosynthesized NiO Nanoparticles via Wasted Olive Leaf Extract.

Background: Nowadays, recycling agricultural waste is of the utmost importance in the world for the production of valuable bioactive compounds and environmental protection. Olive leaf bioactive compounds have a significant potential impact on the pharmaceutical industry. These compounds possess remarkable biological characteristics, including antimicrobial, antiviral, anti-inflammatory, hypoglycemic, and antioxidant properties. Methods: The present study demonstrates a green synthetic approach for the fabrication of nickel oxide nanoparticles (NiO-olive) using aqueous wasted olive leaf extract. Calcination of NiO-olive at 500°C led to the fabrication of pure NiO nanoparticles (NiO-pure). Different techniques, such as thermal gravimetric analysis (TGA), Fourier-transform infrared spectra (FTIR), ultraviolet-visible spectra (UV-Vis), X-ray diffraction (XRD), scanning electron microscopy (SEM) fitted with energy-dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM), were used to characterize both NiO-olive and NiO-pure. The extract and nanoparticles were assessed for antiparasitic activity against adult ticks (Hyalomma dromedarii) and antimicrobial activity against Bacillus cereus, Pseudomonas aeruginosa, Aspergillus niger, and Candida albicans. Results: From XRD, the crystal sizes of NiO-olive and NiO-pure were 32.94 nm and 13.85 nm, respectively. TGA, FTIR, and EDX showed the presence of olive organic residues in NiO-olive and their absence in NiO-pure. SEM and TEM showed an asymmetrical structure of NiO-olive and a regular, semi-spherical structure of NiO-pure. UV-Vis spectra showed surface plasmon resonance of NPs. Antiparasitic activity showed the highest mortality rate of 95% observed at a concentration of 0.06 mg/mL after four days of incubation. The antimicrobial activity showed the largest inhibition zone diameter of 33 ± 0.2 mm against the Candida albicans strain. Conclusion: Nanoparticles of NiO-olive outperformed nanoparticles of NiO-pure and olive leaf extract in both antiparasitic and antimicrobial tests. These findings imply that NiO-olive may be widely used as an eco-friendly and effective antiparasitic and disinfection of sewage.

Bimetallic nanoparticles supported on Ce-BTC for highly efficient and stable reduction of nitroarenes: Towards environmental sustainability.

The development of a catalyst with a consistent and clearly defined crystal structure is crucial for establishing an efficient catalytic performance system. This study focuses on catalyzing the reduction of nitroarenes to amino-derivatives in an aquatic environment at ambient temperature, employing metallic (Au) and bimetallic (Au-Pd or Au-Ag) nanoparticles loaded on a Ce-BTC metal-organic framework using a facile sol-immobilization approach. Diverse analytical instruments, comprising SEM, TEM, XRD, FT-IR, XPS, TGA, and N2 isotherm, have been utilized to characterize the synthesized catalysts. Among the catalysts that were fabricated, Au-Pd@Ce-BTC displayed the maximum catalytic efficacy, offering a rate constant (kapp) of 0.5841 min-1, conversion percentages reaching 99.7%, and a KAF of 116.8 min-1g-1. Moreover, it exhibited remarkable recyclability over five consecutive cycles. This catalyst offers the advantages of operating under ambient reaction conditions and exhibiting tolerance to a broad range of substrates containing various functional moieties. The mechanistic understanding of nitroarene reduction and the factors contributing to the superior activity of Au-Pd/Ce-BTC are explored through spectroscopic and porosity analyses. Spectroscopic measurements indicate that the elevated Auo and Pdo/Pd2+ ratio, increased surface area, and the synergistic collaboration of the bimetallic NPs are key factors contributing to the heightened activity of Au-Pd/Ce-BTC. These findings hold significant appeal from both an industrial and academic standpoint.

Effect of Rice Husk and Wood Flour on the Structural, Mechanical, and Fire-Retardant Characteristics of Recycled High-Density Polyethylene.

Given the rising consumption of plastic products, it is becoming imperative to prioritize the recycling of plastic items as a solution to reducing plastic waste and environmental pollution. In this context, this research focuses on assessing the impact of incorporating rice husk and wood flour into recycled high-density polyethylene (rec-HDPE) to analyze its mechanical properties, flammability, and thermal stability. The combined rec-HDPE content of wood flour and rice husk varied between 0% and 20%. The rec-HDPE content of maleic anhydride grafted polyethylene (MAPE) was fixed at 3%. Mechanical characteristics such as flexural, tensile, and impact strengths were assessed. Cone calorimetry (CC) tests, limited oxygen index (LOI) tests, and horizontal and vertical burning tests were performed to determine the flammability or fire retardancy of these composites. On the other hand, to characterize the thermal characteristics of these composites, thermogravimetric analysis (TGA) was used. To further characterize the fluctuation in these characteristics, scanning electron microscopy (SEM) and infrared spectroscopy (FTIR) studies were carried out. The mechanical characteristics were found to be increased in response to adding rice husk or wood flour. An 8% increase in tensile strength and a 20% increase in elastic modulus enhancement were recorded for a 20% rice husk-added composite. SEM revealed the reason for the variation in tensile properties, based on the extent of agglomeration and the extent of uniform distribution of fillers in rec-HDPE. Following these lines, the 20% rice husk-added composite also showed a maximum increase of around 6% in its flexural strength and a maximum increase of 50% in its flexural modulus. A decrease in impact strength was recorded for rice husk and wood flour-reinforced composites, compared with unreinforced rec-HDPE. Hybrid composites displayed a lack of mechanical strength due to changes in their nature. FTIR tests were performed for a much more elaborate analysis to confirm these results. Twenty percent of rice husk-added rec-HDPE displayed the best thermal properties that were tested, based on TGA and derivative thermogravimetric (DTG) analysis. This 20% composite also displayed the best fire-retardancy characteristics according to UL 94 tests, cone calorimetry tests, and limited oxygen index tests, due to the barrier created by the silica protective layer. These tests demonstrated that the incorporation of both fillers-rice husk and wood flour-effectively enhanced the thermal, mechanical, and fire-retardant attributes of recycled HDPE.

A hybrid mesoporous composite of SnO2 and MgO for adsorption and photocatalytic degradation of anionic dye from a real industrial effluent water.

Water pollution by synthetic anionic dyes is one of the most critical ecological concerns and challenges. Therefore, there is an urgent need to find an efficient adsorbent and photocatalyst for dye removal. In the present study, we aimed to fabricate a hybrid mesoporous composite of spongy sphere-like SnO2 and three-dimensional (3D) cubic-like MgO (SnO2/MgO) as a promising adsorbent/photocatalyst to remove the anionic sunset yellow (SSY) dye from real wastewater at neutral pH conditions. The as-synthesized SnO2 and MgO composite was investigated using XRD, SEM, EDX, TEM, XPS, BET, and zeta potential. The experimental study of the SSY removal using SnO2/MgO composite was performed at different conditions, such as pH, stirring time, dose, and temperature. More than 99% of 10 mg/L SSY was effectively adsorbed from aqueous solution using 40 mg of SnO2/MgO composite at pH 7 and a stirring time of 60 min. The SSY adsorption behavior was well fitted by pseudo-second order and the Langmuir model, indicating that the SSY was chemisorbed to the composite-active sites as a monolayer. On the other hand, photocatalytic degradation process exhibited better results in terms of speed of removal and used quantity of photocatalyst, where 20 mg of SnO2/MgO composite can be used to remove > 99% of SSY dye within 30 min. Mechanism of SSY adsorption and photocatalytic degradation was discussed. In addition, elution experiments demonstrated that the SnO2/MgO composite as an SSY adsorbent could be reused for nine cycles without considerable reduction in the SSY adsorption efficiency. Therefore, this work exhibited that the mesoporous SnO2/MgO composite can be considered an effective adsorbent/photocatalyst to remove SSY dye from real industrial effluent water at neutral pH conditions.

Electrospun TiO2-GO/PAN-CA nanofiber mats: A novel material for remediation of organic contaminants and nitrophenol reduction.

The outstanding properties of nanofiber composites have made them a popular choice for various structural applications. Recently, there has been a growing interest in using electrospun nanofibers as reinforcement agents, which possess exceptional properties that can enhance the performance of these composites. Herein, TiO2-graphene oxide (GO) nanocomposite incorporated into polyacrylonitrile (PAN)/cellulose acetate (CA) nanofibers were fabricated by an effortless electrospinning technique. The chemical and structural characteristics of the resulting electrospun TiO2-GO nanofibers were examined employing diverse techniques such as XRD, FTIR, XPS, TGA, mechanical properties, and FESEM. Remediation of organic contaminants and organic transformation reactions with electrospun TiO2-GO nanofibers were performed. The results indicated that the incorporation of TiO2-GO with various TiO2/GO ratios did not affect the molecular structure of PAN-CA. Still, they did significantly increase the mean fiber diameter (234-467 nm) and the mechanical properties of the nanofibers comprising UTS, elongation, Young's modulus, and toughness compared to PAN-CA. From various ratios of TiO2/GO (0.01TiO2/0.005GO and 0.005TiO2/0.01GO) in the electrospun NFs, the nanofiber containing a high content of TiO2 showed over 97% of the initial MB dyes were degraded after 120 min of visible light exposure and the same nanofibers also, achieved 96% nitrophenol conversion to aminophenol in just 10 min with activity factor kAF value of 47.7 g-1min-1. These findings illustrate the promise of TiO2-GO/PAN-CA nanofibers for use in various structural applications, particularly in the remediation of organic contaminants from water and organic transformation reactions.

Efficient Dual-Function Catalyst: Palladium-Copper Nanoparticles Immobilized on Co-Cr LDH for Seamless Aerobic Oxidation of Benzyl Alcohol and Nitrobenzene Reduction.

Layered double hydroxides (LDHs) present exciting possibilities across various industries, ranging from catalytic applications to water remediation. By immobilizing nanoparticles, LDHs' characteristics and functionality can be enhanced, allowing for synergetic interactions that further expand their potential uses. A simple chemical method was developed to produce well-dispersed Pd-Cu NPs on a Co-Cr LDH support using a combination of in situ coprecipitation/hydrothermal and sol-immobilization techniques. The Pd-Cu@Co-Cr LDH catalysts was obtained, showing its catalytic activity in promoting the aerobic oxidation of alcohols and enabling the reduction of nitro-compounds through NaBH4 mediation. The physicochemical properties of the prepared catalyst were comprehensively investigated utilizing a range of analytical techniques, comprising FTIR, XRD, XPS, TGA, nitrogen adsorption isotherm, FESEM, and HRTEM-EDX. The findings showed the significance of immobilizing the bimetallic Pd-Cu nanoparticles on the Co-Cr LDH via an exceptional performance in the aerobic oxidation of benzyl alcohol (16% conversion, 99.9% selectivity to benzaldehyde) and the reduction of nitrobenzene (98.2% conversion, rate constant of 0.0921 min-1). The improved catalytic efficacy in benzyl alcohol oxidation and nitrobenzene reduction on the Pd-Cu@Co-Cr LDH catalyst is attributed to the uniform distribution and small size of the Pd-Cu NPs as active sites on the Co-Cr LDH surface. The prepared catalyst demonstrated exceptional stability during repeated runs. This study paves the way for multiple opportunities in tailoring, producing, and precisely controlling catalysts for various organic transformation reactions.

Managing Encapsulated Oil Extract of Date Seed Waste for High Hydroxyl Radical Scavenging Assayed via Hybrid Photo-Mediated/Spectrofluorimetric Probing.

This work addresses two research topics: the first concerns the specific/sensitive trapping of hydroxyl radicals (•OH), and the second concerns the efficacy of encapsulating natural antioxidants, potentially lengthening their preservation activity. For context, nano-titania was solar-irradiated to produce •OH, which was spectrofluorimetrically assessed, based on the selective aromatic hydroxylation of the non-fluorescent sodium terephthalate to 2-hydroxyterephthalate fluorophore. Fluorescence intensity is proportional to generated •OH. Thus, a simple/rapid indirect method was utilized to assess •OH precisely. Accordingly, novel photoluminescent system is outlined in order to assess the scavenging potentiality of •OH in date seed oil (DSO) in both its pure and encapsulated formulations (ECP-DSO), i.e., when fresh and 5 months after extraction and encapsulation, respectively. With the addition of 80 µg/mL DSO or ECP-DSO, the efficacy of •OH scavenging amounted to 25.12 and 63.39%, which increased to 68.65 and 92.72% when 200 µg/mL DSO or ECP-DSO, respectively, was added. Moreover, the IC50 of DSO and ECP-DSO is 136.6 and 62.1 µg/mL, respectively. Furthermore, DSO and ECP-DSO decreased the kinetics for producing •OH by ≈20 and 40%, respectively, relative to •OH generated in the absence of antioxidant. This demonstrates the benefits of encapsulation on the preservation activity of natural antioxidants, even after five months after extraction, in terms of its interesting activity when compared to synthetic antioxidants. The developed fluorimetric •OH probing upgrades antioxidant medicines, thus paving the way for theoretical/practical insights on mechanistic hydroxyl radical-damaging biology.

Tailoring the interfacial surfaces of tungsten and molybdenum tungsten disulfide electrodes for hybrid supercapacitors.

The layered structures of tungsten disulfide (WS2) and molybdenum tungsten disulfide (MoWS2) are considered as the most promising electrode materials for energy storage devices. Herein, MS (magnetron sputtering) is required for the deposition of WS2 and MoWS2 on the surface of the current collector to attain an optimized layer thickness. The structural morphology and topological behavior of the sputtered material were examined via X-ray diffraction and atomic force microscopy. Three-electrode assembly was used to start the electrochemical investigations to identify the most optimal and effective sample among WS2 and MoWS2. CV (cyclic voltammetry), GCD (galvanostatic charging discharging), and EIS (electro-impedance spectroscopy) techniques were employed to analyze the samples. After preparing WS2 with optimized thickness as the superior performing sample, a hybrid device was designed as WS2//AC (activated carbon). With a remarkable cyclic stability of 97% after 3000 continuous cycles, the hybrid supercapacitor generated a maximum energy density (Es) value of 42.5 W h kg-1 and 4250 W kg-1 of power density (Ps). Besides, the capacitive and diffusive contribution during the charge-discharge process and b-values were calculated by Dunn's model, which lay in the 0.5-1.0 range and the fabricated WS2 hybrid device was found to have a hybrid nature. The outstanding outcomes of WS2//AC make it suitable for future energy storage applications.

Efficient nitrophenol reduction with Noria-GO nanocomposite decorated with Pd-Cu nanoparticles.

We report a facile approach to synthesize Pd-Cu nanoparticles immobilized on a Noria-GO nanocomposite for efficient nitrophenol reduction. The unique architecture of the Noria and the hydrophilic nature of GO contribute to the improved performance and structure of the resulting nanocomposite. The simple sol-immobilization approach employed NaBH4 as a reductant and polyvinyl alcohol as a capping agent to evenly decorate small Pd-Cu nanoparticles with a diameter of 1.4 nm on the Noria-GO surface. The prepared Pd-Cu@Noria-GO nanocomposite was utilized as a nanocatalyst in converting of nitrophenol to aminophenol using NaBH4 solution. Our Pd-Cu@Noria-GO nanocomposite exhibited superior catalytic efficacy with large conversion percentages, Kapp, and KAF values of 95%, 0.225 min-1, and 225 min-1g-1, respectively. X-ray photoemission spectroscopy confirmed the oxidation state of the prepared nanoparticles, and TEM findings demonstrated the homogenous decoration of Pd-Cu NPs on the Noria-GO surface. Additionally, the durability of the Pd-Cu@Noria-GO nanocomposite shown its potential as a robust and promising material for remediating organic contaminants. Our results indicate that Pd-Cu@Noria-GO nanocomposite can be an effective and sustainable approach for mitigating the hazards associated with nitrophenols.

Chitosan Polymer Functionalized-Activated Carbon/Montmorillonite Composite for the Potential Removal of Lead Ions from Wastewater.

A simple approach for synthesizing a highly adsorbent composite was described for the uptake of heavy metal ions from wastewater. A simple approach for synthesizing a highly adsorbent composite was also described for the elimination of heavy metal ions from contaminated water. The nanocomposite was synthesized via a polymer grafting of chitosan on the activated carbon surface, followed by a stacking process with the layers of montmorillonite clay. The spectroscopic analyses were exploited to confirm the composite structure of the prepared materials. Various adsorption parameters, such as pH, initial concentration, and adsorption time, were assessed. The results showed that the adsorption capacity of the composite for Pb2+ ions increased as the pH increased until it reached pH 5.5. The maximum adsorption capacity was observed at an initial Pb2+ level of 20 mg/L and a contact time of 150 min. Kinetic models were evaluated, and the pseudo second-order model showed the best match. The adsorption isotherm data were processed by fitting the model with different isotherm behaviors, and the Langmuir isotherm was found to be the most suitable for the system. The maximum adsorption capacity for Pb2+ ion on the MMT/CS/AC composite was found to be 50 mg/g at pH 5.5. Furthermore, the composite maintained a high adsorption capability of 85% for five adsorption-desorption cycles. Overall, this composite is envisioned as an addition to the market of wastewater remediation technology due to its chemical structure, which provides influential functional groups for wastewater treatment.

Synergistic effect of gold nanoparticles anchored on conductive carbon black as an efficient electrochemical sensor for sensitive detection of anti-COVID-19 drug Favipiravir in absence and presence of co-administered drug Paracetamol.

Favipiravir (FVP) is introduced as a promising newly developed antiviral drug against the coronavirus disease 2019 (COVID-19). Therefore, the accurate determination of FVP is of great significance for quality assessment and clinical diagnosis. Herein, a novel electrochemical sensing platform for FVP based on gold nanoparticles anchored conductive carbon black (Au@CCB) modified graphite nanopowder flakes paste electrode (GNFPE) was constructed. Morphological and nanostructure properties of Au@CCB have been investigated by TEM, HRTEM, and EDX methods. The morphology and electrochemical properties of Au@CCB/GNFPE were characterized by SEM, cyclic voltammetry (CV), and EIS. The Au@CCB nanostructured modified GNFPE exhibited strong electro-catalytic ability towards the oxidation of FVP. The performance of the fabricated Au@CCB/GNFPE was examined by monitoring FVP concentrations in the absence and presence of co-administered drug paracetamol (PCT) by AdS-SWV. It was demonstrated that the proposed sensor exhibited superior sensitivity, stability, and anti-interference capability for the detection of FVP. The simultaneous determination of a binary mixture containing FVP and the co-administered drug PCT using Au@CCB/GNFPE sensor is reported for the first time. Under optimized conditions, the developed sensor exhibited sensitive voltammetric responses to FVP and PCT with low detection limits of 7.5 nM and 4.3 nM, respectively. The sensing electrode was successfully used to determine FVP and PCT simultaneously in spiked human plasma and pharmaceutical preparations, and the findings were satisfactory. Finally, the fabricated sensor exhibited high sensitivity for simultaneous detection of FVP and PCT in the presence of ascorbic acid in a real sample.

Light trapping by porous TiO2 hollow hemispheres for high efficiency photoelectrochemical water splitting.

Photocatalytic water splitting has recently received increasing attention as a green fuel source. The controlled nano-geometry of the photocatalytic material can improve light harvesting. In this study, as a proof of concept, hollow hemisphere (HHS)-based films of TiO2 material were created by a conventional electrospray method and subsequently applied for photoelectrochemical (PEC) water splitting. To preserve the morphology of the HHS structure, a hydrolysis precipitation phase separation method (HPPS) was developed. As a result, the TiO2 HHS-based thin films presented a maximum PEC water splitting efficiency of ca. 0.31%, almost two times that of the photoanode formed by TiO2 nanoparticle-based films (P25). The unique morphology and porous structure of the TiO2 HHSs with reduced charge recombination and improved light absorption are responsible for the enhanced PEC performance. Light scattering by the HHS was demonstrated with total reflection internal fluorescence microscopy (TRIFM), revealing the unique light trapping phenomenon within the HHS cavity. This work paves the way for the rational design of nanostructures for photocatalysis in fields including energy, environment, and organosynthesis.

Controllable Fabrication of Zn2+ Self-Doped TiO2 Tubular Nanocomposite for Highly Efficient Water Treatment.

Tailoring high-efficiency photocatalytic composites for various implementations is a major research topic. 1D TNTs-based nanomaterials show promise as a photocatalyst for the remediation of organic pigments in an aqueous solution. Despite this, TiO2 (TNTs) is only photoactive in the UV range due to its inherent restriction on absorption of light in the UV range. Herein, we provide a facile recipe to tailor the optical characteristics and photocatalytic activity of TNTs by incorporating Zn (II) ionic species via an ion-exchange approach in an aqueous solution. The inclusion of Zn (II) ions into the TNTs framework expands its absorption of light toward the visible light range, therefore TiO2 nanotubes shows the visible-light photo-performance. Activity performance on photocatalytic decontamination of RhB at ambient temperature demonstrates that Zn-TNTs offer considerable boosted catalytic performance compared with untreated tubular TiO2 during the illumination of visible light. RhB (10 mg L-1) degradation of around 95% was achieved at 120 min. Radical scavenger experiment demonstrated that when electron (e-) or holes (h+) scavengers are introduced to the photodegradation process, the assessment of decontamination efficacy decreased by 45% and 76%, respectively. This demonstrates a more efficient engagement of the photoexcited electrons over photogenerated holes in the photodegradation mechanism. Furthermore, there seems to be no significant decrease in the activity of the Zn-TNTs after five consecutive runs. As a result, the fabricated Zn-TNTs composite has a high economic potential in the energy and environmental domains.

Tailoring confined CdS quantum dots in polysulfone membrane for efficiently durable performance in solar-driven wastewater remediating systems.

In this work, CdS quantum dots (QDs) were successfully confined in polysulfone membrane (PSM) to develop a photoactive membrane under solar illumination that was suited in wastewater remediating system. The CdS@PSM membranes were prepared using the nonsolvent induced phase separation (NIPS) approach. Optical measurements show the confinement of CdS quantum dots (QDs) in the PS matrix within the narrowest band gap (2.41 eV) at 5 wt% loading. PS has two strong emission peaks at 411 and 432 nm due to photoelectron-hole recombination on pure PSM's surface. Adding 1 wt% CdS QDs to PSM reduced the earlier peak and blue-shifted the latter, within the appearance of three emission peaks attributed to the near band-edge emission of confined CdS QDs. Overloading CdS reduced all emission peaks. Moreover, fluorimetric monitoring of •OH radicals indicates that PSM produces the least amount of photogenerated •OH radicals while CdS@PSM(5 wt%) achieved the highest productivity. Examining the developed membranes in detoxifying methylene blue (MB) from aqueous solution of natural pH 8.1 showed weak adsorption in dark over 90 min of contact while switching to solar illumination significantly photodegrade MB where the degradation efficiency starts from 49% for pure PSM to 79% for CdS@PSM(5 wt%). Influence of pH was found crucial on photodegradation efficacy. Acidic pH 3 showed the weakest photodegradation efficacy, while the alkaline pH 12 was 18.88 times more effective. The used CdS@PSM (5 wt%) was successfully photo-renovated by soaking in 10 mL of NaOH solution under Solar illumination for 15 min to be used in 4 consecutive photodegradation cycles with insignificant decrease in efficacy. These findings are promising and could lead to a high-efficiency, sustainable photocatalytic suite.

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.

Bifunctional ratiometric sensor based on highly fluorescent nitrogen and sulfur biomass-derived carbon nanodots fabricated from manufactured dairy product as a precursor.

Novel biomass-derived carbon dots co-doped with nitrogen and sulfur were fabricated through facile and simple synthetic method from manufactured milk powder and methionine as precursors. The as-fabricated platform was used for ratiometric fluorescence sensing of Cu (II) and bisphosphonate drug risedronate sodium. The sensing platform is based on oxidation of o-phenylenediamine by Cu (II) to form 2, 3-diaminophenazine (oxidized product) with an emission peak at 557 nm. The resultant product quenched the fluorescence emission of as-fabricated carbon dots at 470 nm through Förster resonance energy transfer (FRET) and inner-filter effect (IFE). Upon addition of risedronate sodium, the formation of 2, 3-diaminophenazine was decreased as a result of Cu (II) chelation with risedronate sodium, recovering the fluorescence emission of carbon dots. The ratio of fluorescence at 470 nm and 557 nm was measured as a function of Cu (II) and risedronate sodium concentrations. The proposed sensing platform sensitively detected Cu (II) and risedronate sodium in the range of 0.01-55 µM and 5.02-883 µM with LODs (S/N = 3) of 0.003 µM and 1.48 µM, respectively. The sensing platform exhibited a good selectivity towards Cu (II) and risedronate sodium. The sensing system was used to determine Cu (II) and risedronate sodium in different sample matrices with recoveries % in the range of 99-103 % and 97.4-103.8 %, and RSDs % in the range of 1.5-3.0 % and 1.8-3.6 %, respectively.

Hydrothermal Conversion of Food Waste to Carbonaceous Solid Fuel-A Review of Recent Developments.

This review critically discussed recent developments in hydrothermal carbonization (HTC) of food waste and its valorization to solid fuel. Food waste properties and fundamentals of the HTC reactor were also covered. The review further discussed the effect of temperature, contact time, pressure, water-biomass ratio, and heating rate on the HTC of food waste on the physiochemical properties of hydrochar. Literature review of the properties of the hydrochar produced from food waste in different studies shows that it possesses elemental, proximate, and energy properties that are comparable to sub-bituminous coal and may be used directly as fuel or co-combusted with coal. This work conclusively identified the existing research gaps and provided recommendation for future investigations.

Preparation and Characterization of Modified Polysulfone with Crosslinked Chitosan-Glutaraldehyde MWCNT Nanofiltration Membranes, and Evaluation of Their Capability for Salt Rejection.

Nanofiltration membranes were successfully created using multi-walled carbon nanotubes (MWCNTs) and MWCNTs modified with amine (MWCNT-NH2) and carboxylic groups (MWCNT-COOH). Chitosan (CHIT) and chitosan−glutaraldehyde (CHIT-G) were utilized as dispersants. Sonication, SEM, and contact angle were used to characterize the as-prepared membranes. The results revealed that the type of multi-walled carbon nanotubes (MWCNT, MWCNT-COOH and MWCNT-NH2) used as the top layer had a significant impact on membrane characteristics. The lowest contact angle was 38.6 ± 8.5 for the chitosan-G/MWCNT-COOH membrane. The surface morphology of membranes changed when carbon with carboxylic or amine groups was introduced. In addition, water permeability was greater for CHIT-G/MWCNT-COOH and CHIT-G/MWCNT-NH2 membranes. The CHIT-G/MWCNT-COOH membrane had the highest water permeability (5.64 ± 0.27 L m−2 h−1 bar−1). The findings also revealed that for all membranes, the rejection of inorganic salts was in the order R(NaCl) > R(MgSO4).