Divalent Copper Ions Research Articles

Target-Induced On-Protein Clustering of Metal Peptide Enables Low Overpotential Water Splitting for Early Detection of Non-Small-Cell Lung Cancer.

This study presents a novel method for the early detection of non-small-cell lung cancer (NSCLC) by employing target-induced on-protein clustering of metal-peptide complexes to facilitate low overpotential water splitting. The approach utilizes a designed peptide molecular probe composed of an EGFR-targeting motif and a copper-chelating tetrapeptide. Upon interaction with the epidermal growth factor receptor (EGFR) and divalent copper ions, the peptide probe forms a stable complex that undergoes on-protein clustering. This clustering significantly amplifies the electrochemical signal through enhanced dityrosine cross-linking and subsequent water splitting, achieving low overpotential for detection. The method was validated using clinical tissue samples and demonstrated improved sensitivity and specificity compared with traditional detection methods. This technique holds promise for earlier and more accurate diagnosis of NSCLC, leveraging the unique properties of metal-peptide interactions and electrochemical signal amplification.

Positively charged residues play a significant role in enhancing the antibacterial activity of calcitermin

A systematic study on the human antimicrobial peptide calcitermin (VAIALKAAHYHTHKE) and its carefully designed derivatives was undertaken to verify the impact of divalent copper and zinc ions on the stability, coordination and antimicrobial activity of the formed complexes. In this work we investigate the calcitermin mutants where the alanine in position 7 and 8 is substituted with an arginine residue, with the aim of enhancing the antibacterial activity. Additionally, the analogue where alanine in position 7 is replaced with a histidine is considered, to obtain a chelating sequence with four histidines in alternate position; the aim of this change was to increase the cationic properties of the peptide under acidic conditions and possibly enhance its binding ability towards the metal ions. Through a comprehensive analytical approach involving potentiometric titrations, mass spectrometry, UV–Vis spectrophotometry, NMR and circular dichroism, we delved into the formation equilibria and coordination chemistry of the formed copper(II) and zinc(II) complexes. Antimicrobial assays are also performed to assess the bioactivity of the compounds against a broad spectrum of microorganisms, revealing the pivotal role of positively charged residues in enhancing the antibacterial activity of calcitermin. The obtained results serve as an important stepping stone towards the development of novel metal-based antimicrobial agents.

Synthesis and Characterization of Copper-Crosslinked Carbon Dot Nanoassemblies for Efficient Macrophage Manipulation.

Nanomedicines loaded in macrophages (MAs) can actively target tumors without dominantly relying on the enhanced permeability and retention (EPR) effect, making them effective for treating EPR-deficient malignancies. Herein, copper-crosslinked carbon dot clusters (CDCs) are synthesized with both photodynamic and chemodynamic functions to manipulate MAs, aiming to direct the MA-mediated tumor targeting. First, green fluorescent CDs (g-CDs) are prepared by a one-step hydrothermal method. Subsequently, the g-CDs are complexed with divalent copper ions to form copper-crosslinked CDCs (g-CDCs/Cu), which are incubated with MAs for their manipulation. Experimental results revealed that the prepared g-CDCs/Cu displayed good aqueous dispersibility and fluorescent emission properties. The nanoassemblies can be activated to deplete the overexpressed glutathione (GSH) and generate reactive oxygen species (ROS) in the presence of laser irradiation through the combined Cu-mediated chemodynamic therapy and CD-mediated photodynamic therapy. Furthermore, the ROS produced in MAs enabled polarization of MAs to antitumor M1 phenotype, suggesting the future potential use to reverse the immunosuppressive tumor microenvironment. These results obtained from the current study suggest a significant potential to develop g-CDCs/Cu for GSH depletion, ROS generation, and MA M1 polarization as a theransotic agent to tackle cancer.

Regulating the zinc ion transport kinetics of Mn3O4 through copper doping towards high-capacity aqueous Zn-ion battery

High working voltage, large theoretical capacity and cheapness render Mn3O4 promising cathode candidate for aqueous zinc ion batteries (AZIBs). Unfortunately, poor electrochemical activity and bad structural stability lead to low capacity and unsatisfactory cycling performance. Herein, Mn3O4 material was fabricated through a facile precipitation reaction and divalent copper ions were introduced into the crystal framework, and ultra-small Cu-doped Mn3O4 nanocrystalline cathode materials with mixed valence states of Mn2+, Mn3+ and Mn4+ were obtained via post-calcination. The presence of Cu acts as structural stabilizer by partial substitution of Mn, as well as enhance the conductivity and reactivity of Mn3O4. Significantly, based on electrochemical investigations and ex-situ XPS characterization, a synergistic effect between copper and manganese was revealed in the Cu-doped Mn3O4, in which divalent Cu2+ can catalyze the transformation of Mn3+ and Mn4+ to divalent Mn2+, accompanied by the translation of Cu2+ to Cu0 and Cu+. Benefitting from the above advantages, the Mn3O4 cathode doped with moderate copper (abbreviated as CMO-2) delivers large discharge capacity of 352.9 mAh g−1 at 100 mA g−1, which is significantly better than Mn3O4 (only 247.8 mAh g−1). In addition, CMO-2 holds 203.3 mAh g−1 discharge capacity after 1000 cycles at 1 A g−1 with 98.6 % retention, and after 1000 cycles at 5 A g−1, it still performs decent discharge capacity of 104.2 mAh g−1. This work provides new ideas and approaches for constructing manganese-based AZIBs with long lifespan and high capacity.

Jahn-Teller effect and features of divalent copper ion behavior in multicomponent borate crystals

Crystals of YGa3(BO3)4, YAl3(BO3)4, EuGa3(BO3)4 and EuAl3(BO3)4 with copper alloy were studied by electron paramagnetic resonance and X-ray diffraction analysis. The lattice parameters and coordinates of copper-doped boron atoms were determined. The study of EPR spectra showed that copper is in the divalent state and replaces aluminum ions with C2 node symmetry. In YAl3(BO3)4:Cu crystals, a ligand structure exists due to the interaction of copper electrons with yttrium nuclei. The parameters of the spin Hamiltonian describing the behavior of the Cu2+ spectrum have been determined. The deviation of the Z-axis spectra from the C3 axis by 54(1)° is due to Jahn-Teller vibronic interaction and monoclinic distortion. In the EuGa3(BO3)4 crystal, a new spectrum 2 was found, which also belongs to divalent copper but is observed at an excited state 31 cm−1 away from the ground state. Above 70 K, an isotropic EPR line with a width of 450 Gs, g = 2.1, appears and exists up to room temperature.

Construct functional PEGDA/CSMA/CuII photosensitive ink for SLA 3D printing of blood contact appliance

Stereolithography (SLA) is an emerging technology in three-dimensional printing that has garnered significant attention in the biomedical field due to its high printing fidelity, good biocompatibility, and high spatial resolution. Polyethylene glycol diacrylate (PEGDA) is commonly used as a photosensitive printing ink in SLA, and it possesses excellent biocompatibility, photosensitivity, processability, water solubility, and biomechanical tunability. Additionally, PEGDA exhibits unique anti-protein, platelet, and cell adhesion possibilities, making it a promising material for blood contact applications. However, cross-linking PEGDA using chain growth photopolymerization results in a high concentration of reactive functional groups, leading to high print volume shrinkage, decreased precision of the finished product, warping, deformation, and cracking. This study introduces a chemically modified methacryloylated chitosan (CSMA) as a cross-linking agent into the PEGDA ink. This strategy effectively reduces the volume shrinkage of the ink and imparts antimicrobial properties to the final product. The dual anticoagulation properties of PEGDA were achieved by loading divalent copper ion (CuII) into the ink, which better addresses the antimicrobial and anticoagulant needs in the physiological environment of blood. The results show that SLA printable inks based on PEGDA/CSMA/CuII have low swelling, high print fidelity, high stability, and good cell compatibility. Furthermore, by verifying the functionality of PEGDA/CSMA/CuII, the research shows that the bioprinting ink exhibits excellent antibacterial and anticoagulant properties, making it a promising material candidate for SLA 3D printing of blood purification, central venous catheter, and other semi-implanted blood materials. This study provides new ideas for developing multifunctional photosensitive inks in biomedical engineering.

Снижение биокоррозии деталей оборудования, эксплуатируемого в подземных выработках за счет применения детонационного Ti-Cu напыления

Introduction. The wide distribution of microorganisms in the natural and technogenic environment, in the conditions of underground mine workings, is explained by their phenomenal adaptation capabilities. The high activity of microorganisms at significant depths under extreme conditions is due to the peculiarities of their metabolism. The maximum number of these factors is typical for underground mining. The lithosphere, in which underground structures are built to ensure the development of deposits, in addition to its well-known characteristics, is also a habitat for microorganisms. The waste products of these microorganisms significantly influence the rate of corrosion of metals. Often the scale and speed of bio damage are so significant. Therefore, the study of microbial bio damage processes and their prevention under these conditions is an extremely urgent task. Materials and methods. The corrosion rate in an aggressive biological environment of three types of samples was studied. The first type of samples were ordinary plates made of St 3. The second type of samples was the same St 3 but with antimicrobial enamel XC-5286 applied to the surface. And the third type of samples were samples made of St 3 with a detonation coating applied to their surface from a mixture of Ti (PTN-8VT10) and Cu (PMS-1) powders. These samples were exposed to a biologically active corrosive environment for one month. Then the level of damage and corrosion development on the surface of the samples was measured. Results. The results of the study showed that the use of the method of detonation thermal spraying makes it possible to form a protective Ti-Cu composite coating with anti-corrosion properties on the surface of low-carbon steel. The rate of biological corrosion of steel samples with Ti-Cu coating is 40% less than on control samples without such a coating. The anti-corrosion efficiency of the XC-5286 coating was 80%. Discussion. The antimicrobial effectiveness of Cu ions primarily depends on their concentration adjacent to the coating surface, which in turn is determined by the rate of release of biocide ions. When immersed in an aqueous solution, copper (I) oxide (Cu2O), which is part of both the XC-5286 coating and the Ti-Cu composite coating formed by thermal spraying, is unstable and, under the influence of chlorine, hydrogen and oxygen ions, quickly oxidizes to more stable divalent copper ions Cu2+. To maintain the required level of antimicrobial effect, the average rate of release of copper ions from contact-type coatings (which includes XC-5286) must be at least 50 μg/cm2 day. The rate of release of Cu ions from a composite Cu-Ti coating formed by plasma spraying is about 20.5 μg/cm2 day, which is almost 2 times less than the required level. This explains the lower antimicrobial efficiency (AE) of Ti-Cu composite coatings compared to XC-5286 enamel, which has an AE value of 80.5%. As shown by full-scale tests, even at low values of the release rate of Cu ions, the coating under study provides effective inhibition of the development of bio corrosion. Conclusions. The work established that the use of the method of detonation thermal spraying made it possible to form a protective Ti-Cu composite coating with anti-corrosion properties on the surface of low-carbon steel. Resume. The work established that the use of the method of detonation thermal spraying made it possible to form a protective Ti-Cu composite coating with anti-corrosion properties on the surface of low-carbon steel. Such Ti-Cu-based coatings can be used not only to protect mechanisms, structural elements and structures operating in mining conditions, but also for their operation in humid climates subject to periodic wetness.

A pH-responsive injectable hydrogel for enhanced chemo-chemodynamic synergistic therapy

Cisplatin (cis-diammine-dichloro-platinum II, CDDP) is one of the most commonly used chemotherapeutic agents for the treatment of esophageal cancer, and its clinical application has been greatly limited due to non-specific administration, severe systemic toxicity, and reduced efficacy due to drug resistance. The special physicochemical properties of hydrogels enable them to achieve a sustained controlled release of CDDP and to maintain high local drug concentrations over a long period, but the problem of drug resistance still needs to be addressed. Herein, CS-BA-PVA, a pH-responsive hydrogel is used to co-load CDDP and divalent copper ion (Cu2+) for constructing a drug delivery system CS-BA-PVA@Cu/CDDP to achieve controlled and sustained drug release. Once reaching the acidic tumor microenvironment (TME), CS-BA-PVA@Cu/CDDP specifically responds and disassembles to release CDDP for chemotherapy against cancer. Besides, the simultaneous release of Cu2+ can deplete the intracellular glutathione (GSH) for increased toxicity of CDDP as well as catalyzing the decomposition of intra-tumoral H2O2 into highly toxic •OH for chemodynamic therapy (CDT). Moreover, the substantially reduced GSH can also protect the yielded •OH from scavenging and thus greatly improve the •OH-based CDT effect. In addition to providing a new drug delivery system CS-BA-PVA@Cu/CDDP, this study is also expected to establish a new form of TME-responsive carrier for highly efficient tumor-specific GSH-depletion-enhanced synergistic chemotherapy/chemodynamic therapy.

Structural, optical, and shielding characteristics of CuO diborate glasses containing lithium fluoride or lithium oxide

A glass system of the basic composition xLiF-(25-x) Li2O-74.8B2O3 containing 0.2 CuO mol% dopant (x = 0, 5, 10, 15, 20, 25) was successfully prepared via the traditional melt quenching method. The sample was coded as 0LiF, 5LiF. 10LiF, 15LiF, 20LiF, 25LiF respectively. Combined optical, and Fourier transform infrared spectral measurements together with radiation shielding parameters were carried out. The amorphous nature of the present glasses was confirmed by utilizing X-ray diffraction patterns. UV/Visible electronic spectra of the studied sample disclose a strong UV absorption glass network. Copper-doped glasses display greenish-blue colors in combination with very broad visible bands pointing to a different overlapping peak. This extended characteristic band is related to absorption due to divalent copper (Cu2+) ions in distorted octahedral coordination. The FTIR data of the CuO-doped glasses reveal extended vibrational modes due to the presence of both triangular and tetrahedral borate glasses in their varying distinct wavenumbers. The Phys-PSD software has been used to compute shielding parameters including mass attenuation coefficient, tenth value layer, effective atomic number, mean free path, and build-up factors in the energy range of 0.015 to 15 MeV. Based on the obtained results, the investigated glasses have good features that make them very suitable for optical and shielding applications. Studied samples proposed to be used in optical devices as LiF appears to control optical parameters.

Further Limitations of Synthetic Fungicide Use and Expansion of Organic Agriculture in Europe Will Increase the Environmental and Health Risks of Chemical Crop Protection Caused by Copper-Containing Fungicides.

Copper-containing fungicides have been used in agriculture since 1885. The divalent copper ion is a nonbiodegradable multisite inhibitor that has a strictly protective, nonsystemic effect on plants. Copper-containing plant protection products currently approved in Germany contain copper oxychloride, copper hydroxide, and tribasic copper sulfate. Copper is primarily used to control oomycete pathogens in grapevine, hop, potato, and fungal diseases in fruit production. In the environment, copper is highly persistent and toxic to nontarget organisms. The latter applies for terrestric and aquatic organisms such as earthworms, insects, birds, fish, Daphnia, and algae. Hence, copper fungicides are currently classified in the European Union as candidates for substitution. Pertinently, copper also exhibits significant mammalian toxicity (median lethal dose oral = 300-2500 mg/kg body wt in rats). To date, organic production still profoundly relies on the use of copper fungicides. Attempts to reduce doses of copper applications and the search for copper substitutes have not been successful. Copper compounds compared with modern synthetic fungicides with similar areas of use display significantly higher risks for honey bees (3- to 20-fold), beneficial insects (6- to 2000-fold), birds (2- to 13-fold), and mammals (up to 17-fold). These data contradict current views that crop protection in organic farming is associated with lower environmental or health risks. Further limitations in the range and use of modern single-site fungicides may force conventional production to fill the gaps with copper fungicides to counteract fungicide resistance. In contrast to the European Union Green Deal goals, the intended expansion of organic farming in Europe would further enhance the use of copper fungicides and hence increase the overall risks of chemical crop protection in Europe. Environ Toxicol Chem 2024;43:19-30. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Multi-functionalization of cotton fabrics with excellent flame retardant, antibacterial and superhydrophobic properties

Cotton fabric is widely used in many fields for its excellent comfortability, breathability and hygroscopicity. However, the development of multifunctional cotton fabrics to meet the requirements of different scenarios is a top priority. In this study, multifunctional coating was constructed through facile layer-by-layer assembly phytic acid and chitosan, and spraying divalent copper ion and polydimethylsiloxane (PDMS) on cotton fabrics, anticipating to endow them with flame retardancy, antibacterial and superhydrophobic properties simultaneously. The treated cotton fabric achieved a limiting oxygen index (LOI) value of 32 %, with the char length reducing to 10.7 cm revealing excellent flame retardancy. The water contact angle of multifunctional treated cotton fabric was above 150°, demonstrating it had superhydrophobicity. The antibacterial rates of multifunctional cotton fabrics against E. coli and S. aureus reached to higher than 99 %, indicating that the excellent antibacterial properties. Combined with the thermal stability of cotton fabrics and their char residues analysis, these results demonstrated that the multifunctional coating could act through intumescent flame retardant mechanism to flame retardant cotton fabrics. This research provides a facile way to prepare multifunctional cotton fabrics to broaden the application prospect.

Calculation and study for the growth process and electrical characteristics of the conductive filament in nanoscale resistance memory under current-driven mode

After investigating the behavior of ions during the growth of conductive filaments, we suggested a model for the growth process and electrical characteristics of the conductive filament under current-driven mode. In this model, the ionic displacement equation is derived by Arrhenius law, and a differential equation for the conductive filament growth has been established. We have also proved that the dielectric layer with the leakage current under current-driven mode can be equivalent to a parallel plate capacitor, which has a the equivalent dielectric constant. Consequently, the forming/set time of the device is gotten. At the same time, the kinetics process of ion motion is analyzed in detail, so that many microscopic parameters of the ion motion, such as the height of the potential barrier, the jump step, mobility and diffusion coefficient, can be obtained. Due to divalent and monovalent copper ions all participate in conduction, an equivalent copper ion Cuz+ is used for replacing both Cu+ and Cu2+, solving the computational complexity problem caused by multivalent metal ions. Finally, an equivalent circuit is proposed to calculate output voltage versus time characteristic. The calculation results of the model are consistent with experimental data.

Double- or Triple-Tiered Protection: Prospects for the Sustainable Application of Copper-Based Antimicrobial Compounds for Another Fourteen Decades

Copper (Cu)-based antimicrobial compounds (CBACs) have been widely used to control phytopathogens for nearly fourteen decades. Since the first commercialized Bordeaux mixture was introduced, CBACs have been gradually developed from highly to slightly soluble reagents and from inorganic to synthetic organic, with nanomaterials being a recent development. Traditionally, slightly soluble CBACs form a physical film on the surface of plant tissues, separating the micro-organisms from the host, then release divalent or monovalent copper ions (Cu2+ or Cu+) to construct a secondary layer of protection which inhibits the growth of pathogens. Recent progress has demonstrated that the release of a low concentration of Cu2+ may elicit immune responses in plants. This supports a triple-tiered protection role of CBACs: break contact, inhibit microorganisms, and stimulate host immunity. This spatial defense system, which is integrated both inside and outside the plant cell, provides long-lasting and broad-spectrum protection, even against emergent copper-resistant strains. Here, we review recent findings and highlight the perspectives underlying mitigation strategies for the sustainable utilization of CBACs.

Thiol-Surface-Engineered Cellulose Nanocrystals in Favor of Copper Ion Uptake.

Cellulose, the most abundant natural polymer on earth, has recently gained attention for a large spectrum of applications. At a nanoscale, nanocelluloses (mainly involving cellulose nanocrystals or cellulose nanofibrils) possess many predominant features, such as highly thermal and mechanical stability, renewability, biodegradability and non-toxicity. More importantly, the surface modification of such nanocelluloses can be efficiently obtained based on the native surface hydroxyl groups, acting as metal ions chelators. Taking into account this fact, in the present work, the sequential process involving chemical hydrolysis of cellulose and autocatalytic esterification using thioglycolic acid was performed to obtain thiol-functionalized cellulose nanocrystals. The change in chemical compositions was attributed to thiol-functionalized groups and explored via the degree of substitution using a back titration method, X-ray powder diffraction, Fourier-transform infrared spectroscopy and thermogravimetric analysis. Cellulose nanocrystals were spherical in shape and ca. 50 nm in diameter as observed via transmission electron microscopy. The adsorption behavior of such a nanomaterial toward divalent copper ions from an aqueous solution was also assessed via isotherm and kinetic studies, elucidating a chemisorption mechanism (ion exchange, metal chelation and electrostatic force) and processing its operational parameters. In contrast to an inactive configure of unmodified cellulose, the maximum adsorption capacity of thiol-functionalized cellulose nanocrystals toward divalent copper ions from an aqueous solution was 4.244 mg g-1 at a pH of 5 and at room temperature.

Copper ions and the R peptides of tau: structural and functional study

AbstractBackgroundOne of the common neurodegenerative disorders is the aggregation of Tau protein plays a major role in Alzheimer’s disease. Transmission metals ions such as Cu, Zn, and Fe are vital ingredients that must maintain homeostasis in the biological system. Tau Protein has four repeat peptide units (R1 R2 R3 R4) which may coordinate divalent copper ions to form neurofibrillary tangles (NFTs) and generate reactive oxygen species (ROS).The abnormal amount of Cu2+ accumulation in the intracellular environment, regulating the biological systems is not clearly understood.MethodThe main objective of this study was to evaluate the coordination of four R peptides to Cu2+ by MALDI‐MS‐TOF and determine the interaction of Cu2+ ions with peptides (R1 R2 R3 R4) of Tau protein in vitro. Also, their role in the formation of ROS with a natural reducing agent‐ ascorbate was probed.ResultAs the principal findings of this experiment, metal ion coordinated all 4 R peptides, via His and Cys residue including N terminal and amide groups. All the metallo‐peptide complexes were singly charged peaks, and observed even in the presence of ascorbate. R2 and R3 peptides formed the homodimers by disulfide bond formation. The metallo‐peptides were antioxidants and prooxidants depending on the conditions, indicating that a complex behavior may exist in the biological setting.ConclusionThis work indicates that metal ions interact with R peptides, which may mitigate ROS levels. The finding of this study is greatly beneficial for understanding the Tau protein behavior to develop a potential medication.

A split-type photoelectrochemical immunosensing platform based on atom-efficient cation exchange for physiological monitoring

Ultrasensitive and accurate physiological monitoring is of great significance for disease diagnosis and treatment. In this project, an efficient photoelectrochemical (PEC) split-type sensor on the basis of controlled release strategy was established with great success. Heterojunction formation between g-C3N4 and Zn-doped CdS improved the visible light absorption efficiency, reduced carrier complexation, improved the PEC signal, and increased the stability of the PEC platform. Compared to the traditional model of immunosensors, the process of antigen-antibody specific binding was done in a 96 microplate, and the sensor separated the immune reaction from the photoelectrochemical conversion process, eliminating mutual interference. Cu2O nanocubes were used to label the second antibody (Ab2), and acid etching using HNO3 released a large amount of divalent copper ions, which exchanged cations with Cd2+ in the substrate material, causing a sharp drop in photocurrent and improving the sensitivity of the sensor. Under the optimized experimental conditions, the PEC sensor based on the controlled release strategy for CYFRA21-1 target detection had a wide concentration linear range of 5 × 10−5 to 100 ng/mL with a low detection limit of 0.0167 pg/mL (S/N = 3). This intelligent response variation pattern could also offer the possibility of additional clinical applications for other target detection.

One positive part of copper ion on biocatalysts: CNPs@Cu-Trypsin-assisted aqueous extraction technique for simultaneous exploration of edible insect oil and protein

Edible insects are rich in oil and protein resources, and has it become increasingly important to develop them reasonably when resources are increasingly scarce. However, due to the challenges in recovering enzymes in the enzyme-assisted aqueous extraction technique and the remaining organic solvents in the extraction process based on organic solvent, it is difficult to achieve simultaneous utilization of oil and protein from edible insects. Hence, an improved enzyme-assisted aqueous extraction process based on the assistance of chitosan cross-linked Fe3O4 nanoparticles (CNPs) immobilized enzymes and divalent copper ions chelation, CNPs@Cu-Trypsin-assisted aqueous extraction technique, was first proposed. The hydrolysis activity was significantly increased by 6.16 times, and the value of Kcat/Km was increased by 1.7 times for the results of the formation of the hydrophilic microenvironment. Furthermore, the extraction ratio of silkworm pupae oil extracted via CNPs@Cu-Trypsin-assisted aqueous extraction technique could be increased to 93%, and the oil extraction rate could be maintained above 65% after 10 times reused. Improvement of enzyme-assisted aqueous extraction under the addition of divalent copper ions could achieve an ideal effect of oil extracted from silkworm pupae with less time. Additionally, the quality of silkworm pupae oil was significantly improved and the silkworm pupae protein hydrolysate also showed improved biological activity. Therefore, the enzyme-assisted aqueous extraction enhancement by trypsin immobilization and divalent copper ion chelation is a promising strategy for the green and sustainable exploration of edible insect oil and protein without the use of organic solvents.

Synthesis and Characterization of 5-Chloro 2-furaldehyde Thiosemicarbazone and Its Nickel, Copper and Zinc Complexes

The aim of the present study was to synthesize and characterize of divalent metal ions of Nickel, Copper and Zinc complexes of 5-chloro 2-furaldehyde thiosemicarbazone. Firstly ligand was prepared from the reaction between 5-Chloro-2-furaldehyde and thiosemicarbazide, the second step involved the synthesis of Ni(II), Cu(II) and Zn(II) complexes of 5-chloro 2-furaldehyde thiosemicarbazone. The prepared compounds (ligand or complex) was characterized using different analytical techniques such as elemental analysis, and IR, UV, Mass and 1H NMR tests, the results obtained showed that the ligand and its Ni(II), Cu(II), Zn(II) and Co(II) complexes of 5-chloro 2-furaldehyde thiosemicarbazone were prepared successfully.

Synthesis of copper nanosquare and nanorectangular using novel precursor (substituted benzoic acid complexes)

The ligand 3,4,5-trimethoxybenzoic acid was used to prepare a series of its complexes with divalent manganese, cobalt, nickel and copper ions in a molar ratio of 2 ligand: 1 metal to give the complexes of formula [M(TMA)2].xH2O, M = Mn, Co; x = 0 or M = Ni, Cu; x = 2. The prepared complexes were characterized using FTIR, UV–Vis, CHN, molar conductivity, thermal analysis and magnetic susceptibility. The measurements proved that the TMA anion has the ability to bind with the studied metals by the behaviour of the bidentate chelate through the oxygen atoms of the carboxylic group. The complex [Cu(TMA)2] was used as a starting material to prepare copper nanoparticles using ascorbic acid in the presence of tween as a dispersant, which was characterized by X-ray diffraction and TEM technique. The TEM measurement proves that the copper was prepared with nanoscale with rectangular (53*70 nm) and square (30–32*30–32 nm) nanoparticles and the X-ray diffraction measurement proved that the formed copper was of high purity.

Hybridized Ag-CuCrO2 Nanostructured Composites for Enhanced Gas Sensing

Because of the special layered structure and catalytic properties, delafossite CuCrO2 has been extensively studied and can obtain outstanding performance by noble metal coupling. In this work, the Ag-decorated CuCrO2 hybridizations have been elaborated by a thermal evaporation method. Surface morphology characterization and chemical state analysis were combined to indicate that the isolated island distribution of Ag nanoclusters and the generation of a divalent copper ion may result in an improvement in the gas response toward 100 ppm volatile organic compounds, such as formaldehyde (38.7%), methanol (56.8%), and acetone (76.3%). First-principle calculations were carried out to demonstrate the sensing mechanism of the Ag-decorated CuCrO2, where the remarkable change in geometry and electronic structure provided the active interface and noble metal catalysis effect promoting the target gas adsorption and reaction process. Therefore, in this work, we propose that the thermal evaporation can be utilized to act as a controllable modification method to construct nanostructure gas sensors, and the fundamental enhancement mechanism is useful to guide the design of efficient delafossite-based composite catalysts.