Presence Of Cu Ions Research Articles

The Pattern of Copper Release in Copper‐Based Nanoparticles Regulates Tumor Proliferation and Invasiveness in 3D Culture Models

Cancer is a leading cause of death worldwide. Glioblastoma (GBM) is a major challenge in oncology due to its highly invasive nature and limited treatment options. GBM's aggressive migration beyond tumor margins and rapid tumor growth hinders success in patient treatment. Localized therapeutic delivery, such as the use of transition metals like copper, is highlighted as a novel therapeutic agent for many potential biomedical applications. Herein, it is aimed to study the effects of Cu release on the proliferation and invasiveness of cancer cells. To this end, novel copper‐based nanostructures with different release patterns are designed. Using a complex 3D cell culture model to mimic the tumor microenvironment, it is shown that different patterns of copper ion release have a strong impact on GBM progression and invasiveness. The findings highlight the importance of optimizing localized copper release patterns to tailor different tumor treatment strategies. They also show the potential and suitability of 3D microchips as instruments to study the behavior of tumor spheroids. In spite of their limitations, these 3D microdevices enable a controlled and close monitoring of the influence of environmental factors (such as the presence of Cu ions) on the proliferation and invasiveness of the cells, with a better approach to reality compared to 2D models and with a more controlled environment, compared to an in vivo model.

Copper doped hydroxyapatite nanocomposite thin films: synthesis, physico–chemical and biological evaluation

Cu-doped hydroxyapatite (CuHAp) thin films were obtained using spin coating method. To make these thin films, CuHAp suspensions obtained by sol–gel method were used. The coatings obtained were thermally treated at 500 °C. After the thermal treatment, the thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). Moreover, the stability of the suspensions before being used to obtain the thin films was certified by dynamic light scattering (DLS), zeta potential methods and ultrasound measurements. In the XRD patterns, the peaks associated with hexagonal hydroxyapatite were identified in accordance with JCPDS no. 09-0432. EDS and XPS results confirmed the presence of Cu ions in the samples. Data about the morphological features and chemical composition of CuHAp thin films were obtained by performing scanning electron microscopy (SEM) measurements. Our results suggest that the CuHAp thin films surface is continuous and homogenous. The presence of the functional groups in the CuHAp thin films was confirmed by Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy studies. Information about the surface topography of the CuHAp thin films has been obtained using atomic force microscopy (AFM). The AFM images determined that the surface topography of the CuHAp thin layer is homogenous and continuous without presenting any unevenness or fissures. The cytotoxicity of CuHAp thin films was assessed using human gingival fibroblasts (HGF-1) cells. The results of the cell viability assays demonstrated that the thin films presented good biocompatible properties towards the HGF-1 cells. Additionally, the adherence and development of HGF-1 cells on the surface of CuHAp thin films were determined using AFM. The AFM surface topographies highlighted that the CuHAp thin film’s surface favored the attachment and proliferation of HGF-1 cells on their surface.

Synthesis, structural, molecular docking, and in vitro biological activities of Cu-doped ZnO nanomaterials

Copper-doped ZnO nanoparticles with the formula Zn1−x(Cu)O, where x = 0.0, 0.03, 0.05, and 0.07 were produced using the co-precipitation process. Physical, chemical, and structural properties were properly examined. Powdered X-ray diffraction (P-XRD) patterns revealed the formation of hexagonal wurtzite crystal structure in all samples, through atomic substitutional incorporation in the Cu-doped ZnO lattice. The presence of Cu ions and their dissolution in the host ZnO crystal structure was supported by FT-IR spectra. HR-TEM images were used to assess the average size, morphology, and shape regularity of the synthesized samples. The form and homogeneity of the ZnO changed when Cu ions were substituted, as evidenced by FE-SEM/EDX analysis. The presence of copper signals in the Cu-doped samples indicates that the doping was successful. The decrease in zeta potential with an increased copper doping percentage designates that the nanoparticles (NPs) are more stable, which could be attributed to an increase in the ionic strength of the aqueous solution. The synthesized NPs were evaluated for their substantial in vitro antioxidant properties. In addition, the antimicrobial efficacy of the materials was tested against pathogenic microorganisms. Regarding the anti-diabetic activity, the 7Cu ZnO sample showed the highest inhibitory effect on the α-amylase enzyme. No variations were observed in the activities of the acetylcholinesterase enzyme (AChE) and proteinase enzymes with ZnO and samples doped with different concentrations of Cu. Therefore, further studies are recommended to reveal the in-vitro anti-diabetic activity of the studied doped samples. Finally, molecular docking provided valuable insights into the potential binding interactions of Cu-doped ZnO with α-amylase, FabH of E. coli, and Penicillin-binding proteins of S. aureus. These outcomes suggest that the prepared materials may have an inhibitory effect on enzymes and hold promise in the battle against microbial infections and diabetes.

Improvement of the photoelectrical properties of chemical bath-deposited Sb2S3 thin films with low copper doping

The chemical bath deposition method was used to prepare Cu-doped Sb2S3 thin films from complexes of Cu and Sb with triethanolamine. The as-deposited films with orange coloration had good adherence to the substrate. After an annealing treatment at 300 °C for 30 min in an Ar atmosphere, the resulting films acquired a brown color and exhibited the orthorhombic phase of Sb2S3 with the preferential growth of [hk0] grains. The Sb2S3 films were formed by rod-shaped nanoparticles, while the insertion of Cu ions in Sb2S3 promoted the formation of ribbon-like structures. The analysis of optical properties indicated the narrowing of bandgap energy from 1.9 to 1.8 eV due to the presence of Cu ions. In addition, the photoconductivity of the films increased from 8.3 × 10–6 to 30.5 × 10–6 Ω−1cm−1, while the photosensitivity factor was enhanced by more than 3 times. The performance of photovoltaic devices based on CdS/Sb2S3 and CdS/Cu:Sb2S3 heterojunctions were investigated. Compared with the device using a Sb2S3 layer, the one using a Cu-doped Sb2S3 layer exhibited an increase in open circuit voltage from 118.2 to 205 mV, short circuit current density from 0.14 to 0.34 mA/cm2 and conversion efficiency from 0.02 to 0.12%. The best performance was obtained by a photovoltaic device with a 500 nm Cu-doped Sb2S3 layer reaching an open circuit voltage of 226 mV, a short circuit current density of 0.94 mA/cm2 and conversion efficiency of 0.32%.

Copper(II)-Assisted Degradation of Pheophytin a by Reactive Oxygen Species.

The central ion Mg2+ is responsible for the differences between chlorophyll a and its free base in their reactivity toward metal ions and thus their resistance to oxidation. We present here the results of spectroscopic (electronic absorption and emission, circular dichroism, and electron paramagnetic resonance), spectroelectrochemical, and computational (based on density functional theory) investigations into the mechanism of pheophytin, a degradation that occurs in the presence of Cu ions and O2. The processes leading to the formation of the linear form of tetrapyrrole are very complex and involve the weakening of the methine bridge due to an electron withdrawal by Cu(II) and the activation of O2, which provides protection to the free ends of the opening macrocycle. These mechanistic insights are related to the naturally occurring damage to the photosynthetic apparatus of plants growing on metal-contaminated soils.

Tartrate-gel synthesized BaFe12-xCuxO19 (0 ≤ x ≤ 1) nanoceramics: Magnetic and catalytic properties

Magnetic catalysts present distinct advantages over their non-magnetic counterparts, primarily due to their ease of recovery from the reaction mixture through magnetic separation. Herein, magnetic and catalytic properties of Cu-substituted barium hexaferrite (BaFe12-xCuxO19, 0 ≤ x ≤ 1) nanoceramics, synthesized via a tartrate-gel method, are evaluated. Using XRD, FTIR, Raman, SEM, XPS, and VSM techniques, the synthesized compositions were characterized. The powder XRD analysis revealed that all samples predominantly consisted of hexaferrite phase, with small impurity phases, α-Fe2O3, CuO and BaFe2O4. The structural parameters (a, b, c), extracted from Rietveld refinement analysis, increased with ‘x’, primarily due to substitution of smaller Fe3+ cation by larger Cu2+ cation. The FTIR and Raman spectra of the samples exhibited characteristic bands corresponding to the M-type hexaferrite. A red-shift occurred in these bands as the Cu amount increased in the Ba-hexaferrite lattice, owing to increase in metal-oxygen bond length. Due to sintering aid nature of copper, considerable increase in the particle size is observed with inclusion of Cu. XPS spectral analysis indicated the oxygen defects in the Cu-substituted sample. The magnetic parameters (MS, HC, and K1) are found to decrease upon incorporation of Cu ions into the Ba-hexaferrite crystal structure. Conversely, the Curie temperature (TC) showed a slight increase with Cu content ‘x’. The unsubstituted sample (x = 0) exhibited no catalytic activity in the reduction of nitrophenol, whereas both Cu-substituted samples displayed enhanced activity with comparable rate constants (0.02 min−1). This activity was attributed to the presence of Cu ions at the octahedral sites (2a or 4f2). Additionally, a magnetic separation process followed by a reusability test was conducted for the x = 0.5 sample over five successive cycles. The consistent activity observed in each cycle underscored the robustness of the engineered magnetic catalyst.

Additive-free electroless deposition on graphene/copper foil: Photo-induced and defect-assisted approach for environmentally friendly plating

The environmental toxicity of chemicals used in electroless plating process is often overlooked. In fact, the wastewater from the electroless plating process contains metal complexes, reducing agents and stabilizers that can create hazard to our environment. To address this concern, an additive-free electroless deposition process on graphene/Cu foil is proposed. The defect structure of graphene plays a pivotal role by acting as a reservoir for concentrating photoelectrons generated from ultra-thin cuprous oxide (Cu2O) located at the interface of graphene and Cu foil upon exposure to light irradiation. In the Cu ion solution, Cu ions were anchored on the defect sites and formed a Cu-C4 structure with graphene. The Cu-C4 sites accumulate abundant photoelectrons and trigger the reduction of Cu ions to form island-like growth of Cu, which immediately was oxidized to Cu2O, leaving only a small portion of metallic Cu. Concurrently, the presence of Cu ions induces the generation of additional defect sites on graphene, providing further growth sites for Cu deposition. This process continues until the entire graphene surface is covered by the deposited Cu2O. Ultimately, the deposition of metallic oxides with lower redox potential can be achieved. The proposed deposition mechanism assisted by irradiation of photocatalyst and defect structure of graphene material provides a truly environmentally friendly electroless plating process. By eliminating the need for additives and significantly reducing the environmental hazards associated with electroless plating, this method holds great promise for sustainable materials manufacturing.

Vanadium (III) -catechol functionalized copper metal–organic framework for sensitive detection of quercetin in biological fluids

This study describes the preparation of a novel electrocatalyst based on catechol-vanadium charge transfer complex functionalized Copper-benzene 1,3,5- tricarboxylate MOF ((CAT-VIII)-Cu-BTC). The obtained structure is characterized by different analysis methods like XRD, TGA, SEM, EDAX/MAP, and FT-IR. UV–Vis spectrophotometry was applied to investigate the reaction between CAT and vanadate as well as the oxidation state of vanadium. All the analyses confirm the successful functionalizing of Cu-BTC with catechol-vanadium without any change in its crystalline structure. CAT-VIII /Cu-BTC was exploited to modify graphite paste electrode (GPE/CAT-VIII /Cu-BTC) for the detection of quercetin. The results showed that the functionalization of Cu-BTC with catechol-vanadium (III) causes increased electrocatalytic activity not only due to the presence of Cu ions but also due to the presence of vanadium ions. GPE/ (CAT-VIII)-Cu-BTC presents outstanding features toward electrooxidation of quercetin to a well-defined anodic peak at 0.5 V. The proposed sensor is introduced as a suitable alternative for quantitate sensing of QR in biological fluids.

The Impact of Copper Ions on the Activity of Antibiotic Drugs.

Copper (Cu) is an essential trace metal and its concentration in body plasma is tightly regulated. An increase in Cu concentration in body fluids is observed in numerous pathological conditions, including infections caused by microorganisms. Evidence shows that Cu ions can impact the activity of antibiotics by increasing efficiency or diminishing/neutralizing antibiotic activity, forming complexes which may lead to antibiotic structure degradation. Herein, we represent the evidence available on Cu-antibiotic interactions and their possible impact on antimicrobial therapy efficiency. So far, in vitro studies described interactions between Cu ions and the majority of antibiotics in clinical use: penicillins, cephalosporins, carbapenems, macrolides, aminoglycosides, tetracyclines, fluoroquinolones, isoniazid, metronidazole. In vitro-described degradation or lower antimicrobial activity of amoxicillin, ampicillin, cefaclor, ceftriaxone, and meropenem in the presence of Cu ions suggest caution when using prescribed antibiotics in patients with altered Cu levels. On the other hand, several Cu-dependent compounds with antibacterial activity including the drug-resistant bacteria were discovered, such as thiosemicarbazones, disulfiram, dithiocarbamates, 8-hydroxiquinoline, phenanthrolines, pyrithione. Having in mind that the development of new antibiotics is already marked as inadequate and does not meet global needs, the potential of Cu-antibiotic interactions to change the efficiency of antimicrobial therapy requires further investigation.

Evaluation of copper-induced biomolecular changes in different porin mutants of Escherichia coli W3110 by infrared spectroscopy.

Copper (Cu), one of the heavy metals, plays a vital role in many complex biochemical reactions as a trace element. However, it often becomes toxic when its concentration in the cell exceeds a certain level. Homeostasis of metals in the cell is primarily related to regulating metal transport into and out of the cell. Therefore, it is thought that porin proteins, which have a role in membrane permeability, may also play a role in developing Cu resistance. This study identified the differences between the molecular profiles of wild-type Escherichia coli W3110 and its seven different porin mutants exposed to Cu ions using attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy. The results showed that the absence of porin genes elicits global changes in the structure and composition of membrane lipids and proteins, in both the absence and presence of Cu. The lack of porin genes significantly elevated the amounts of fatty acids and phospholipids. When the alterations in protein secondary structures were compared, the quantity of amide I proteins was diminished by the presence of Cu. However, the amount of amide II proteins increased in porin mutant groups independent of Cu presence or absence. The DNAs are transformed from B- and Z-form to A-form due to porin mutations and the presence of Cu ions. The lack of porin genes increased polysaccharide content independent of Cu presence. This study can help characterize Cu detoxification efficiency and guide for obtaining active living cells to be used in bioremediation.

Flame-retardant and antibacterial properties of cotton fabrics treated by epichlorohydrin-modified aramid nanofibers, ionic liquid, and Cu ion

To meet the demands of reducing the serious illness caused by the growth of bacteria and the severe life-threatening due to interior fabric fire, the attention to antibacterial flame-retardant cotton fabrics has reached an unprecedented height. In this work, a simple step-by-step dip-coating method was applied for the multifunctional cotton based on epichlorohydrin-modified aramid nanofibers (AEP), ionic liquid (IL), and CuSO4. Cot/AEP/IL/Cu exhibited low flammability with a limiting oxygen index (LOI) improving from 18.5% to 28.5% and high flame retardancy (e.g., ∼43.7% and 41.7% decline in peak heat release rate (pHRR) and total heat release rate (THR)). Noticeably, the Cot/AEP/IL/Cu revealed conspicuous smoke suppression and toxic reduction property compared with Cot/AEP/IL (e.g., ∼77.0% decline in peak smoke release rate (pSPR) and 40.5% in total CO production (TCOP)). In addition, the antibacterial property of treated cotton was investigated by the agar diffusion plate method. Due to the presence of Cu ion, Cot/AEP/IL/Cu remarkably restrains the activity of E. coli and S. aureus. This work prepared a multifunctional cotton fabric integrated with flame-retardant, smoke suppression, toxicity reduction, and antibacterial in a straightforward way, which endows promising applications in many fields.

Cu(II) ions removal from wastewater using starch nanoparticles (SNPs): An eco‐sustainable approach

AbstractThe complex structured starch particles were reduced to the nanoscale size range through hydrolysis utilizing low concentration acid assisted by ultrasound irradiation. The synthesized starch nanoparticles (SNPs) were characterized by transmission electron microscopy (TEM), Fourier‐transform infrared (FTIR), and X‐ray diffraction (XRD) techniques. The synthesized SNPs possessed surface activated entities, as many cationic functional groups were confirmed through the FTIR spectrum. Also, these SNPs were effectively utilized to separate heavy Cu metal ions from the synthetic ion solution. The SNPs were characterized using field emission scanning electron microscope (FESEM), X‐ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) analysis for the surface modification after the adsorption process. The weak electrostatic interaction between the SNP surface and Cu ion was confirmed by the XPS spectrum and energy‐dispersive X‐ray spectroscopy. The maximum efficiency of Cu ions removal was about 93% at an optimal pH 5 and 25 mg/ml dosage. The adsorption equilibrium was obtained in 60 min. The nitrogen isotherm BET analysis of SNPs after adsorption shows a higher specific surface area of 18.552 m2/g, attributed to the interaction and presence of Cu ions on the SNP surface. The process feasibility was validated by the Langmuir isotherm model. The process exhibits pseudo‐second‐order adsorption kinetics and follows the Langmuir isotherm. The RL predicted by the Langmuir isotherm mechanism is 0.017, implying favourable adsorption. The process is reproducible and allows for the separation of heavy metal ions from the wastewater through biosorption effectively.

The Preliminary Studies on the Tremendous Degradation Rate of Methylene Blue with Cu-doped α-MnO2 Photocatalyst Under UV Light Irradation

Dye contaminations have severe impacts to environment (air, soils, plants, water) due to their adverse effects. Most dyes are toxic, carcinogenic, mutagenic and resistant to bio-degradation. Photocatalysis-based advanced oxidation process (AOP) has been considered as the most effective and efficient way to treat this recalcitrant compounds. Manganese oxides are ubiquitous and environmentally friendly in natural environments and can act as semiconducting materials. Tunnel structure of manganese oxide such as α-MnO2 (cryptomelane) has been widely studied for broad applications as Fenton-based AOP. Catalytic efficiency of α-MnO2 could be further increased by doping α-MnO2 with a metal ion like the Cu ion. Although the synthesis and catalytic activity of Cu-α-MnO2 have been reported by previous studies, its photocatalytic performance using this one-pot-sol-gel approach for MB degradation has never been reported previously. Herein, Cu-doped α-MnO2 was synthesized by one-pot sol-gel method and characterized by X-ray diffraction (XRD), BET surface area and atomic absorption spectroscopy (AAS). The AAS results suggested the presence of Cu ions in α-MnO2 since the increase in doping Cu resulted in the corresponding increase in Cu content in the α-MnO2. The BET surface area indicated that the doping 10% Cu in α-MnO2 led to about two fold increase in suface area compared to undoped α-MnO2. The photo catalytic performance of Cu-α-MnO2 via UV light irradiation for the degradation of methylene blue (MB) was significantly higher that that of undoped α-MnO2 and was associated with the increased in surface area of Cu-α-MnO2 over undoped α-MnO2. The maximum degradation of MB was 97.9, 98.3, 98.7 and 99.5% achieved using α-MnO2, 1% Cu-α-MnO2, 5% Cu-α-MnO2, and 10% Cu-α MnO2 and 10% Cu-α-MnO2.

Biosorption of copper from aqueous environment by three aquatics-based sorbents: A comparison of the relative effect of seven important parameters

This study aimed to investigate the removal potential of copper from aqueous solutions using three aquatic origin biosorbents (scales of two fish species and shells of a mollusk), for the first time. A Box–Behnken design was used to investigate the effects of the seven important variables on the sorption capacities. The effects of initial concentration, pH and dosage, on all the response variables were significant. pH and initial concentration were the most influential factors. The order of maximum adsorption capacities of the biosorbents was: shells of Cerastoderma glaucum < scales of Rutilus kutum and < scales of Oncorhynchus mykiss. The characterization analyses showed the presence of Cu ions on the surfaces of all the biosorbents after the experiments. The equilibrium data of the Cu adsorption by R. kutum scales, O. mykiss scales and C. glaucum shells were best described by Langmuir, Temkin and Freundlich isotherm models, respectively.

Synthesis of Cu doped cobalt oxide nanoparticles as ammonia gas sensor operating at room temperature

In this work, hydrothermally synthesized copper doped cobalt oxide nanoparticles were utilized for the detection of ammonia gas. The powder samples were described by different characterization techniques. XRD spectrum revealed the crystalline structure of the sample. The morphology and component analysis of nanoparticles was done by SEM and EDAX respectively. The FTIR investigation affirmed the presence of functional group in the sample. Optical properties were assessed by UV–Vis spectroscopy. The optical properties were evaluated by UV–Vis spectroscopy. Doping is an effective way to increase gas sensitivity. The sensing properties of cobalt oxide nanoparticles has been enhanced due to the utilization of Cu as a dopant. In the present work, we put emphasis on a cost effective method to achieve supreme sensitivity towards NH 3 gas at room temperature even at a lower concentration of 5 ppm. The presence of Cu ions on the surface of Co 3 O 4 nanoparticles was found to enhance the sensor performance.

An investigation of morphological, microscopic dynamics, fluidity, and physicochemical variations in Cu-decorated metallosomes with cholesterol

The controlled stoichiometry of single-tailed surfactant cetylpyridinium chloride (CPC) in the presence of Cu ions led to a vesicular assembly known as ‘metallosomes’. Unlike liposomes, their membrane properties such as microscopic dynamics, fluidity, and physicochemical variations, have not been explored. Therefore, metallosomes with a water-soluble metallosurfactant (bishexadecylpyridiniumcopper tetrachloride) with varying cholesterol concentrations were synthesized and explored for the induced effect of cholesterol on different membrane properties. Three different metallosomes were synthesized by varying the metallosurfactant to cholesterol molar ratio to 1:0, 1:0.5, and 1:1 and characterized with cryo-TEM, FESEM, DLS, and ζ-potential. For microscopic dynamics studies, quasielastic neutron scattering (QENS), for bilayer molecular arrangement XRD and SAXS, and for physicochemical properties, three fluorescent probes (ANS, Prodan, and Laurdan) were utilized. The Well Diffusion method was employed for exploring the antimicrobial behavior of empty as well as drug-loaded metallosomes. The spherical morphology of synthesized metallosomes was established with different studies and insertion of cholesterol has been found to lead to more stable and homogeneous suspensions. Also, more restricted, less fluid, and dehydration of membrane was observed with cholesterol. The antimicrobial activity as well as releasing profile was observed to be directly influenced in the presence of cholesterol.

Optical parameters, antibacterial characteristics and structure correlation of copper ions in cadmium borate glasses

Binary base borate glass of nominal composition (45CdO.55B2O3 mol%) and other samples containing up to 1.6 mol% CuO were successfully prepared using melt annealing route. Fourier transforms infrared (FTIR) spectra of the prepared glasses were studied to identify the structural building groups within the glasses and the role of Cu ions in the matrix arrangement.UV spectra of studied glasses reveal two intense narrow bands originally located at about 235 and 310 nm attributed for the presence of trace iron impurities present on the chemical used for preparation even in the ppm level. Additional analyzed broad visible band centered at about 780 nm appears in the spectra of CuO doped glasses and exhibit splitting at high CuO content. Optical energy gap and other physical parameters including refractive index, density, molar volume, molar refraction, electronic polarizability, and optical basicity reveal strong correlation with copper ion speciation.Both experimental and deconvoluted FTIR spectra of the studied glasses reveal characteristic absorption bands indicating the presence of both triangular and tetrahedral borate groups in their separate vibrational sites. The presence of Cu ions within the doping level is observed to cause no changes in the main characteristic IR bands but limited changes in the intensity of some bands and loosing of the splitting are observed.Antibacterial studies disclose diverse inhibition zone associated with an increase of CuO content and type of bacteria under examination connected with their activity index percent.

Triazoles and aromatase: The impact of copper cocktails

Triazoles are used as antifungal agents, they mostly inhibit two enzymes: 14α-demethylase and aromatase. These enzymes are utilised also in other species and therefore the affection in non-target species in the environment is expected as well. Besides, triazoles are often being applied in a mixture and they can also interact with other substances present. This study clarifies how three selected representative triazoles (tebuconazole, penconazole and cyproconazole) interact with each other (group effect) and in mixtures (cocktail effect) with copper, essential/toxic for all organisms. Within the experiments on electrospray and collision-induced dissociations (both ESI-MS), it has been found that the fragments correspond to typical triazole metabolites. For their formation, the presence of copper ions is crucial. The inhibitory effect of Cu cocktails on aromatase enzymatic activity has been studied. The presence of Cu ions together with triazole(s) significantly increases the inhibitory effect on aromatase activity. The highest inhibitory effect (more than 60%) on aromatase activity is produced by cocktails containing penconazole and Cu ions, namely by penconazole/Cu and penconazole/tebuconazole/Cu. The reactivity of triazoles in groups is not significantly affected by the interactions among them. Additionally, the role of triazoles in copper Fenton reaction regulation has been observed and described. These changes may be attributed to the formation and stabilization of the complexes with the central Cu ion, with usually one, two or three triazolic ligands, depending on the mixture. The study demonstrates that the interaction of triazoles and Cu ions is a complex process; their impact on metabolism seems to be rather extensive and must be evaluated in the context of biochemical reactions.

In Situ DRIFTS Investigation of Ethylene Oxidation on Ag and Ag/Cu on Reduced Graphene Oxide

Reduced graphene oxide (rGO) was synthesized and impregnated with silver and silver/copper for in situ DRIFTS investigation of ethylene oxidation. The catalysts were characterized using different techniques. SEM micrographs showed that the metals are dispersed on the rGO surface. XPS results showed the presence of the metallic silver and copper as CuO and Cu2O oxides. The in situ DRIFTS showed that in both catalysts the total oxidation of ethylene reaction prevails besides the intermediate formation of acetaldehyde. The presence of Cu ions or CuO and Cu2O at the surface indicate the presence of electronic structure, which may enhance the oxidation reaction.

Bistable mirror/transparent reversibly electrodeposited devices with TiO2 as the mediator

Reversible electrodeposition (RED) devices exhibit both transparent and mirror states, allowing light penetration and reflection. Therefore, the incident light transmission regulates the radiant heat generation. However, the low bistability of these devices is the main limitation to their application in windows since it causes continue energy consumption to maintain the mirror state; this is mainly due to the presence of Cu ions in the electrolyte, which is the main dissolution agent of the deposited Ag metal. Thus, we used a three-layered TiO2 counter electrode as an electrochemical reaction mediator and eliminated the Cu ions. In addition, the Ag thin film pre-deposited on the working electrode effectively enhanced the bistability. The combination of three-layered TiO2 and the pre-deposited Ag film allowed a reflectance of 78% and enhanced the mirror-state maintenance of the mirror state. After switching off the voltage, the retained reflectance was 17% at three-layered TiO2 more than twice larger than that at one-layered TiO2 (7%). The bistability and reflectance increase in the proposed RED devices with respect to those based on a Cu-containing electrolyte.