Hydrazine sensors development based on a glassy carbon electrode modified with a nanostructured TiO2 films by electrochemical approach

Microchimica Acta - The authors describe a selective hydrazine sensor that is based on the use of a film of TiO2 nanoparticles faceted predominantly at the 101 and 001 sides. The hydrazine (Hyd)...     

Application of Three Ecological Assessment Tools in Examining Chromatographic Methods for the Green Analysis of a Mixture of Dopamine,Serotonin, Glutamate and GABA: A Comparative Study

The assessment of greenness of analytical protocols is of great importance now to preserve the environment. Some studies have analyzed either only the neurotransmitters, dopamine, serotonin, glutamate, and gamma-aminobutyric acid (GABA), together or with other neurotransmitters and biomarkers. However, these methods have not been investigated for their greenness and were not compared with each other to find the optimum one. Therefore, this study aims to compare seven published chromatographic methods that analyzed the four neurotransmitters and their mixtures using the National Environmental Method Index, Analytical Eco-Scale Assessment (ESA), and Green Analytical Procedure Index (GAPI). As these methods cover both qualitative and quantitative aspects, they offer better transparency. Overall, GAPI showed maximum greenness throughout the analysis. Method 6 was proven to be the method of choice for analyzing the mixture, owing to its greenness, according to NEMI, ESA, and GAPI. Additionally, method 6 has a wide scope of application (13 components can be analyzed), high sensitivity (low LOQ values), and fast analysis (low retention times, especially for glutamate and GABA).     

Investigating Antiarthritic Potential of Nanostructured Clove Oil (Syzygium aromaticum) in FCA-Induced Arthritic Rats: Pharmaceutical Action and Delivery Strategies

The combined application of clove oil in a lipid nanocarrier opens a promising avenue for bone and joints therapy. In this study, we successfully developed a tunable controlled-release lipid platform for the efficient delivery of clove oil (CO) for the treatment of rheumatoid arthritis (RA). The ultra-small nanostructured lipid carriers co-loaded with CO (CONCs) were developed through an aqueous titration method followed by microfluidization. The CONCs appeared to be spherical (particle size of 120 nm), stable (zeta potential of −27 mV), and entrapped efficiently (84.5%). In toluene:acetone:glacial acetic acid (90:9:1 percent v/v/v) solvent systems, high-performance thin layer chromatography (HPTLC) analysis revealed the primary components in CO as eugenol (R_F = 0.58). The CONCs greatly increased the therapeutic impact of CO in both in vitro and in vivo biological tests, which was further supported by excellent antiarthritic action. The CONC had an antiarthritic activity that was slightly higher than neat CO and slightly lower than standard, according to our data. The improved formulation inhibited serum lysosomal enzymes and proinflammatory cytokines while also improving hind leg function. This study provides a proof of concept to treat RA with a new strategy utilizing essential oils via nanodelivery.     

Preparation and Optimization of PEGylated Nano Graphene Oxide-Based Delivery System for Drugs with Different Molecular Structures Using Design of Experiment (DoE)

Graphene oxide (GO), due to its 2D planar structure and favorable physical and chemical properties, has been used in different fields including drug delivery. This study aimed to investigate the impact of different process parameters on the average size of drug-loaded PEGylated nano graphene oxide (NGO-PEG) particles using design of experiment (DoE) and the loading of drugs with different molecular structures on an NGO-PEG-based delivery system. GO was prepared from graphite, processed using a sonication method, and functionalized using PEG 6000. Acetaminophen (AMP), diclofenac (DIC), and methotrexate (MTX) were loaded onto NGO-PEG particles. Drug-loaded NGO-PEG was then characterized using dynamic light scattering (DLS), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), XRD. The DLS data showed that the drug-loaded NGO-PEG suspensions were in the size range of 200 nm–1.3 µm. The sonication time and the stirring rate were found to be the major process parameters which affected the average size of the drug-loaded NGO-PEG. FTIR, DSC, XRD, and SEM demonstrated that the functionalization or coating of the NGO occurred through physical interaction using PEG 6000. Methotrexate (MTX), with the highest number of aromatic rings, showed the highest loading efficiency of 95.6% compared to drugs with fewer aromatic rings (diclofenac (DIC) 70.5% and acetaminophen (AMP) 65.5%). This study suggests that GO-based nano delivery systems can be used to deliver drugs with multiple aromatic rings with a low water solubility and targeted delivery (e.g., cancer).     

Mesoporous Trimetallic PtPdRu Spheres as Superior Electrocatalysts

Mesoporous Trimetallic PtPdRu Spheres with well‐defined spherical morphology and uniformly sized pores were synthesized in an aqueous solution using ascorbic acid as the reducing agent and triblock copolymer F127 as the pore directing agent. These mesoporous PtPdRu spheres exhibited enhanced electrocatalytic activity compared to commercial Pt black, resulting in a ～4.9 times improvement in mass activity for the methanol oxidation reaction. The excellent electrocatalytic activity and stability are due to the unique mesoporous architecture and electronic landscape between different elements.     

Synthesis,characterization, multifunctional electrochemical (OGR/ORR/SCs) and photodegradable activities of ZnWO<Subscript>4</Subscript> nanobricks

Brick-shaped zinc tungstate nanoparticles have been synthesized by ecofriendly solvent-free process using molten salts. Zinc tungstate nanobricks (ZnWO₄ Nbs) were characterized by powder x-ray diffraction (PXRD), FTIR, Raman, energy dispersive and electron microscopic studies. ZnWO₄ Nbs are used as the multifunctional electrode materials to oxygen generation reactions (OGR), oxygen reduction reactions (ORR) and supercapacitors (SCs) as well as photo-catalysts in the waste-water treatment by the degradation of organic dyes. Low overpotential (?₁₀?=?0.475?V), low tafel slope (140?mV/dec), high current density (~70?mA/cm²) and good stability of the electrodes are the key results of the present studies for water electrolysis (OGR/ORR). ZnWO₄ Nbs have also shown great interest in supercapacitors with efficient charge–discharge activities in 1?M KOH. The specific capacitance and energy density of ZnWO₄ Nbs were found to be 250?F/g and 80?Wh/kg, respectively, at 5?mV/s, these values are relatively higher than that of previously reported specific capacitance and energy density value of metal tungstate nanoparticles. ZnWO₄ Nbs as the photo-catalysts work very significantly for photocatalytic degradation of aqueous MB dye solution (~85 % in 3?h) in neutral medium.

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ZnWO₄ Nanobricks show significant multifunctional electro-chemical activities in alkaline medium and photocatalytic degradation of organic dye in neutral medium.

     

Investigation of the growth parameters of hydrothermal ZnO nanowires for scale up applications

Zinc oxide nano-wires (ZnO NWs) are synthesized reproducibly with high yield via a low temperature hydrothermal technique. The influence of the growth duration time, growth temperature, zinc precursor and base concentration of Na₂CO₃ on the morphology of NWs is investigated. The growth products are characterised using scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL). SEM analysis shows that the optimum growth temperature is 140 °C and finds that length and diameter of ZnO NWs have a relationship with growth duration time and base concentrations of Na₂CO₃. In addition, it is reported that a high (～90%) yield of ZnO NWs can be synthesised via using any of three different precursors: zinc chloride, zinc acetate and zinc nitrate. TEM and XRD results indicate the high purity and the single crystalline nature of the ZnO NWs. XPS confirms the absence of sodium contaminants on the surface and indicates a near flat band surface condition. PL shows a large visible band in the yellow part of the spectrum, and a small exciton emission peak, indicating a large defect concentration, which is reduced after annealing in air.     

DNA adsorption on graphene

We study analytically the properties of the optical absorption and the spatial weak-light solitons in a quantum dot molecule system with the interdot tunneling coupling (ITC). It is shown that, for the linear case, there exists tunneling induced transparency (TIT) in the context of a weak ITC, while the TIT can be replaced by Autler-Townes splitting in the presence of a strong ITC. For the nonlinear case, it is probable to realize the spatial optical solitons even under weak light intensity. Interestingly, we find that there appears transformation behavior between the bright and dark solitons by properly turning both the ITC strength and the detuning of the probe field. Meanwhile, the transformation condition of the bright and dark solitons is obtained. Additionally it is also found that the amplitude of the solitons first descends and then rises with the increasing of ITC strength. Our results may have potential applications for nonlinear optical experiments and optical telecommunication engineering in solid systems.     

Synthesis of Hg metal complex and its application to reduce the optical band gap of polymer

This study explored a new approach to fabricate the Schiff base ligand system from both ethylenediamine and 3-chloro-2-butanone. Through coordination chemistry, the mercury Hg (II) complex was achieved from the ligand and then embedded in the polyvinyl alcohol (PVA) host using a solution casting technique to prepare polymer composites (PCs). Both UV–visible and Fourier-transform infrared (FTIR) spectroscopies highlighted the formation of the Hg (II) metal complex. These techniques confirmed the synthesis of the Hg (II) metal complex. The X-ray diffraction (XRD) pattern of the polymer composite has shown a significant enhancement in its amorphous nature compared to the pure PVA host. The thermal analysis spectra for the Hg (II) complex revealed high thermal stability. The occurrence of the complexation between the Hg (II) and host matrix of the PVA was identified from the wide shifting of UV–vis absorption and peak shifting with intensity reduction of the FTIR spectra. Tauc's method has been employed to evaluate the optical band gap, and determine the types of electronic transitions. The results have shown that the samples were exhibiting an indirect forbidden electron transition, with a significant reduction in the optical band gap of a doped sample that approaching inorganic semiconductor based-materials. In addition, the optical study has exposed the role of the Hg (II) complex in tuning the refractive index of the host polymer. Ultimately, the absorption edge was found to be shifted to the lower photon energy upon the insertion of the Hg (II) complex. The PVA doped sample displayed a substantial shift in band gap from 6.2 eV to 1.2 eV.