High Concentrations Of Copper Ions Research Articles

Influence of Copper on Oleidesulfovibrio alaskensis G20 Biofilm Formation.

Copper is known to have toxic effects on bacterial growth. This study aimed to determine the influence of copper ions on Oleidesulfovibrio alaskensis G20 biofilm formation in a lactate-C medium supplemented with variable copper ion concentrations. OA G20, when grown in media supplemented with high copper ion concentrations of 5, 15, and 30 µM, exhibited inhibited growth in its planktonic state. Conversely, under similar copper concentrations, OA G20 demonstrated enhanced biofilm formation on glass coupons. Microscopic studies revealed that biofilms exposed to copper stress demonstrated a change in cellular morphology and more accumulation of carbohydrates and proteins than controls. Consistent with these findings, sulfur (dsrA, dsrB, sat, aprA) and electron transport (NiFeSe, NiFe, ldh, cyt3) genes, polysaccharide synthesis (poI), and genes involved in stress response (sodB) were significantly upregulated in copper-induced biofilms, while genes (ftsZ, ftsA, ftsQ) related to cellular division were negatively regulated compared to controls. These results indicate that the presence of copper ions triggers alterations in cellular morphology and gene expression levels in OA G20, impacting cell attachment and EPS production. This adaptation, characterized by increased biofilm formation, represents a crucial strategy employed by OA G20 to resist metal ion stress.

An ESIPT active coumarin-diphenyl azine-based AIEgen: Nanomolar Cu2+ ion sensing, Latent Fingerprinting, live-cell imaging, and real sample analysis

Designing economical and sensitive chemosensors for detecting important metal ions, like Cu2+ ions, is essential and remains a hot topic worldwide. In this investigation, we extended our investigation to design a specific diphenyl-azine-based skeletal system for the selective and sensitive detection of Cu2+ions. We reported a coumarin-diphenyl-azine-based AIEgen (C-1) using an improvised methodology with a large Stoke's shift (∼245 nm) for precisely sensing copper ions in solid, solution, and biological cells. The AIE-ESIPT properties of C-1 were validated using various sophisticated techniques. C-1 was found to be a promising selective and sensitive sensor of Cu2+ ions (nanomolar LOD value ∼10.38 nM) via colorimetric and TURNOFF fluorometric ways. The practical applicability of C-1 was analyzed via real-time estimation of copper ions in water samples (obtained from three varied locations) and in biological samples (urine and serum). The satisfactory recovery with a low RSD value indicates the potential of C-1 in detecting copper ions in actual samples. Estimating copper ions in urine and blood samples demonstrates the usefulness of C-1 in diagnosing disorders like Wilson's disease, which is caused by high concentrations of copper ions in the body. Additionally, we have detected Cu2+ions in live cells (HeLa cells) and carried out Latent Fingerprinting (Level 1 and Level 2) to validate its versatility in physiological and forensic applications. Overall, the proposed C-1 AIEgen is an ultrasensitive Cu2+ions sensor with innumerable applications in the physical world.

Metabolomic changes in Cryptocaryon irritans from Larimichthys crocea after exposure to copper plate.

Cryptocaryon irritans is a highly detrimental parasite in mariculture, causing significant economic losses to the aquaculture industry of Larimichthys crocea. In recent years, copper and copper alloy materials have been used to kill parasites. In this study, the effect of copper plates on the tomont period of C. irritans was explored. The findings indicated that copper plates effectively eradicated tomonts, resulting in a hatching rate of 0. The metabolomic analysis revealed that a total of 2,663 differentially expressed metabolites (1,032 up-regulated and 1,631 down-regulated) were screened in the positive ion mode, and 2,199 differentially expressed metabolites (840 up-regulated and 1,359 down-regulated) were screened in the negative ion mode. L-arginine and L-aspartic acid could be used as potential biomarkers. Copper plate treatment affected 25 metabolic pathways in the tomont, most notably influencing histidine metabolism, retinol metabolism, the biosynthesis of phenylalanine, tyrosine, and tryptophan, as well as arginine and proline metabolism. It was shown that high concentrations of copper ions caused a certain degree of disruption to the metabolome of tomonts in C. irritans, thereby impacting their metabolic processes. Consequently, this disturbance ultimately leads to the rapid demise of tomonts upon exposure to copper plates. The metabolomic changes observed in this study elucidate the lethal impact of copper on C. irritans tomonts, providing valuable reference data for the prevention and control of C. irritans in aquaculture.

Modification of Ti/Sb-SnO2/PbO2 Electrode by Active Granules and Its Application in Wastewater Containing Copper Ions

Active granule (WC/Co3O4) doping Ti/Sb-SnO2/PbO2 electrodes were successfully synthesized by composite electrodeposition. The as-prepared electrodes were systematically characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical performance, zeta potential, and accelerated lifetime. It was found that the doping of active granules (WC/Co3O4) can reduce the average grain size and increase the number of active sites on the electrode surface. Moreover, it can improve the proportion of surface oxygen vacancies and non-stoichiometric PbO2, resulting in an outstanding conductivity, which can improve the electron transfer and catalytic activity of the electrode. Electrochemical measurements imply that Ti/Sb-SnO2/Co3O4-PbO2 and Ti/Sb-SnO2/WC-Co3O4-PbO2 electrodes have superior oxygen evolution reactions (OERs) relative to those of Ti/Sb-SnO2/PbO2 and Ti/Sb-SnO2/WC-PbO2 electrodes. A Ti/Sb-SnO2/Co3O4-PbO2 electrode is considered as the optimal modified electrode due to its long lifetime (684 h) and the remarkable stability of plating solutions. The treatment of copper wastewater suggests that composite electrodes exhibit low cell voltage and excellent extraction efficiency. Furthermore, pilot simulation tests verified that a composite electrode consumes less energy than other electrodes. Therefore, it is inferred that composite electrodes may be promising for the treatment of wastewater containing high concentrations of copper ions.

Adsorption behavior and mechanism of copper ions in the sulfidization flotation of malachite

Malachite is one of the main minerals used for the industrial enrichment and recovery of copper oxide resources, and copper ions are unavoidable metal ions in the flotation pulp. The microflotation, contact angle, and adsorption experiments indicated that pretreatment with an appropriate concentration of copper ions could improve the malachite recovery, and the addition of excess copper ions reduced the hydrophobicity of the malachite surface. The results of zeta potential tests indicated that sodium sulfide and butyl xanthate were also adsorbed on the surface of malachite pretreated with copper ions. X-ray photoelectron spectroscopy (XPS) results indicated that —Cu—O and —Cu—OH bonds were formed on the surface of the samples. After pretreatment with an appropriate concentration of copper ions, the number of —OH groups on the mineral surface decreased, whereas the number of Cu—S groups on the mineral surface increased, which was conducive to the sulfidization of malachite. After adding a high concentration of copper ions, the —OH groups on the mineral surface increased, whereas the number of Cu—S groups decreased, which had an adverse effect on the sulfidization flotation of malachite. Time-of-flight secondary ion mass spectrometry showed that pretreatment with copper ions resulted in a thicker sulfidization layer on the mineral surface.

Study on Properties of Copper-Contaminated Soil Solidified by Solid Waste System Combined with Cement

Three industrial solid wastes including red mud, carbide slag, and phosphogypsum combined with ordinary Portland cement were used as curing agents to solidify/stabilize loess polluted by a high concentration of copper ions. The unconfined compressive strength, resistivity, permeability coefficient, copper ion leaching concentration, pH value, and other engineering application evaluation indexes were analyzed to preliminarily assess the applicability of the curing agent in the remediation of soil contaminated with a high concentration of copper ions. The mineral phases and functional groups of solidified soil were detected using XRD and FTIR, showing that the strength, electrical resistivity, and pH value of solidified soil decrease following the addition of copper ions. Moreover, the strength and resistivity of solidified soil increase with the curing age, and the pH value decreases with age. For solidified contaminated soil, when the total content of curing agent increases from 10 to 20%, the maximum 28 d strength increases from 1.35 to 5.43 MPa, and in this study, its permeability coefficient, copper ion leaching concentration, and pH value were found to be within the limits set by relevant national standards. In conclusion, red mud-carbide slag-phosphogypsum combined with cement has a good stabilizing effect on sites polluted with a high concentration of copper ions.

Interaction mechanism of copper ions with the surface of sulfidized malachite and its response to flotation

The copper ion is a common metal ion in the pulp in the beneficiation industry, and it affects the recovery of the target minerals. In this study, we investigated the interaction mechanism of copper ions with the surface of sulfidized malachite and its effect on flotation. The flotation behavior and surface hydrophobicity were studied by microflotation and contact-angle tests. The experimental results showed that the hydrophobicity of sulfidized malachite modified by a suitable concentration of copper ions was enhanced and the recovery increased. However, after high-concentration copper-ion treatment, the surface hydrophobicity and flotation recovery decreased. Adsorption tests of the collector showed that the collector consumption of sulfidized malachite modified by an appropriate amount of copper ions decreased. According to zeta-potential measurement and X-ray photoelectron spectroscopy analysis, after modification with an appropriate copper-ion concentration, the less reactive –OH component was reduced and the Cu–S component was increased, indicating that the reaction activity and sulfidization product activity of the mineral surface improved. After modification with a high copper-ion concentration, a large number of copper hydroxide complexes formed, resulting in a decrease of the mineral surface reaction activity. Finally, the sulfidization layer on the mineral surface modified by an appropriate amount of copper ions was visually characterized by time-of-flight secondary-ion mass spectroscopy.

Investigation on the copper ion removal potential of a facile-fabricated foamed geopolymer sphere for wastewater remediation

Heavy metal contamination is regarded as one of the most serious hazards to the environment and living organism. The scenario is exacerbating especially due to the continuous development. Therefore, the goal of this study is to examine the copper ion removal potential of a facile-fabricated foamed geopolymer sphere. The foamed geopolymer sphere is synthesized via direct moulding method, using locally available materials of fly ash and calcined kaolin as the starting materials. The foamed geopolymer sphere is beneficial in terms of the ease of use where it can be used in packed bed system directly and the retrieval process upon exhausted is much simpler. Due to the plentiful binding sites created by foaming of the geopolymer sphere, the copper ion removal efficiency increases from 47.5% to 92.8% and the removal capacity improves by six times. pH 5 is identified to be the best pH for copper ion removal utilizing the foamed geopolymer sphere. The maximum copper ion removal capacity found experimentally is 37.9 mg/g, which is satisfactory compared to the foamed geopolymer spheres prepared via suspension and solidification. Meanwhile, increasing the dosage of the foamed geopolymer sphere can increase the foamed geopolymer sphere’s removal ability when concerning high copper ion concentration. Pseudo second-order kinetic and Langmuir isotherm models are found to describe well the adsorption process.

Enhanced copper removal and bioelectricity generation in sediment microbial fuel cells through biostimulation and bioaugmentation

Unlike conventional sediment microbial fuel cell (SMFC), a single medium SMFC is a cathode embedded in an anoxic sediment environment to avoid electron competition from oxygen and to increase the chance of copper ions being removed by reduction as electron acceptors. The high concentration of copper ions in the sediment limits microbial activity, and therefore an effective method to be proposed to overcome this problem. The carboxymethyl cellulose (CMC) immobilized beads containing copper-tolerant bacteria have multiple functions, including adsorption of copper ions, protection of copper-tolerant bacteria from inhibition by high concentrations of copper ions, and promotion of copper-tolerant bacteria activity as a co-substrate. The results show that copper-tolerant Ochrobactrum oryzae had improved organic removal (85%) at high concentrations of copper ions, which was 1.48–1.65 times and 5 times more effective than those containing other strains and mixed bacteria. Immobilization of Ochrobactrum oryzae with CMC reduced the inhibition of Ochrobactrum oryzae by copper in the sediment and ensured the stable generation of electricity by the SMFC. When cell-immobilized beads were added to the anode zone of SMFC, the maximum output voltage (173.9 mV) and copper ion removal efficiency (74%) were 2.89 and 1.15 times higher than the output voltage and removal efficiency achieved without bead addition, respectively. The dominant bacteria in the anode zone on day 70 were electrochemically active species capable of degrading organic compounds. SMFC combining biosorption, biostimulation, and bioaugmentation technologies was developed in this study for the remediation of sediment containing high concentrations of copper ion.

The role of polyhydroxyalkanoates in adaptation of Cupriavidus necator to osmotic pressure and high concentration of copper ions

Polyhydroxyalkanoates (PHA) are abundant microbial polyesters accumulated in the form of intracellular granules by numerous prokaryotes primarily as storage of carbon and energy. Apart from their storage function, the presence of PHA also enhances the robustness of the microbial cells against various stressors. In this work, we investigated the role of PHA in Cupriavidus necator, a model organism concerning PHA metabolism, for adaptation to osmotic pressure and copper ions. In long-term laboratory evolution experiments, the bacterial culture was cultivated in presence of elevated doses of sodium chloride or copper ions (incubations lasted 78 passages for Cu2+ and 68 passages for NaCl) and the evolved strains were compared with the wild-type strain in terms of growth and PHA production capacity, cell morphology (investigated by various electron microscopy techniques), activities of selected enzymes involved in PHA metabolism and other crucial metabolic pathways, the chemical composition of bacterial biomass (determined by infrared and Raman spectroscopy) and also considering robustness against various stressors. The results confirmed the important role of PHA metabolism for adaptation to both tested stressors.

A novel Cu-bearing high-entropy alloy with significant antibacterial behavior against corrosive marine biofilms

The design of novel high-entropy alloys (HEAs) provides a unique opportunity for the development of structure-function integrated materials with high mechanical and antimicrobial properties. In this study, by employing the antibacterial effect of copper, a novel Al0.4CoCrCuFeNi HEA with broad-spectrum antibacterial and strong mechanical properties was designed. High concentrations of copper ions released from the HEA prevented growth and biofilm formation by biocorrosive marine bacterial species. These findings serve as a proof-of-concept for further development of unique HEA materials with high antimicrobial efficiency and mechanical properties, compared to conventional antibacterial alloys.

Acclimation of copper absorption ability of Candida utilis

The use of inorganic copper in feed is hazardous. As probiotics of animals, Candida utilis can absorb copper ions and transform them to organic copper. This study aimed to domesticate the ability of C. utilis (CICC 32211) to absorb and transform copper ions. So, C. utilis (CICC 32211) was cultured in media with different concentrations of copper ions for 24, 48 and 72 h to identify the optimum copper ion concentration. C. utilis (CICC 32211) strains were domesticated for three generations, then the absorption and distribution of copper ions in the yeast cells were studied. We found that the optimum concentration of copper ions was 110 µg/mL. After 48 h, the number of yeast cells was low, but copper ion absorption efficiency was maximized (43.83%). Most of the enriched copper ions were distributed in the yeast cell wall (up to 30.58% when grown in the medium with 110 µg/mL copper ions), while the intracellular copper ion content was low (2.095%). High concentrations of copper ions affected the morphological structure, element content and distribution of yeast cells.

Understanding Amyloid-Beta Plaque Formation By Monitoring the Redox Activity of Copper at the Active Site

Alzheimer’s patients are found to have high concentrations of Amyloid-Beta peptide (Aβ-42), an overexpressed 42 amino acid sequence, along with a high concentration of copper ions in the brain. The Aβ-42 peptide results from the cleavage of a precursor protein (APP) and aggregates to form beta sheets during post-translational modification due to oxidative stress. Free metal ions, particularly Cu2+, initiate this oxidative stress by binding to the 14th Histidine residue in the primary structure of Aβ-42 and undergoing a single electron-transfer reduction to Cu+. This redox activity ultimately generates reactive oxygen species (ROS) through Fenton Decomposition to produce hydroxyl radicals within the brain. ROS initiate the progressive transitive states of Aβ-42 from fibril to oligomer to finally aggregate plaque formation, which causes cellular degeneration. The work presented here specifically focuses on the copper redox activity in the biological pathway leading to Alzheimer’s disease. The redox activity of copper at the active site is monitored and correlated to the degree of Aβ-42 fibrillization and aggregation, which is examined using Atomic Force Microscopy (AFM). Evaluating the copper-mediated toxicity will allow for a better understanding of the electrochemical process that initiates ROS and ultimately leads to Aβ-42 plaque formation.

Green synthesis and characterization of ultrafine copper oxide reduced graphene oxide (CuO/rGO) nanocomposite

Ultrafine and water-dispersive CuO/reduced graphene oxide (CuO/rGO) nanocomposite was prepared by environmentally friendly approach, which displays much better antibacterial properties than that of Cu+2/GO and CuO nanoparticles. The obtained CuO/rGO is characterized with XRD, Raman spectroscopy, SEM, TEM, EIS and so on. The merit of this method is that the diameter of CuO nanoparticles decorated by rGO is in the range of 3–5nm. The MIC value is only 1.2 and 1.8μgmL−1 against E. coli and S. aureus, respectively. Moreover, the CuO/rGO demonstrates very low release of Cu+2 which can prevent from serious safety problems due to possible high concentrations of copper ions in long-term continuous application.

A novel recovery method of copper from waste printed circuit boards by supercritical methanol process: Preparation of ultrafine copper materials

In this study, supercritical methanol (SCM) process was successfully used for the preparation of ultrafine copper materials from waste printed circuit boards (PCBs) after nitric acid pretreatment. Waste PCBs were pretreated twice in nitric acid. Sn and Pb were recovered by the first nitric acid pretreatment. The leach liquor with a high concentration of copper ions after the second nitric acid leaching was subjected to SCM process. The mixture of Cu and Cu2O with poor uniformity of particle size was formed due to the effect of ferric iron contained in the leach liquor of waste PCBs, while more uniform and spherical Cu particles with high monodispersity and smaller size could be prepared after the removal of Fe. The size of Cu particles increased obviously with the decline of SCM temperature, and particles became highly aggregated when the reaction temperature decreased to 300°C. The size of Cu particles decreased markedly with the decrease of initial concentration of copper ion in the leach liquor of waste PCBs. It is believed that the process developed in this study is simple and practical for the preparation of ultrafine copper materials from waste PCBs with the aim of recycling these waste resources as a high value-added product.

A versatile and efficient markerless gene disruption system for Acidithiobacillus thiooxidans: application for characterizing a copper tolerance related multicopper oxidase gene.

The acidophilic bioleaching bacteria can usually survive in high concentrations of copper ions because of their special living environment. However, little is known about the copper homeostatic mechanisms of Acidithiobacillus thiooxidans, an important member of bioleaching bacteria. Here, a putative multicopper oxidase gene (cueO) was detected from the draft genome of A. thiooxidans ATCC 19377. The transcriptional level of cueO in response to 10 mM CuSO₄was upregulated 25.01 ± 2.59 folds. The response of P(cueO) to copper was also detected and might be stimulated by a putative CueR protein. Then, by using the counter-selectable marker lacZ and enhancing the expression of endonuclease I-SceI with tac promoter, a modified markerless gene disruption system was developed and the cueO gene disruption mutant (ΔcueO) of A. thiooxidans was successfully constructed with a markedly improved second homologous recombination frequency of 0.28 ± 0.048. The ΔcueO mutant was more sensitive to external copper and nearly completely lost the phenoloxidase activity; however, the activity could be restored after complementing the cueO gene. All results suggest the close relation of cueO gene to copper tolerance in A. thiooxidans. In addition, the developed efficient markerless gene knockout method can also be introduced into other Acidithiobacillus strains.

Copper Ion Assisted Reshaping and Etching of Gold Nanorods: Mechanism Studies and Applications

This article describes copper ion assisted end-cap morphology transformation and anisotropic etching of gold nanorods (GNRs) under mild conditions. The copper ions are proposed to catalyze the oxidation of the GNRs by dissolved oxygen. We suggest that the surface Au atoms with high surface energy are stabilized by forming Au–O complexes (termed as static adsorbed oxygen). At low concentration of copper ions, the Au–O complexes are removed by oxidative etching, thus leaving a “clean” Au surface. Such a clean surface can relax to a more stable state via surface atom diffusion, leading to the GNR end-cap morphology variation. This is the first time that the existence of adsorbed oxygen species on the surface of the GNRs is probed and demonstrated. At high concentration of copper ions, anisotropic etching of the GNRs is initiated by dissolved oxygen (termed as dynamic adsorbed oxygen) and leads to shorter GNRs. For other etch agents such as H2O2 and Fe3+, addition of copper ions produces a synergistic effect. Due to the high affinity of oxygen to silver and palladium, such synergistic etching is observed in Au@Ag NRs and Au@Pd NRs as well. These interesting findings provide a new way to probe the surface reactivity of noble metal nanocrystals.

Fabrication of Highly Porous Platinum by Cyclic Electrodeposition of PtCu Alloys: How do Process Parameters Affect Morphology?

In this work we analyze the influence of process parameters on the morphology of highly porous platinum electrodes, fabricated by co-deposition of platinum-copper alloy and subsequent selective dissolution of the less noble copper during multiple cyclic voltammetry scans. Thereto the Cu2+ concentration in the deposition electrolyte, the negative scan limit, and the scan rate were varied. Corresponding electrodes were characterized by their surface texture (scanning electron microscopy, X-ray diffractometry), specific surface area, and elemental compositions (X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy). Under conditions enforcing precursor depletion a sphere-dominated structure is observed, whereas oppositional configurations lead to smoother, mud-crack pattern like structures. Electrodes of high specific surface area are obtained particularly when high copper ion concentrations (100 mmol l−1 CuSO4, roughness factor 3740 ± 270), high negative scan limits (−0.800 V vs. SCE, roughness factor 3790 ± 370) and low scan speeds (1 mV s−1, roughness factor 3930 ± 370) compared to standard parameters (20 mmol l−1 CuSO4, −0.600 V vs. SCE negative scan limit, 1 mV s−1, roughness factor 3040 ± 300) were applied during fabrication. Since the fabrication of these highly rough electrodes requires the deposition of high amounts of platinum (10–20 mg per cm2 footprint area) it is mainly relevant to applications such as neurostimulation electrodes or implantable glucose fuel cells in which platinum costs are less relevant than electrode properties and functionality.

Copper ions removal from liquid phase by polyethersulfone (PES) membranes functionalized by introduction of carbonaceous materials

The method of synthesis of polymeric membranes based on polyethersulfone (PES) and modified by addition of carbonaceous materials (char or activated carbon) is presented and their potential application for removal of copper ions from liquid phase are examined. The addition of carbon brings about changes in the content of the surface oxygen group but has no significant effect on the chemical character of the groups, and acidic groups dominate. After filtration of a copper solution the total content of surface oxides considerably increases but the acidic groups remain dominant. Modification of PES membrane by addition of carbonaceous materials was found to strongly increase the membrane effectiveness in copper ions removal. The membrane with addition of char is the most effective at low copper concentrations, while the membrane with addition of activated carbon is the best at high concentrations of copper ions.

Characterization of Lactobacillus brevis L62 strain, highly tolerant to copper ions

Lactic acid bacteria (LAB) as starter culture in food industry must be suitable for large-scale industrial production and possess the ability to survive in unfavorable processes and storage conditions. Approaches taken to address these problems include the selection of stress-resistant strains. In food industry, LAB are often exposed to metal ions induced stress. The interactions between LAB and metal ions are very poorly investigated. Because of that, the influence of non-toxic, toxic and antioxidant metal ions (Zn, Cu, and Mn) on growth, acid production, metal ions binding capacity of wild and adapted species of Leuconostoc mesenteroides L3, Lactobacillus brevis L62 and Lactobacillus plantarum L73 were investigated. The proteomic approach was applied to clarify how the LAB cells, especially the adapted ones, protect themselves and tolerate high concentrations of toxic metal ions. Results have shown that Zn and Mn addition into MRS medium in the investigated concentrations did not have effect on the bacterial growth and acid production, while copper ions were highly toxic, especially in static conditions. Leuc. mesenteroides L3 was the most efficient in Zn binding processes among the chosen LAB species, while L. plantarum L73 accumulated the highest concentration of Mn. L. brevis L62 was the most copper resistant species. Adaptation had a positive effect on growth and acid production of all species in the presence of copper. However, the adapted species incorporated less metal ions than the wild species. The exception was adapted L. brevis L62 that accumulated high concentration of copper ions in static conditions. The obtained results showed that L. brevis L62 is highly tolerant to copper ions, which allows its use as starter culture in fermentative processes in media with high concentration of copper ions.