Electrostatically Assembled Multilayered Films of Biopolymer Enhanced Nanocapsules for on-Demand Drug Release

Glycan-based scaffolds and nanoparticles as drug delivery system in cancer therapy

Glycan-based scaffolds are unique in their high specificity, versatility, low immunogenicity, and ability to mimic natural carbohydrates, making them attractive candidates for use in cancer treatment. These scaffolds are made up of glycans, which are biopolymers with well biocompatibility in the human body that can be used for drug delivery. The versatility of glycan-based scaffolds allows for the modulation of drug activity and targeted delivery to specific cells or tissues, which increases the potency of drugs and reduces side effects. Despite their promise, there are still technical challenges in the design and production of glycan-based scaffolds, as well as limitations in their therapeutic efficacy and specificity.

Stimuli-triggered multilayer films in response to temperature and ionic strength changes for controlled favipiravir drug release

The block copolymer micelles and natural biopolymers were utilized to form layer-by-layer (LbL) films via electrostatic interaction, which were able to effectively load and controllably release favipiravir, a potential drug for the treatment of coronavirus epidemic. The LbL films demonstrated reversible swelling/shrinking behavior along with the manipulation of temperature, which could also maintain the integrity in the structure and the morphology. Due to dehydration of environmentally responsive building blocks, the drug release rate from the films was decelerated by elevating environmental temperature and ionic strength. In addition, the pulsed release of favipiravir was observed from the multilayer films under the trigger of temperature, which ensured the precise control in the content of the therapeutic reagents at a desired time point. The nanoparticle-based LbL films could be used for on-demandin vitrorelease of chemotherapeutic reagents.

Synthesis of magnetic chitosan/hyaluronic acid/κ-carrageenan nanocarriers for drug delivery

The magnetic nanocarriers containing chitosan/hyaluronic acid complexed with κ-carrageenan were synthesized by solution method, as the drug delivery system. Doxorubicin (DOX) was used as the model drug. Characterization assessments were performed to identify the functional groups, determine the structure and morphology, and magnetic properties of nanodelivery system. Furthermore, their impacts on MCF-7 and MDA-MB-237 cell lines were evaluated by MTT assay. Analyses confirm polymers physical interaction, chemical bonding in the structure, moreover presence of spherical shape magnetic nanoparticles in the 100-150 nm range. The DOX loading was 74.1 ± 2.5 %. Results indicate that the drug loading was raised to 83.0±2.2 % by increasing the amount of κ-carrageenan in specimens. The swelling of samples in the acidic environment (e.g. pH 5.5) was verified by the Dynamic Light Scattering analysis. Consequently, pH stimulus-responsive drug release in the sustained stream and a considerable amount of DOX release (84±3.1 %) was detected as compared to a higher pH medium (27±1.5 % at pH 7.4). According to the MTT assay results, MNPs showed no inhibitory effect on both cell lines. Also, 10 and 15 μg/ml of MNPs-DOX was considered as IC50 value on MDA-MB-237 and MCF-7 cells, respectively. The DOX 25 μg/ml caused 50 % antiproliferative activity in both cell lines.

Preparation of polysaccharide-based nanoparticles by chitosan and flaxseed gum polyelectrolyte complexation as carriers for bighead carp (Aristichthys nobilis) peptide delivery

Polysaccharide-based nanoparticles formed by the polyelectrolyte complexation between chitosan (CS) and flaxseed gum (FG) was developed in this work, and it was further used as a carrier for bighead carp peptide (BCP) delivery. The CS molecular weight (MW) of 50 kDa and CS/FG mass ratio of 1:2 at pH 3.5 were optimal conditions for the NP preparation, with the minimum particle size (∼155.1 nm) and the maximum BCP encapsulation efficiency (60.3 %). The BCP-loaded CS/FG NPs exhibited the smallest particle size (175.8 nm). Both CS/FG NPs and CS/FG-BCP NPs exhibited roughly uniform spherical shape. FT-IR spectra confirmed the existence of hydrogen bonds and electrostatic interactions in the nanoparticles. The BCP-loaded NPs displayed a higher thermal stability than BCP. Moreover, the release of BCP was controllable and dose-dependent, following a first-order kinetics model. These findings suggested that our CS/FG NPs are a promising carrier for bioactive peptide delivery.

Diffusion-Limited Processes in Hydrogels with Chosen Applications from Drug Delivery to Electronic Components

Diffusion is one of the key nature processes which plays an important role in respiration, digestion, and nutrient transport in cells. In this regard, the present article aims to review various diffusion approaches used to fabricate different functional materials based on hydrogels, unique examples of materials that control diffusion. They have found applications in fields such as drug encapsulation and delivery, nutrient delivery in agriculture, developing materials for regenerative medicine, and creating stimuli-responsive materials in soft robotics and microrobotics. In addition, mechanisms of release and drug diffusion kinetics as key tools for material design are discussed.

Probing the effect of the capping polyelectrolyte on the internal structure of Layer-by-Layer decorated nanoliposomes

HYPOTHESIS

The internal organization of polyelectrolyte layers deposited on colloidal templates plays a very important role for the potential applications of these systems as capsules for drug delivery purposes.

EXPERIMENTS

The mutual arrangement of oppositely charged polyelectrolyte layers upon their deposition on positively charged liposomes has been studied by combining up three different scattering techniques and Electronic Spin Resonance, which has provided information about the inter-layer interactions and their effect on the final structure of the capsules.

FINDINGS

The sequential deposition of oppositely charged polyelectrolytes on the external leaflet of positively charged liposomes allows modulating the organization of the obtained supramolecular structures, impacting the packing and rigidity of the obtained capsules due to the change of the ionic cross-linking of the multi-layered film as a result of the specific charge of the last deposited layer. The possibility to modulate the properties of the LbL capsules by tuning the characteristics of the last deposited layers offers a very interesting route for the design of materials for encapsulation purposes with their properties controlled almost at will by changing the number of deposited layers and their chemistry.

Effect of Surface Cleaning Process on the Wafer Bonding of Silicon and Pyrex Glass

Anodic bonding is a reliable packaging method for MEMS devices, and the surface properties of the wafer directly affect the bonding efficiency. Therefore, the surface treatment of the wafer to be bonded is necessary. Herein, the effects of three different surface cleaning processes (degreasing, piranha solution and RCA solution) on the wafer surface were investigated by atomic force microscopy, scanning electron microscopy, infrared spectroscopy, and anodic bonding experiments. The analysis showed that during the anodic bonding of the RCA solution-cleaned wafer and Pyrex glass, the bonding interface was more closely attached, and the best surface properties were obtained. The anodic bonding experiments of the wafer and Pyrex glass showed that the bonding current increased with the applied voltage, and the bonding time decreased accordingly. This was most evident in the case of RCA cleaning. The SEM images showed that as the bonding voltage increased, the bonding interface became more uniform without obvious voids. Due to the influence of the strong electric field and temperature field, an irreversible chemical reaction occurred at the bonding interface, which formed a bonding layer that was key to successful bonding.

Applications and challenges of ultra-small particle size nanoparticles in tumor therapy

With the development of nanotechnology, nanomedicines are widely used in tumor therapy. However, biological barriers in the delivery of nanoparticles still limit their application in tumor therapy. As one of the most fundamental properties of nanoparticles, particle size plays a crucial role in the process of the nanoparticles delivery process. It is difficult for large size nanoparticles with fixed size to achieve satisfactory outcomes in every process. In order to overcome the poor penetration of larger size, nanoparticles with ultra-small particle size are proposed, which are more conducive to deep tumor penetration and uniform drug distribution. In this review, the latest progresses and advantages of ultra-small nanoparticles are systematically summarized, the perspectives and challenges of ultra-small nanoparticles strategy for cancer treatment are also discussed.

Hybrid exosomes, exosome-like nanovesicles and engineered exosomes for therapeutic applications

Exosomes are endosome-derived nanovesicles involved in cellular communication. They are natural nanocarriers secreted by various cells, making them suitable candidates for diverse drug delivery and therapeutic applications from a material standpoint. They have a phospholipid bilayer decorated with functional molecules and an enclosed parental matrix, which has attracted interest in developing designer/hybrid engineered exosome nanocarriers. The structural versatility of exosomes allows the modification of their original configuration using various methods, including genetic engineering, chemical procedures, physical techniques, and microfluidic technology, to load exosomes with additional cargo for expanded biomedical applications. Exosomes show enormous potential for overcoming the limitations of conventional nanoparticle-based techniques in targeted therapy. This review highlights the exosome sources, characteristics, state of the art in the field of hybrid exosomes, exosome-like nanovesicles and engineered exosomes as potential cargo delivery vehicles for therapeutic applications.

Sulfamic acid grafted to cross-linked chitosan by dendritic units: a bio-based, highly efficient and heterogeneous organocatalyst for green synthesis of 2,3-dihydroquinazoline derivatives

In this work, novel cross-linked chitosan by the G1 dendrimer from condensation of melamine and toluene-2,4-diisocyante terminated by sulfamic acid groups (CS-TDI-Me-TDI-NHSO₃H), as a bio-based and heterogeneous acidic organocatalyst, was designed and prepared. Also, the structure of the prepared organocatalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and thermogravimetric analysis/derivative thermogravimetry (TGA/DTA). Subsequently, the catalytic performance of the biobased and dendritic CS-TDI-Me-TDI-NHSO₃H, as a multifunctional solid acid, was evaluated for the preparation of 2,3-dihydroquinazoline derivatives through a three-component reaction by following green chemistry principles. Some of the advantages of this new protocol include high to excellent yields and short reaction times as well as easy preparation and remarkable catalyst stability of the introduced acidic organocatalyst. The CS-TDI-Me-TDI-SO₃H catalyst can be used for up to five cycles for the preparation of quinazoline derivatives with a slight decrease in its catalytic activity.

Controlled therapeutic delivery of CO from carbon monoxide-releasing molecules (CORMs)

Carbon monoxide (CO) has been regarded as a "silent killer" for its toxicity toward biological systems. However, a low concentration of endogenously produced CO has shown a number of therapeutic benefits such as anti-inflammatory, anti-proliferative, anti-apoptosis, and cytoprotective activities. Carbon monoxide-releasing molecules (CORMs) have been developed as alternatives to direct CO inhalation, which requires a specialized setting for strict dose control. CORMs are efficient CO donors, with central transition metals (such as ruthenium, iron, cobalt, and manganese) surrounded by CO as a ligand. CORMs can stably store and subsequently release their CO payload in the presence of certain triggers including solvent, light, temperature, and ligand substitution. However, CORMs require appropriate delivery strategies to improve short CO release half-life and target specificity. Herein, we highlighted the therapeutic potential of inhalation and CORMs-delivered CO. The applications of conjugate and nanocarrier systems for controlling CO release and improving therapeutic efficacy of CORMs are also described in detail. The review concludes with some of the hurdles that limit clinical translation of CORMs. Keeping in mind the tremendous potential and growing interest in CORMs, this review would be helpful for designing controlled CO release systems for clinical applications.

Steric Effects in the Deposition Mode and Drug-Delivering Efficiency of Nanocapsule-Based Multilayer Films

Using surface-initiated atom transfer radical polymerization (ATRP), block polymers with a series of quaternization degrees were coated on the surface of silica nanocapsules (SNCs) by the "grafting-from" technique. Molnupiravir, an antiviral medicine urgently approved for the treatment of SARS-CoV-2, was encapsulated in polymer-coated SNCs and further incorporated into well-defined films with polystyrene sulfonate (PSS) homopolymers by layer-by-layer (LBL) self-assembly via electrostatic interactions. We investigated the impact of the quaternization degree of the polymers and steric hindrance of functional groups on the growth mode, swelling/deswelling transition, and drug-delivering efficiency of the obtained LBL films. The SNCs were derived from coronas of parent block polymers of matched molecular weights-poly(N-isopropylacrylamide)-block-poly(N,N-dimethylaminoethyl methacrylate) (PNIPAM-b-PDMAEMA)-by quaternization with methyl sulfate. As revealed by the data results, SNCs with coronas with higher quaternization degrees resulted in a larger layering distance of the film structure because of weaker ionic pairing (due to the presence of a bulky methyl spacer) between SNCs and PSS. Interestingly, when comparing the drug release profile of the encapsulated drugs from SNC-based films, the release rate was slower in the case of capsule coronas with higher quaternization degrees because of the larger diffusion distance of the encapsulated drugs and stronger hydrophobic-hydrophobic interactions between SNCs and drug molecules.

Innovative Treatment Strategies to Accelerate Wound Healing: Trajectory and Recent Advancements

Wound healing is highly specialized dynamic multiple phase process for the repair of damaged/injured tissues through an intricate mechanism. Any failure in the normal wound healing process results in abnormal scar formation, and chronic state which is more susceptible to infections. Chronic wounds affect patients’ quality of life along with increased morbidity and mortality and are huge financial burden to healthcare systems worldwide, and thus requires specialized biomedical intensive treatment for its management. The clinical assessment and management of chronic wounds remains challenging despite the development of various therapeutic regimens owing to its painstakingly long-term treatment requirement and complex wound healing mechanism. Various conventional approaches such as cell therapy, gene therapy, growth factor delivery, wound dressings, and skin grafts etc., are being utilized for promoting wound healing in different types of wounds. However, all these abovementioned therapies are not satisfactory for all wound types, therefore, there is an urgent demand for the development of competitive therapies. Therefore, there is a pertinent requirement to develop newer and innovative treatment modalities for multipart therapeutic regimens for chronic wounds. Recent developments in advanced wound care technology includes nanotherapeutics, stem cells therapy, bioengineered skin grafts, and 3D bioprinting-based strategies for improving therapeutic outcomes with a focus on skin regeneration with minimal side effects. The main objective of this review is to provide an updated overview of progress in therapeutic options in chronic wounds healing and management over the years using next generation innovative approaches. Herein, we have discussed the skin function and anatomy, wounds and wound healing processes, followed by conventional treatment modalities for wound healing and skin regeneration. Furthermore, various emerging and innovative strategies for promoting quality wound healing such as nanotherapeutics, stem cells therapy, 3D bioprinted skin, extracellular matrix-based approaches, platelet-rich plasma-based approaches, and cold plasma treatment therapy have been discussed with their benefits and shortcomings. Finally, challenges of these innovative strategies are reviewed with a note on future prospects.

Ferric Oxide Colloid: Towards Green Nano-Fertilizer for Tomato Plant with Enhanced Vegetative Growth and Immune Response Against Fusarium Wilt Disease

Global food crisis due to climate change, pandemic COVID-19 outbreak, and Russia-Ukraine conflict leads to catastrophic consequences; almost 10 percent of the world’s population go to bed hungry daily. Narrative solution for green agriculture with high vegetation and crop yield is mandatory; novel nanomaterials can improve plant immunity and restrain plant diseases. Iron is fundamental nutrient element; it plays vital role in enzyme activity and RNA synthesis; furthermore it is involved in photosynthesis electron-transfer chains. This study reports on the facile synthesis of colloidal ferric oxide nanoparticles as novel nano-fertilizer to promote vegetation and to suppress Fusarium wilt disease in tomato plant. Disease index, protection percent, photosynthetic pigments, and metabolic indicators of resistance in plant as response to induction of systemic resistance (SR) were recorded. Results illustrated that Fe₂O₃ NPs had antifungal activity against F. oxysporum. Fe₂O₃ NPs (at 20 µg/mL) was the best treatment and reduced percent disease indexes by 15.62 and gave highly protection against disease by 82.15% relative to untreated infected plants. Fe₂O₃ NPs treatments in either (non-infected or infected) plants showed improvements in photosynthetic pigments, osmolytes, and antioxidant enzymes activity. The beneficial effects of the synthesized Fe₂O₃ NPs were extended to increase not only photosynthetic pigments, osmolytes contents but also the activities of peroxidase (POD), polyphenol oxidase (PPO), catalase (CAT) and superoxide dismutase (SOD), enzymes of the healthy and infected tomato plants in comparison with control. For, peroxidase and polyphenol oxidase activities it was found that, application of Fe₂O₃ NPs (10 µg/mL) on challenged plants offered the best treatments which increased the activities of POD by (34.4%) and PPO by (31.24%). On the other hand, application of Fe₂O₃ NPs (20 µg/mL) on challenged plants offered the best treatments which increased the activities of CAT by (30.9%), and SOD by (31.33%).

Antiviral potential of nanoparticles for the treatment of Coronavirus infections

BACKGROUND

On 31st December 2019 in Wuhan, China, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), was acknowledged. This virus spread quickly throughout the world causing a global pandemic. The World Health Organization declared COVID-19 a pandemic disease on 11th March 2020. Since then, the whole world has come together and have developed several vaccines against this deadly virus. Similarly, several alternative searches for pandemic disease therapeutics are still ongoing. One of them has been identified as nanotechnology. It has demonstrated significant promise for detecting and inhibiting a variety of viruses, including coronaviruses. Several nanoparticles, including gold nanoparticles, silver nanoparticles, quantum dots, carbon dots, graphene oxide nanoparticles, and zinc oxide nanoparticles, have previously demonstrated remarkable antiviral activity against a diverse array of viruses.

OBJECTIVE

This review aims to provide a basic and comprehensive overview of COVID-19's initial global outbreak and its mechanism of infiltration into human host cells, as well as the detailed mechanism and inhibitory effects of various nanoparticles against this virus. In addition to nanoparticles, this review focuses on the role of several antiviral drugs used against COVID-19 to date.

CONCLUSION

COVID-19 has severely disrupted the social and economic lives of people all over the world. Due to a lack of adequate medical facilities, countries have struggled to maintain control of the situation. Neither a drug nor a vaccine has a 100% efficacy rate. As a result, nanotechnology may be a better therapeutic alternative for this pandemic disease.

Unlocking the potential of drug-drug cocrystals - A comprehensive review

Intensive research subjected to the improvement of solubility and bioavailability of certain drugs has popularized the formation of cocrystals, wherein the desired drug is non-ionically bonded to a coformer by means of weak bonds. This paper addresses how crystal engineering of two compatible drug components can enhance the physicochemical and therapeutic properties of either or both of the drugs, resulting in drug-drug cocrystals, with pertinent examples. The paper also discusses the continuous screening processes which are replacing the traditional methods of crystallization due to numerous benefits to the producer as well as the products. Although faced with certain regulatory and scale-up constraints, cocrystals provide immense opportunities to the field of novel drug development.

Optimization of clofibrate with O-desmethyl anetholtrithione lead to a novel hypolipidemia compound with hepatoprotective effect

Oxidative stress and inflammation were considered to be the major mechanisms in liver damage caused by clofibrate (CF). In order to obtain lipid-lowering drugs with less liver damage, the structure of clofibrate was optimized by O-desmethyl anetholtrithione and got the target compound clofibrate-O-desmethyl anetholtrithione (CF-ATT). CF-ATT significantly reduced the levels of plasma triglycerides (TG), total cholesterol (TC) in hyperlipidemia mice induced by Triton WR-1339. In addition, CF-ATT has a significantly protective effect on the liver compared with CF. The liver weight and liver coefficient were reduced. The hepatic function indexes were also decreased, such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). Histopathological examination of the liver revealed that inflammatory cell infiltration, nuclear degeneration, cytoplasmic loosening and hepatocyte necrosis were ameliorated by administration with CF-ATT. The hepatoprotective mechanism showed that CF-ATT significantly up-regulated Nrf2 and HO-1 protein expression and down-regulated p-NF-κB P65 expression in the liver. CF-ATT has obviously antioxidant and anti-inflammatory activity. These findings suggested that CF-ATT has significant hypolipidemia activity and exact hepatoprotective effect possibly through the Nrf2/NF-κB-mediated signal pathway.

Recent advances in versatile inverse lyotropic liquid crystals

Owing to the rapid and significant progress in advanced materials and life sciences, nanotechnology is increasingly gaining in popularity. Among numerous bio-mimicking carriers, inverse lyotropic liquid crystals are known for their unique properties. These carriers make accommodation of molecules with varied characteristics achievable due to their complicated topologies. Besides, versatile symmetries of inverse LCNPs (lyotropic crystalline nanoparticles) and their aggregating bulk phases allow them to be applied in a wide range of fields including drug delivery, food, cosmetics, material sciences etc. In this review, in-depth summary, discussion and outlook for inverse lyotropic liquid crystals are provided.

Sorption of Palladium(II) from Aqueous Solution Using Diphenylthiocarbazone Immobilized onto Kieselguhr

Kieselguhr was immobilized with diphenylthiocarbazone (dithizone) and utilized as a new sorbent to extract palladium ions from an aqueous solution. The physicochemical features of the immobilized kieselguhr (K–Dz) were specified by Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and thermogravimetric analysis–differential thermal analysis. The average crystal size of the prepared material was found to be 24.41 nm. The sorption potential of the immobilized kieselguhr for the extraction of Pd(II) and La(III) in a batch mode was studied. The effects of pH, shaking time as well as the initial concentration of metals have been examined. The results demonstrate that the optimum pH was found to be 4.5 and the equilibrium was attained within 15.0 min. The adsorption kinetics and equilibrium data were well described by the pseudo-second-order kinetic model and Sips isothermal model with a maximum sorption capacity of 20.3 (mg/g). Thermodynamic parameters of the studied metal ions show that the process is spontaneous and endothermic in nature. The desorption process of Pd(II) was highly managed using acidified thiourea giving a desorption percent of approximately 80.0%. The separation possibility of Pd(II) from some metal ions such as La(III) was achieved successfully. The developed (K–Dz) composite method was applied for the recovery and separation of Pd(II) and other metal ions from a simulated automotive catalyst leachate solution. The results indicated that the (K–Dz) composite has a good reusability potential.

Polysaccharide-Based Transdermal Drug Delivery

Materials derived from natural plants and animals have great potential for transdermal drug delivery. Polysaccharides are widely derived from marine, herbal, and microbial sources. Compared with synthetic polymers, polysaccharides have the advantages of non-toxicity and biodegradability, ease of modification, biocompatibility, targeting, and antibacterial properties. Currently, polysaccharide-based transdermal drug delivery vehicles, such as hydrogel, film, microneedle (MN), and tissue scaffolds are being developed. The addition of polysaccharides allows these vehicles to exhibit better-swelling properties, mechanical strength, tensile strength, etc. Due to the stratum corneum’s resistance, the transdermal drug delivery system cannot deliver drugs as efficiently as desired. The charge and hydration of polysaccharides allow them to react with the skin and promote drug penetration. In addition, polysaccharide-based nanotechnology enhances drug utilization efficiency. Various diseases are currently treated by polysaccharide-based transdermal drug delivery devices and exhibit promising futures. The most current knowledge on these excellent materials will be thoroughly discussed by reviewing polysaccharide-based transdermal drug delivery strategies.

Effect of Oxidizer on PANI for Producing BaTiO3@PANI Perovskite Composites and Their Electrical and Electrochemical Properties

Polyaniline (PANI) has received significant attention in basic and applied studies because it has electrical and electrochemical properties comparable to conventional semiconductors and metals. PANI's electrical and electrochemical properties can be controlled through its preparation methods. Accordingly, in the present work, two different samples of PANI were prepared by the polymerization of aniline monomer via in situ polymerization method using two different oxidizers of dichromate (PANI (1)) and persulphate (PANI (2)). The products were blended with BaTiO3 (BTO) to form BTO@PANI composites. The composites were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). SEM illustrated the covering of PANI layers on the BTO nanoparticles. The electrical and electrochemical properties of the prepared composites were studied. The BTO@PANI(2) composite sample showed a conductivity of 1.2 × 10–3 S/cm higher than that found for each BTO@PANI(1) 9.1 × 10–4 S/cm and its constituents. The supercapacity showed higher capacity values of 70 F/g, and 76 F/g for BTO@PANI(1), and BTO@PANI(2), respectively, which are higher than its constituents.

Facile deposition of palladium oxide (PdO) nanoparticles on CoNi2S4microstructures towards enhanced oxygen evolution reaction

Strong demand for renewable energy resources and clean environments have inspired scientists and researchers across the globe to carry out research activities on energy provision, conversion, and storage devices. In this context, development of outperform, stable, and durable electrocatalysts has been identified as one of the major objectives for oxygen evolution reaction (OER). Herein, we offer facile approach for the deposition of few palladium oxide (PdO) nanoparticles on the cobalt-nickel bi-metallic sulphide (CoNi₂S₄) microstructures represented as PdO@ CoNi₂S₄using ultraviolet light (UV) reduction method. The morphology, crystalline structure, and chemical composition of the as-prepared PdO@ CoNi₂S₄composite were probed through scanning electron microscopy, powder x-ray diffraction, high resolution transmission electron microscopy, energy dispersive spectroscopy and x-ray photoelectron spectroscopy techniques. The combined physical characterization results revealed that ultraviolet light (UV) light promoted the facile deposition of PdO nanoparticles of 10 nm size onto the CoNi₂S₄and the fabricated PdO@ CoNi₂S₄composite has a remarkable activity towards OER in alkaline media. Significantly, it exhibited a low onset potential of 1.41 V versus reversible hydrogen electrode (RHE) and a low overpotential of 230 mV at 10 mA cm^-2. Additionally, the fabricated PdO@ CoNi₂S₄composite has a marked stability of 45 h. Electrochemical impedance spectroscopy has shown that the PdO@CoNi₂S₄composite has a low charge transfer resistance of 86.3 Ohms, which favours the OER kinetics. The PdO@ CoNi₂S₄composite provided the multiple number of active sites, which favoured the enhanced OER activity. Taken together, this new class of material could be utilized in energy conversion and storage as well as sensing applications.

Pyrroloquinoline Based Styryl Dyes Doped PMMA, PS, and PS/TiO2 Polymer for Fluorescent Applications

This article presents two highly fluorescent donor-π-acceptor (D-π-A) moieties containing an electron-donating carbazole and phenothiazine donors fused with electron-withdrawing pyrrolo-quinoline acceptor dyes, PQC and PQPT. We also discussed the polymerization and film-forming process of dye PQC and PQPT doped in poly (methyl methacrylate) (PMMA) and polystyrene (PS) polymer to find their optical applications in polymer-based technology. We investigated the fluorescent properties of dyes PQC and PQPT from 0.01 to 1 wt% in poly(methyl methacrylate) (PMMA). We also investigated the changes in the spectrum shape and shift in wavelength with changes in poly(methyl methacrylate) (PMMA), polystyrene (PS), and TiO₂ doped in polystyrene (PS/TiO₂). The analysis of surface morphology of prepared polymer samples was done with the help of a scanning electron microscope. The thermal and photostability of synthesized dyes in poly (methyl methacrylate) (PMMA), polystyrene (PS), and TiO₂ doped in polystyrene (PS/TiO₂) were investigated to get detailed information owing to the application of fluorescent polymers in the field of optoelectronic, nanohybrid coatings in solar concentrators, etc.