Search Results (509)

Glass ionomers are utilized extensively within the domain of dentistry, for instance, as provisional restorations, liners, or bases, in addition to their application as pit and fissure sealers. It is imperative that this type of material exhibits favorable physico-chemical and biological properties. The primary objective of the presented study is to modify commercial resin-modified glass ionomer (Riva Light Cure, RMGIC) by doping it with copper particles (RMGIC + Cu) and to evaluate its properties in terms of potential beneficial clinical applications. Susceptibility to adhesion of microbial species and potential antimicrobial activity was evaluated against the Candida albicans, Streptococcus mutans, and Lactobacillus rhamnosus strains. Antiviral properties were evaluated against two viruses: Herpes simplex virus type 1 and human Adenovirus 5. Cytotoxicity of the materials was assessed using Balb/3T3 mouse fibroblast cell line. Temporal fluoride release up to 168 h in water and artificial saliva of different pH levels were also measured and assessed using statistical analysis. Samples were also subjected to Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy and Fourier-Transform Raman Spectroscopy. The findings of the present study demonstrate that RMGIC + Cu displays reduced biofilm formation against the tested strains when compared to non-modified material. The influence of the Cu presence on fluoride release is most pronounced in artificial saliva with a low pH (4.5), where the difference is significantly higher in samples with Cu than in samples without it. No reduction in herpes simplex 1 titers under the influence of either material was observed, whereas both materials exhibited virucidal properties against human adenovirus 5. Commercial glass ionomer presented no cytotoxicity, while the modified biomaterial caused changes in the fibroblast culture only under the sample (slight cytotoxicity, grade 1). Considering all the acquired results, doping glass ionomer with copper may be an interesting modification enhancing antimicrobial properties of the biomaterial, but it requires further evaluation in terms of long-term cytotoxicity before further in vivo studies. Full article

This study examines the influence of key technological parameters—marking speed, raster step (Δx), pulse duration, power density, and effective energy—on the laser marking of copper using Yb-doped fiber and CuBr MOPA lasers. Two experimental setups were used: the fiber laser, with 100 ns and 200 ns pulses, and the CuBr laser with 30 ns pulses. Marking speed ranged from 10 to 80 mm/s, with raster steps from 3 to 20 µm for the fiber laser and 3 to 27 µm for the CuBr laser. The study compares different pulse durations and evaluates the impact of laser wavelength on the marking process. Optimal effective energy ranges were identified: 17.4–43.1 kJ/cm² for the Yb-doped fiber laser and 9.90–43.1 kJ/cm² for the CuBr laser. The originality of this work lies in its direct comparison of Yb-doped fiber and CuBr MOPA lasers for copper marking, alongside the simultaneous optimization of multiple parameters. The study provides novel guidelines for high-contrast copper marking, a material with known laser-processing challenges. The identified optimal energy ranges and process parameters can significantly improve the efficiency and quality of industrial copper marking applications. Full article

The ion doping of hydroxyapatite (HA) has gained appeal as a chemical method of improving and adding new characteristics to materials used in biomedical engineering. Dimension, morphology, porosity, surface charge, topology, composition, and other material characteristics make doped HA more suitable for specific biomedical applications. The main aim of this review study was to highlight the role of iHA (iHA) in developing drug delivery systems, tissue engineering, implant coating, wound healing, and multimodal imaging. To the best of our knowledge, depending on the dopant, iHA can have inherent distinct mechanical, physicochemical, and biological properties that make it eligible for biomedical application. More importantly, some ions make iHA a potent antibacterial agent and drug carrier for wound healing (e.g., silver, copper, zinc), have tissue engineering capabilities, improved proangiogenic and osteoconductive properties (e.g., strontium, cobalt, nickel), drug loading capacity (e.g., magnesium, ferric, strontium), metallic implant coating properties (e.g., manganese, silver, copper), and multimodal imaging potential (e.g., terbium, ytterbium, cerium). The concentration of ions and the number of dopants played a vital role in developing new approaches based on iHA. In conclusion, iHA, compared to HA, could show better improvements in biomedical applications. Full article

This review examines the emerging role of manganese-based nanoparticles (Mn-NPs) in detecting heavy metal pollutants in environmental matrices. Heavy metals such as cadmium, lead, zinc, and copper pose serious environmental and health concerns due to their tendency to persist in ecosystems and accumulate in living organisms. As a result, there is a growing need for reliable methods to detect and remove these pollutants. Manganese nanoparticles offer unique advantages that scientists could consider as replacing other metal nanoparticles, which may be more expensive or more toxic. The physicochemical properties of Mn-NPs—including their multiple oxidation states, magnetic susceptibility, catalytic capabilities, and semiconductor conductivity—enable the development of multi-modal sensing platforms with exceptional sensitivity and selectivity. While Mn-NPs exhibit inherently low electrical conductivity, strategies such as transition metal doping and the formation of composites with conductive materials have successfully addressed this limitation. Compared to noble metal nanoparticles (Au, Ag, Pd) and other base metal nanoparticles (Bi, Fe₃O₄), Mn-NPs demonstrate competitive performance without the drawbacks of high cost, complex synthesis, poor distribution control, or significant aggregation. Preliminary studies retrieved from the Scopus database highlight promising applications of manganese-based nanomaterials in electrochemical sensing of heavy metals, with recent developments showing detection limits in the sub-ppb range. Future research directions should focus on addressing challenges related to scalability, cost-effectiveness, and integration with existing water treatment infrastructure to accelerate the transition from laboratory findings to practical environmental applications. Full article

The increasing demand for smart bone substitutes has boosted the implementation of biomaterials possibly endowed with both pro-osteogenic and pro-angiogenic capabilities, among which bioactive glasses hold great potential. Hence, two Poly(ε-caprolactone) (PCL)-based composites were loaded at 10 wt.%, with either pristine (SBA3) or copper-doped (SBA3_Cu) silica-based bioactive glasses, through a solvent casting method with chloroform. Neat PCL was used as a control. Samples produced by 3D printing underwent SEM and EDX analyses, and the following were measured: tensile strength and hardness, surface roughness, ion release through ICP-OES, surface free energy, and optical contact angle. Adipose-derived mesenchymal stem cells (ASCs) and human microvascular endothelial cells (HMEC-1) were used to test the biocompatibility of the materials through cell adhesion, spreading, and viability assays. A significant improvement in tensile strength and hardness was observed especially with Cu-doped composites. Both SBA3 and SBA3_Cu added to the PCL favored the early adhesion and the proliferation of HMEC-1 after 3 and 7 days, while ASCs proliferated significantly the most on the SBA-containing composite, at all the time points. Cellular morphology analysis highlighted interesting adaptation patterns to the samples. Further biological characterizations are needed to understand thoroughly how specific bioactive glasses may interact with different cellular types. Full article

We present a dual-mode optical sensing strategy for selective and sensitive detection of sulfide ions (S²⁻), employing copper-anchored nitrogen-doped graphene quantum dots (Cu@N-GQDs) as bifunctional nanozymes. The Cu@N-GQDs were synthesized via citric acid pyrolysis in the presence of ammonium hydroxide (serving as both nitrogen source and reductant) and copper chloride, leading to uniform incorporation of copper oxide species onto the N-GQD surface. The resulting nanohybrids exhibit two synergistic functionalities: intrinsic fluorescence comparable to pristine N-GQDs, and significantly enhanced peroxidase-like catalytic activity attributed to the anchored copper species. Upon interaction with sulfide ions, the system undergoes a dual-optical response: (i) fluorescence quenching via Cu-S complexation, and (ii) inhibition of peroxidase-like activity due to the deactivation of Cu catalytic centers via the interaction with S²⁻. This dual-signal strategy enables sensitive quantification of S²⁻, achieving detection limits of 0.5 µM (fluorescence) and 3.5 µM (colorimetry). The sensor demonstrates excellent selectivity over competing substances and high reliability and precision in real tap water samples. These findings highlight the potential of Cu@N-GQDs as robust, bifunctional, and field-deployable nanozyme probes for environmental and biomedical sulfide ion monitoring. Full article

One of the main challenges in hydroxyapatite research is to develop cost-effective synthesis methods that consistently produce materials closely resembling natural bone, while maintaining high biocompatibility, phase purity, and mechanical stability for biomedical applications. Traditional synthetic techniques frequently fail to provide desirable mechanical characteristics and antibacterial activity, necessitating the development of novel strategies based on natural precursors and selective ion doping. The present study aims to explore the possibility of synthesizing hydroxyapatite through the co-precipitation method, followed by a microwave-assisted hydrothermal maturation process. The main CaO sources selected for this study are eggshells and mussel shells. Cu²⁺ and Sr²⁺ ions were added into the hydroxyapatite structure at concentrations of 1% and 5% to investigate their potential for biomedical applications. Furthermore, the morpho-structural and biological properties have been investigated. Results demonstrated the success of hydroxyapatite synthesis and ion incorporation into its chemical structure. Moreover, HAp samples exhibited significant antimicrobial properties, especially the samples doped with 5% Cu and Sr. Additionally, all samples presented good biological activity on MC3T3-E1 osteoblast cells, demonstrating good cellular viability of all samples. Therefore, by correlating the results, it could be concluded that the undoped and doped hydroxyapatite samples are suitable biomaterials to be further applied in orthopedic applications. Full article

The most prevalent growth of Candida cells is based on biofilm development, which causes the intensification of antifungal resistance against a large range of chemicals. Nanoparticles can be synthesized using green methods via various biological extracts and reducing agents to control Candida biofilms. This study aims to compare copper oxide nanoparticles (CuONPs) synthesized through chemical methods and those synthesized using Cinnamomum verum-based green methods against Candida infections and their biofilms isolated from Iraqi patients, with the potential to improve treatment outcomes. The physical and chemical properties of these nanoparticles were characterized using Fourier-transform infrared spectroscopy (FT-IR,) scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). Four strains of Candida were isolated and characterized from Iraqi patients in Tikrit Hospital and selected based on their ability to form biofilm on polystyrene microplates. The activity of green-synthesized CuONPs using cinnamon extract was compared with both undoped and doped (Fe, Sn) chemically synthesized CuONPs. Four pathogenic Candida strains (Candida glabrata, Candida lusitaniae, Candida albicans, and Candida tropicalis) were isolated from Iraqi patients, demonstrating high biofilm formation capabilities. Chemically and green-synthesized CuONPs from Cinnamomum verum showed comparable significant antiplanktonic and antibiofilm activities against all strains. Doped CuONPs with iron or tin demonstrated lower minimum inhibitory concentration (MIC) values, indicating stronger antibacterial activity, but exhibited weaker anti-adhesive properties compared to other nanoparticles. The antiadhesive activity revealed that C. albicans strain seems to produce the most resistant biofilms while C. glabrata strain seems to be more resistant towards the doped CuONPs. Moreover, C. tropicalis was the most sensitive to all the CuONPs. Remarkably, at a concentration of 100 µg/mL, all CuONPs were effective in eradicating preformed biofilms by 47–66%. The findings suggest that CuONPs could be effective in controlling biofilm formation by Candida species resistant to treatment in healthcare settings. Full article

As the global energy industry shifts away from fossil fuels, there is a growing need for sustainable and renewable hydrogen production methods. This research investigates the potential of using biochar derived from animal waste as a precursor for creating effective catalysts for the hydrogen evolution reaction (HER). By incorporating copper and nickel into the biochar through hydrothermal processing, the study examined the resulting catalysts’ structural, chemical, and catalytic properties. Techniques such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR) confirmed the successful integration of metallic nanoparticles and revealed notable changes in surface morphology, elemental composition, and functional group distribution. The Cu–Ni co-doped biochar catalyst (Cu–Ni/BC) demonstrated a significant 45% increase in hydrogen evolution efficiency compared to the undoped biochar control sample. These results highlight the synergistic effects of copper and nickel in enhancing the catalyst’s electron transfer capabilities and active site availability. This study offers a sustainable, cost-effective, and environmentally friendly alternative to conventional hydrogen production catalysts, presenting considerable potential for waste valorization while promoting clean energy solutions. The research aligns with circular economy principles, contributing to the advancement of sustainable energy technologies. Full article

Copper-doped indium zinc sulfides were synthesized by heating and stirring a mixture of zinc chloride, indium chloride tetrahydrate, thioacetamide, and copper chloride at 180 °C for 18 h. Among these, Zn_5.7Cu_0.3In₂S₉ exhibited a hydrogen-producing activity of 1660 μmol/g·h, which was approximately five times higher than that of pristine indium zinc sulfide. Therefore, the catalyst was characterized to investigate the effect of Cu addition. PL results revealed that the incorporation of Cu reduced the fluorescence intensity, indicating suppressed recombination of photogenerated electron–hole pairs. DRS showed that the Cu addition enhanced optical absorption in the visible-light region and narrowed the band gap. These findings suggest that the incorporation of copper into indium zinc sulfide improves its photocatalytic activity. Full article

The efficient electrochemical reduction of carbon dioxide to formate under mild conditions is a promising approach to mitigate the energy crisis, but requires the use of high-performance catalysts. The selectivity and activity of catalysts can be enhanced through multi-metal doping, further advancing the electrochemical reduction of CO₂ to formate. This study demonstrates a co-electrodeposition strategy for synthesizing SnBi electrocatalysts on pretreated copper foam substrates, systematically evaluating how the Sn²⁺/Bi³⁺ molar ratio in the electrodeposition solution and the applied current density affect the catalytic performance for CO₂-to-formate conversion. Optimal performance was achieved with a molar ratio of Sn²⁺ to Bi³⁺ of 1:0.5 and a deposition current density of 3 mA cm⁻², resulting in a formate Faradaic efficiency (FE_formate) of 97.80% at −1.12 V (vs. RHE) and a formate current density of 26.9 mA·cm⁻². Furthermore, the Sn₁Bi_0.50-3 mA·cm⁻² electrode demonstrated stable operation at the specified potential for 9 h, maintaining a FE_formate above 90%. Compared to previously reported metal catalysts, the SnBi catalytic electrode exhibits superior performance for the electrochemical reduction of CO₂ to HCOOH. The study highlights the significant impact of the metal ion molar ratio and deposition current density in the electrodeposition process on the characteristics and catalytic performance of the electrode. Full article

The electrocatalytic decomposition of ammonia represents a promising route for sustainable hydrogen production, yet current systems rely heavily on noble metal catalysts with prohibitive costs and limited durability. A critical challenge lies in developing non-noble electrocatalysts that simultaneously achieve high active site exposure, optimized electronic configurations, and robust structural stability. Addressing these requirements, this study strategically engineered Cu-doped ZIF-8 architectures via in situ growth on nickel foam (NF) substrates through a facile room-temperature hydrothermal synthesis approach. Systematic optimization of the Cu/Zn molar ratio revealed that Cu_0.7Zn_0.3-ZIF/NF achieved optimal performance, exhibiting a distinctive nanoflower-like architecture that substantially increased accessible active sites. The hybrid catalyst demonstrated superior electrocatalytic performance with a current density of 124 mA cm⁻² at 1.6 V vs. RHE and a notably low Tafel slope of 30.94 mV dec⁻¹, outperforming both Zn-ZIF/NF (39.45 mV dec⁻¹) and Cu-ZIF/NF (31.39 mV dec⁻¹). Combined XPS and EDS analyses unveiled a synergistic electronic structure modulation between Zn and Cu, which facilitated charge transfer and enhanced catalytic efficiency. A gas chromatography product analysis identified H₂ and N₂ as the primary gaseous products, confirming the predominant occurrence of the ammonia oxidation reaction (AOR). This study not only presents a noble metal-free electrocatalyst with exceptional efficiency and durability for ammonia decomposition but also demonstrates the significant potential of MOF-derived materials in sustainable hydrogen production technologies. Full article

The report of the first room-temperature, ambient-pressure superconductivity in copper-doped lead apatite Pb_10−xCu_x(PO₄)₆O has attracted lots of attention. However, subsequent studies revealed the presence of numerous impurity phases in the polycrystalline sample, and the sharp superconducting-like transition is not due to a superconducting transition but most likely due to a reduction in resistivity caused by the first-order structural phase transition of Cu₂S at around 385 K from the β phase at high temperature to the γ phase at low temperature. Before now, only bulk measurements have been performed on a Pb_10−xCu_x(PO₄)₆O powder sample, which could be affected by the impurity phases, masking the intrinsic properties of Pb_10−xCu_x(PO₄)₆O. In this study, ³¹P and ^63/65Cu nuclear magnetic resonance (NMR) measurements have been performed on a Pb_10−xCu_x(PO₄)₆O powder sample to investigate its physical properties from a microscopic point of view. Our NMR data evidence the non-magnetic insulating nature of Pb_10−xCu_x(PO₄)₆O without any trace of electron correlation effects. Furthermore, the ^63/65Cu NMR results suggest that no copper or very little copper is substituted for Pb in Pb₁₀(PO₄)₆O prepared by sintering Pb₂SO₅ and Cu₃P. Full article

To enhance the specific energy and rate performance of lithium primary batteries, the development of advanced cathode materials with superior electrochemical properties is essential. Fluorides, composed of light fluorine elements and multivalent cations, exhibit multi-electron reaction characteristics, possess a high theoretical voltage, and demonstrate high discharge-specific energy. However, owing to fluorine’s high electronegativity, which leads to the formation of strong ionic bonds with other elements, most fluorides exhibit poor electronic conductivity, thereby constraining their electrochemical performance when used as cathode materials. Copper fluoride (CuF₂) exhibits a high theoretical specific capacity and discharge voltage but is constrained by its large bandgap, poor electronic conductivity, and difficulties in synthesizing anhydrous CuF₂ materials, which significantly limit its electrochemical activity. In this study, zinc (Zn) was chosen as a dopant for copper fluoride. By combining theoretical calculations with experimental validation, the impacts of Zn doping on the structural stability and electrochemical performance of copper fluoride were comprehensively analyzed. The resultant highly active Zn-doped copper fluoride achieved a discharge specific capacity of 528.6 mAh/g at 0.1 C and 489.1 mAh/g at 1 C, showcasing superior discharge-specific energy and good rate performance. This material holds great potential as a promising cathode candidate for lithium batteries, providing both high specific energy and power density. Full article

The article suggests a simple one-step sol–gel method for synthesizing nanostructured zinc oxide films co-doped with copper and aluminum. It shows the possibility of forming hierarchical ZnO:Al:Cu nanostructures combining branches of different sizes and ranks and quasi-spherical fractal aggregates. It demonstrates the use of the synthesized samples as highly efficient photocatalysts providing the decomposition of toxic dyes (methyl orange) under the action of both ultraviolet radiation and visible light. It establishes the contribution of the average crystallite size, the proportion of zinc atoms in the crystalline phase, their nanostructure, as well as X-ray amorphous phases of copper and aluminum to the efficiency of the photocatalysis process. Full article