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In mineral processing operations, besides target minerals, slurries often contain various metal ions, including common ones with different valence states such as Pb2+, Cu2+, Fe2+, and Fe3+. These metal ions originate from multiple sources during the flotation process, including the dissolution of co-occurring metal minerals during crushing and grinding, the addition of flotation reagents, and the flotation water. Investigators have long recognized that metal ions significantly affect mineral flotation behavior. Due to physical and chemical interactions, some ions in the slurry will interact with target mineral. If these ions form hydrophobic substances on the mineral surface or increase the active sites between the mineral and collectors or sulfide agent, they will have a positive impact on the flotation process. Conversely, if they produce hydrophilic substances or deplete added collectors and sulfides, they negatively impact mineral enrichment. Meanwhile, metal ions can regulate the electrostatic repulsion between reagents and mineral surfaces in the slurry system, which has a certain impact on the flotation results. This study provides a comprehensive overview of the sources of metal ions in flotation, explores their adsorption characteristics on mineral surfaces, and examines their impact on the flotation process. It provides a theoretical basis for improving mineral flotation processes in the presence of metal ions. [ABSTRACT FROM AUTHOR]

In this study, a novel bionic periosteum (BP)‐bioactive glass fiber membrane (BGFM) is designed. The introduction of magnesium ion (Mg2+) and zinc ion (Zn2+) change the phase separation during the electrospinning (ES) jet stretching process. The fiber's pore structure transitions from connected to closed pores, resulting in a decrease in the rapid release of metal ions while also improving degradation via reducing filling quality. Additionally, the introduction of magnesium (Mg) and zinc (Zn) lead to the formation of negative charged tetrahedral units (MgO42− and ZnO42−) in the glass network. These units effectively trap positive charged metal ions, further inhibiting ion release. In vitro experiments reveal that the deigned bionic periosteum regulates the polarization of macrophages toward M2 type, thereby establishing a conducive immune environment for osteogenic differentiation. Bioinformatics analysis indicate that BP enhanced bone repair via the JAK‐STAT signaling pathway. The slow release of metal ions from the bionic periosteum can directly enhance osteogenic differentiation and vascularization, thereby accelerating bone regeneration. Finally, the bionic periosteum exhibits remarkable capabilities in angiogenesis and osteogenesis, demonstrating its potential for bone repair in a rat calvarial defect model. [ABSTRACT FROM AUTHOR]

Prussian blue analogues are highly promising electrode materials due to their versatile electrochemical activity and low cost. However, they often suffer from severe structural damage caused by the Jahn–Teller distortion and dissolution of high‐spin outer metal ions, resulting in poor cycle life. Material modification and electrolyte regulation have been the common approaches to address this issue, albeit with very limited success. We report here a novel and efficient strategy to preserve structural stability by co‐inserting Co2+ and Zn2+ ions in KCo[Fe(CN)6]. This co‐insertion induced a spontaneous and reversible phase conversion by the replacement of low‐spin inner ion (Fe3+), which efficiently relieves structural damage caused by Jahn–Teller distortion and metal‐ion dissolution, leading to an outstanding Zn2+ storage capacity and an exceptional improvement of cycle life with a capacity retention of 97.7 % over 4400 cycles at 40 C. We also demonstrated the enhancement of co‐intercalation on ion migration using a combined approach of experimental and density functional theory (DFT) calculations. This work provides an important progress to solve the cycle stability of Prussian blue analogues towards their practical application as electrode materials for aqueous batteries. [ABSTRACT FROM AUTHOR]

To elucidate the inhibition effects of Zn2+ and Cd2+ on the luciferin–luciferase reaction, we performed quantitative measurements of quantum yields and spectral shapes for in vitro firefly bioluminescence in aqueous solutions containing ZnSO4, ZnCl2, CdSO4, and CdCl2 at different concentrations. Particular care was taken toward the equilibrium between metal ions and enzyme proteins, anion difference, solubility, and uncertainty evaluation. The bioluminescence quantum yields decreased almost linearly to the concentration of Zn2+ and Cd2+ below 0.25 mM. No obvious difference was found between the chloride and sulfate anion solutions. We defined inhibition sensitivity as the decrease in relative quantum yield versus the concentration of metal ions, and they were determined to be 1.48 ± 0.13 and 1.13 ± 0.16/mM for Zn2+ and Cd2+, respectively. We estimated the detection limit of inhibition effects as the concentration of metal ions that decrease relative quantum yields by 10%, which were 0.07 mM (4 ppm) and 0.09 mM (10 ppm) for Zn2+ and Cd2+, respectively. The shape of the bioluminescence spectra changed sensitively with the increase in Zn2+ concentrations. The bioluminescence peak energy for 0.10‐mM Zn2+ was ~2.2 eV, while that for 0.25‐mM Zn2+ was ~2.0 eV. The shape of the spectra changed less sensitively with the increase in Cd2+concentrations, and the peak energy was at ~2.2 eV for Cd2+ concentrations of 0.10 and 0.25 mM. [ABSTRACT FROM AUTHOR]

The synthesis of the title compound, [Zn(C4H6N2)6](NO3)2, is described. This complex consists of a central zinc metal ion surrounded by six 1-methylimidazole ligands, charge balanced by two nitrate anions. The complex crystallizes in the space group P3. In the crystal, the nitrate ions are situated within the cavities created by the [Zn(N-Melm)6] 2+ cations, serving as counter-ions. The three oxygen atoms of the nitrate ion engage in weak C—H...O interactions. In addition to single-crystal X-ray diffraction analysis, the complex was characterized using elemental analysis, ¹ H NMR, 13C NMR, and FTIR spectroscopy. [ABSTRACT FROM AUTHOR]

Advance in the design of molecular photoswitches ‐ adapters that convert light into changes at molecular level ‐ opens up exciting possibilities in preparing smart polymers, drugs photoactivated inside humans, or light‐fueled nanomachines that might in the future operate in our bloodstream. Hemipiperazines are recently reported biocompatible molecular photoswitches based on cyclic dipeptides. Here we report a multistimuli‐responsive hemipiperazine‐based switch that reacts on light, solvents, acidity, or metal ions. Its photoequilibration is controlled by the intramolecular hydrogen bonding pattern. The compound can be used as a mid‐nanomolar photoswitchable fluorescent sensor for zinc and cadmium ions, applicable to monitor environmental pollution in real time. [ABSTRACT FROM AUTHOR]

The synthesis of the title compound, [Zn(C4H6N2)6](NO3)2, is described. This complex consists of a central zinc metal ion surrounded by six 1-methyl­imidazole ligands, charge balanced by two nitrate anions. The complex crystallizes in the space group P[\overline{3}]. In the crystal, the nitrate ions are situated within the cavities created by the [Zn(N-Melm)6]2+ cations, serving as counter-ions. The three oxygen atoms of the nitrate ion engage in weak C--H⋯O inter­actions. In addition to single-crystal X-ray diffraction analysis, the complex was characterized using elemental analysis, 1H NMR, 13C NMR, and FTIR spectroscopy. [ABSTRACT FROM AUTHOR]

Zinc and cadmium pollutants cause a significant environmental effect that cannot be ignored. Due to their considerable amount in an aqueous environment, industries are seeking suitable adsorbents that are environmentally friendly and inexpensive for removing metals from wastewater before disposing of them in surface waters. This research employed original MXene (MX) and chitosan-modified MXene (CSMX) to extract zinc (Zn(II)) and cadmium (Cd(II)) metal ions from water-based solutions. The composite material produced was analyzed using techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET). The effects of contact duration, pH of the solution, and initial concentration of metal ions on the adsorption process of Zn(II) and Cd(II) onto both MX and CSMX composites were investigated. MX and prepared CSMX composite presented a high adsorption capacity for both studied heavy metals, which were 91.55 and 73.82 mg/g for Zn(II) and Cd(II) onto MX, 106.84 and 93.07 mg/g for Cd(II) and Zn(II) onto CSMX composite, respectively. Furthermore, the maximum competitive adsorption capacities for Zn(II) onto MX and CSMX composites are 77.29 and 93.47 mg/g, and for are Cd(II) 60.30 and 79.66 mg/g, respectively. Hence, the removal capacities for both single and competitive metal ions were superior to CSMX composite. However, the adsorption capacities after five successive regeneration sequences were only dropped by 13.2% for Zn(II) and 17.4% for Cd(II) onto the CSMX composite compared to the first cycle. These results confirm that both metals could be efficiently terminated from wastewater, which makes the prepared CSMX composite a favorable candidate adsorbent in practical applications. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries (AZIBs) have received a lot of attention in electrochemical energy storage systems for their low cost, environmental compatibility, and good safety. However, cathode materials still face poor material stability and conductivity, which cause poor reversibility and poor rate performance in AZIBs. Herein, a heterogeneous structure combined with cation pre-intercalation strategies was used to prepare a novel CaV6O16·3H2O@Ni0.24V2O5·nH2O material (CaNiVO) for high-performance Zn storage. Excellent energy storage performance was achieved via the wide interlayer conductive network originating from the interlayer-embedded metal ions and heterointerfaces of the two-phase CaNiVO. Furthermore, this unique structure further showed excellent structural stability and led to fast electron/ion transport dynamics. Benefiting from the heterogeneous structure and cation pre-intercalation strategies, the CaNiVO electrodes showed an impressive specific capacity of 334.7 mAh g−1 at 0.1 A g−1 and a rate performance of 110.3 mAh g−1 at 2 A g−1. Therefore, this paper provides a feasible strategy for designing and optimizing cathode materials with superior Zn ion storage performance. [ABSTRACT FROM AUTHOR]

A new quinoline‐based COF (covalent organic framework), obtained by Povarov reaction, containing 2,6‐diisopropylphenyl moieties as substituents over the heterocyclic ring is described for detecting Zn2+ in aqueous solution. The introduction of the mentioned bulky phenyl rings into the network favors an increase of the distance between the reticular sheets and their arrangement, obtaining a new material with an alternating AB type stacking. The new material exhibits good selectivity to detect Zn2+ by fluorescence emission in aqueous solutions up to a concentration of 1.2 × 10−4 m of the metal ion. In order to have a deeper insight into the interaction between the COF and the zinc cation, a thorough spectroscopical, microscopical, and theoretical study is also presented and discussed in this communication. [ABSTRACT FROM AUTHOR]

A novel fluorescent probe containing an imine structure was synthesized through a condensation reaction based on the skeleton of antipyrine. Due to the synergistic effect of photoinduced electron transfer (PET), excited-state intramolecular proton transfer (ESIPT), and E/Z isomerization, the probe itself has weak fluorescence. When zinc ions are added to the ethanol solution of the probe, the formed complex inhibits PET, ESIPT, and E/Z isomerization while activating chelation-enhanced fluorescence (CHEF), resulting in fluorescent "turn-on" at 462 nm. Under optimal detection conditions, the probe can rapidly respond to zinc ions within 3 min, with a linear range of 60–220 μM and a lower limit of detection (LOD) of 0.63 μM. It can also specifically identify zinc ions in the presence of 13 common metal ions. [ABSTRACT FROM AUTHOR]

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BACKGROUND: Resistance to the inflammatory response is an important part of promoting the repair of damaged tissue and improving the local inflammatory response caused by medical bio-implant materials has been a key issue to be addressed in recent years. OBJECTIVE: To summarize the anti-inflammatory effects of common metal ions and related molecular mechanisms to provide some theoretical references for improving the early inflammatory response of hosts caused by bio-implant materials. METHODS: A computer search of the relevant literature in PubMed, Web of Science, CNKI and WanFang databases was conducted using “metal ions, magnesium ion, zinc ion, silver ion, copper ion, inflammation, anti-inflammatory effects, oxidative stress, immunoregulation, signaling pathways” as Chinese and English search terms. Preliminary screening was conducted by reading the titles and abstracts. Finally, 80 papers were included for result analysis and summary. RESULTS AND CONCLUSION: (1) Metal ions such as magnesium, zinc, silver and copper have a good anti-inflammatory effect. The strength of this antiinflammatory effect is strongly correlated with the dose and duration of action. In the future, consideration can be given to controlling the release rate of ions and adjusting the appropriate therapeutic concentration to achieve the best anti-inflammatory effect. (2) Magnesium ions and zinc ions exhibit excellent antiinflammatory activity, with magnesium ions often being beneficial in anti-inflammatory therapy in the form of compounds such as magnesium sulfate and zinc ions regulating the body’s inflammatory response with zinc feed as the main source of zinc supplementation. (3) Silver and copper ions have some antiinflammatory effects, but are still predominant for their excellent antibacterial activity, mainly in the form of nanoparticles and bio-coatings. (4) Magnesium and zinc metal ions can be combined with natural extracts to form complexes to exert anti-inflammatory effects, and this method has the advantage of being inexpensive and widely available and is a sustainable and green approach, which is worthy of clinical promotion. (5) Metal ions such as magnesium, zinc, silver and copper exert anti-inflammatory effects by reducing host oxidative stress damage, modulating immune cells and inhibiting inflammatory signaling pathways such as nuclear factor-κB, Toll-like receptor, STAT3 and NOD. (6) The molecular mechanism related to the anti-inflammation of metal ions is a complex network, which is not the effect of a single pathway, but should be a combination of multiple signaling pathways. There are still many potential mechanisms that have not yet been explored, and more systematic elucidation of the interconnections between various signaling pathways is needed in the future. [ABSTRACT FROM AUTHOR]

Objective: Synthesis of a series of methylene-imidazolones with complexing groups. Methods: The formation of imines with the following [2+3]-cycloaddition and recycling. The use of phosphazene to form an acyclic analogue. The optical properties were studied with and without ions of metals. The spectrofluorimetric titration was carried out to evaluate the binding constants. Results and Discussion: We discovered that for hydroxyquinolinidene-imidazolone and difluorobenzimidazolidene-imidazolone, which practically did not exhibit fluorescence in the free form, a noticeable increase in fluorescence was observed when binding to the Cd2+ and Zn2+ cations. Conclusions: Two compounds from a new synthesized series were found to be promising fluorescent sensors of cadmium and zinc ions and potential labels for monitoring intracellular processes. [ABSTRACT FROM AUTHOR]

DNAzyme‐based fluorescent probes for imaging metal ions in living cells have received much attention recently. However, employing in situ metal ions imaging within subcellular organelles, such as nucleus, remains a significant challenge. We developed a three‐stranded DNAzyme probe (TSDP) that contained a 20‐base‐pair (20‐bp) recognition site of a CRISPR/Cas9, which blocks the DNAzyme activity. When Cas9, with its specialized nuclear localization function, forms an active complex with sgRNA within the cell nucleus, it cleaves the TSDP at the recognition site, resulting in the in situ formation of catalytic DNAzyme structure. With this design, the CRISPR/Cas9‐inducible imaging of nuclear Zn2+ is demonstrated in living cells. Moreover, the superiority of CRISPR‐DNAzyme for spatiotemporal control imaging was demonstrated by integrating it with photoactivation strategy and Boolean logic gate for dynamic monitoring nuclear Zn2+ in both HeLa cells and mice. Collectively, this conceptual design expands the DNAzyme toolbox for visualizing nuclear metal ions and thus provides new analytical methods for nuclear metal‐associated biology. [ABSTRACT FROM AUTHOR]

Endogenous essential metal ions play an important role in many life processes, especially in tumor development and immune response. The approval of various metallodrugs for tumor therapy brings more attention to the antitumor effect of metal ions. With the deepening understanding of the regulation mechanisms of metal ion homeostasis in vivo, breaking intracellular metal ion homeostasis becomes a new means to inhibit the proliferation of tumor cells and activate antitumor immune response. Diverse nanomedicines with the loading of small molecular ion regulators or metal ions have been developed to disrupt metal ion homeostasis in tumor cells, with higher safety and efficiency than free small molecular ion regulators or metal compounds. This comprehensive review focuses on the latest progress of various intracellular metal ion homeostasis regulation‐based nanomedicines in tumor therapy including calcium ion (Ca2+), ferrous ion (Fe2+), cuprous ion (Cu+), managanese ion (Mn2+), and zinc ion (Zn2+). The physiological functions and homeostasis regulation processes of ions are summarized to guide the design of metal ion regulation‐based nanomedicines. Then the antitumor mechanisms of various ions‐based nanomedicines and some efficient synergistic therapies are highlighted. Finally, the challenges and future developments of ion regulation‐based antitumor therapy are also discussed, hoping to provide a reference for finding more effective metal ions and synergistic therapies. [ABSTRACT FROM AUTHOR]

Bacteria and archaea respond and adapt to environmental stress conditions by modulating the toxin–antitoxin (TA) system for survival. Within the bacterium Helicobacter pylori, the protein HP0894 is a key player in the HP0894-HP0895 TA system, in which HP0894 serves as a toxin and HP0895 as an antitoxin. HP0894 has intrinsic ribonuclease (RNase) activity that regulates gene expression and translation, significantly influencing bacterial physiology and survival. This activity is influenced by the presence of metal ions such as Mg2+. In this study, we explore the metal-dependent RNase activity of HP0894. Surprisingly, all tested metal ions lead to a reduction in RNase activity, with zinc ions (Zn2+) causing the most significant decrease. The secondary structure of HP0894 remained largely unaffected by Zn2+ binding, whereas structural rigidity was notably increased, as revealed using CD analysis. NMR characterized the Zn2+ binding, implicating numerous His, Asp, and Glu residues in HP0894. In summary, these results suggest that metal ions play a regulatory role in the RNase activity of HP0894, contributing to maintaining the toxin molecule in an inactive state under normal conditions. [ABSTRACT FROM AUTHOR]

BACKGROUND: Metal ions play an important role in the human body. With the progress of material synthesis and processing technology, a variety of metal ions that can be used in bone tissue engineering have been developed, such as magnesium (Mg2+), zinc (Zn2+), manganese (Mn2+), strontium (Sr2+), and copper (Cu2+). OBJECTIVE: To summarize the research progress and development direction of metal ions in bone tissue engineering. METHODS: The literature collected by CNKI, PubMed and WanFang databases from 2014 to 2022 was retrieved. The Chinese and English key words were “metal ions, bone tissue engineering, osteogenic activity, magnesium ions, zinc ions, manganese ions, strontium ions, copper ions, calcium ions, lithium ions, cobalt ions”. RESULTS AND CONCLUSION: Different metal ions will be released to varying degrees after the materials are implanted into the body, which can change the tissue microenvironment, thus improving the ability of materials to form blood vessels and bones. Compared with growth factors, metal ions are easier to control the release rate, have lower cost, and can also improve the mechanical properties of implant materials. The application of metal ions in bone tissue engineering is full of prospects. Although some metal ions can already be used to treat bone defects, the mechanism of action of many metal ions in the human body is not completely clear, and the application effect is a lack of clinical experiment verification. Further exploration is needed before clinical application. [ABSTRACT FROM AUTHOR]

Natural Guar gum based resin which containing 6-amino caproic acid as a functional group has been synthesized. This modified ion exchange resin was used for removal of toxic metal ions from synthetic waste water using the principle of ion exchange mechanism. GACA resin was used for removal of ZnII) and Co(II) metal ions from aqueous solution containing these metal ions. Zn(II) ion show maximum adsorption and Kd value at pH 5 while Co(II) show at pH 6. Zn(II) show maximum adsorption on GACA resin is 81.34% and for Co(II) is 73.3% which is good result. [ABSTRACT FROM AUTHOR]

Addressing the growing need for environmentally friendly fungicides in agriculture, this study explored the potential of biopolymer microparticles loaded with metal ions as a novel approach to combat fungal pathogens. Novel alginate microspheres and chitosan/alginate microcapsules loaded with zinc or with zinc and silver ions were prepared and characterized (microparticle size, morphology, topography, encapsulation efficiency, loading capacity, and swelling behavior). Investigation of molecular interactions in microparticles using FTIR-ATR spectroscopy exhibited complex interactions between all constituents. Fitting to the simple Korsmeyer–Peppas empirical model revealed the rate-controlling mechanism of metal ions release from microparticles is Fickian diffusion. Lower values of the release constant k imply a slower release rate of Zn2+ or Ag+ ions from microcapsules compared to that of microspheres. The antimicrobial potential of the new formulations against the fungus Botrytis cinerea was evaluated. When subjected to tests against the fungus, microspheres exhibited superior antifungal activity especially those loaded with both zinc and silver ions, reducing fungal growth up to 98.9% and altering the hyphal structures. Due to the slower release of metal ions, the microcapsule formulations seem suitable for plant protection throughout the growing season. The results showed the potential of these novel microparticles as powerful fungicides in agriculture. [ABSTRACT FROM AUTHOR]

The integration of hydroxyapatite (HA) with broad-spectrum bactericidal nano-silver within biopolymer-based bone scaffolds not only promotes new bone growth, but also effectively prevents bacterial infections. However, there are problems such as a poor interface compatibility and easy agglomeration. In this project, zeolitic imidazolate frameworks (ZIF-8) were grown in situ on nano-HA to construct a core–shell structure, and silver was loaded into the ZIF-8 shell through ion exchange. Finally, the core–shell structure (HA@Ag) was composited with polylactic acid (PLLA) to prepare bone scaffolds. In this case, the metal zinc ions of ZIF-8 could form ionic bonds with the phosphate groups of HA by replacing calcium ions, and the imidazole ligands of ZIF-8 could form hydrogen bonds with the carboxyl groups of the PLLA, thus enhancing the interface compatibility between the biopolymers and ceramics. Additionally, the frame structure of MOFs enabled controlling the release of silver ions to achieve a long-term antibacterial performance. The test results showed that the HA@Ag nanoparticles endowed the scaffold with good antibacterial and osteogenic activity. Significantly, the HA@Ag naoaprticle exhibited a good interfacial compatibility with the PLLA matrix and could be relatively evenly dispersed within the matrix. Moreover, the HA@ZIF-8 also effectively enhanced the mechanical strength and degradation rate of the PLLA scaffold. [ABSTRACT FROM AUTHOR]

Metal ion doped hollow mesoporous ZnMn 2 O 4 /C microspheres were constructed. Among them, the sample 0.1 % Fe-ZnMn 2 O 4 maintains a specific capacity of 121.5 mAh g−1 after 1200 cycles at 1.0 A g−1. [Display omitted] Spinel ZnMn 2 O 4 with a three-dimensional channel structure is one of the important cathode materials for aqueous zinc ions batteries (AZIBs). However, like other manganese-based materials, spinel ZnMn 2 O 4 also has problems such as poor conductivity, slow reaction kinetics and structural instability under long cycles. Herein, ZnMn 2 O 4 mesoporous hollow microspheres with metal ion doping were prepared by a simple spray pyrolysis method and applied to the cathode of aqueous zinc ion battery. Cation doping not only introduces defects, changes the electronic structure of the material, improves its conductivity, structural stability, and reaction kinetics, but also weakens the dissolution of Mn2+. The optimized 0.1 % Fe-doped ZnMn 2 O 4 (0.1% Fe-ZnMn 2 O 4) has a capacity of 186.8 mAh g−1 after 250 charge-discharge cycles at 0.5 A g−1 and the discharge specific capacity reaches 121.5 mAh g−1 after 1200 long cycles at 1.0 A g−1. The theoretical calculation results show that doping causes the change of electronic state structure, accelerates the electron transfer rate, and improves the electrochemical performance and stability of the material. [ABSTRACT FROM AUTHOR]

In this study, two novel chemosensors containing dihydropyridine fragment namely; (2E, 2Eʹ)-1,1ʹ-(2,6-dimethyl-1,4-dihydropyridine-3,5-diyl)bis(3-(4-(dimethylamino)phenyl)prop-2-en-1-one) (1), (2E,2E',4E,4E')-1,1ʹ -(2,6-dimethyl-1,4-dihydropyridine-3,5-diyl)bis(5-(4-(dimethylamino)phenyl)penta-2,4-dien-1-one) (2) have been synthesized and characterized. The solvatochromic behavior was explored in different solvents of various polarities. The visual detection, as well as UV–Vis and fluorescence measurements were carried out to explore the colorimetric and optical sensing properties of the investigated chemosensors towards various metal ions such as Al3+, Cr3+, Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Mg2+, Hg2+ and Zn2+. The chemosensors 1 and 2 have strong detecting abilities, with excellent sensitivity and selectivity for Cu2+ and Fe3+, respectively, over the other metal ions. The chemosensors were totally reversible upon addition of EDTA to the formed complexes and displayed a turn on–off-on fluorescence response based on an effect of chelation-quenching fluorescence. The antioxidant activities of the investigated chemosensors were assessed. They were examined in-silico for their capacity to block the Akt signaling pathway, which is involved in cancer proliferation with interpreting their pharmacokinetics aspects. Furthermore, in-vitro antitumor evaluation against a panel of cancer cell lines for the investigated chemosensors has been examined. Conclusively, chemosensor 1 was more effective at scavenging free radicals and as an anticancer agent and could be exploited as a therapeutic candidate for cancer therapy than chemosensor 2 due to its potential inhibition of Akt protein. [ABSTRACT FROM AUTHOR]

Ubiquitin signalling and metal homeostasis play key roles in controlling several physiological cellular activities, including protein trafficking and degradation. While some relationships between these two biochemical pathways have started to surface, our knowledge of their interplay remains limited. Here, we employ a variety of techniques, such as circular dichroism, differential scanning calorimetry, pressure perturbation calorimetry, fluorescence emission, SDS-PAGE, and small-angle X-ray scattering (SAXS) to evaluate the impact of Cu2+ and Zn2+ ions on the structure and stability of K48 linked diubiquitin (K48-Ub2), a simple model for polyubiquitin chains. The SAXS analysis results show that the structure of the metal-free protein is similar to that observed when the protein is bound to the E2 conjugating enzyme, lending support to the idea that the structure of unanchored K48-linked ubiquitin chains is sufficient for identification by conjugating enzymes without the need for an induced fit mechanism. Our results indicate that K48-Ub2 can coordinate up to four metal ions with both copper and zinc ions inducing slight changes to the secondary structure of the protein. However, we noted significant distinctions in their impacts on protein stability and overall architecture. Specifically, Cu2+ ions resulted in a destabilization of the protein structure, which facilitated the formation of dimer aggregates. Next, we observed a shift in the conformational dynamics of K48-Ub2 toward less compact and more flexible states upon metal ion binding, with Zn2+ inducing a more significant effect than Cu2+ ions. Our structural modelling study demonstrates that both metal ions induced perturbations in the K48-Ub2 structure, leading to the separation of the two monomers thus inhibiting interactions with E2 enzymes. In conclusion, the findings from this study enhance our comprehension of the mechanisms underlying Ub chains recognition. Moreover, they strengthen the notion that drug discovery initiatives aimed at targeting metal-mediated disruptions in Ub signaling hold great potential for treating a wide range of diseases that stem from abnormal protein accumulation. [ABSTRACT FROM AUTHOR]

Zinc (Zn) metal, as a promising anode for aqueous zinc-ion batteries (AZIBs), has attracted much attention owing to its reasonable redox potential and fabulous theoretical capacity. Notwithstanding, Zn dendrites and side reactions generated during charging/discharging seriously inhibit the reversibility of Zn anode of AZIBs. Herein, ultra-long manganese dioxide (MnO 2) nanowires with low cost and easy synthesis have been designed as a high-efficiency zinc ion shunt to achieve uniform Zn deposition. The Zn coated with MnO 2 protection layer possesses good water wettability, high ionic conductivity (1.3 mS cm − 1) and low activation energy (38.2 kJ mol − 1). As a result, the Zn@MnO 2 ||Zn@MnO 2 symmetric cell exhibits an ultra-long lifespan over 3800 h at 0.5 mA cm−2/0.25 mAh cm−2; for the Zn@MnO 2 ||Zn@MnO 2 symmetric cell, the accumulative discharge capacity surpasses 1600 mAh cm − 2 and the depth of discharge (DOD) is 34.2% at the harsh conditions of 20 mA cm−2/20 mAh cm−2; and the average coulombic efficiency (CE) of the Zn//Cu@MnO 2 asymmetric cell achieves 99.6%. In addition, the Zn@MnO 2 //NVO full cell possesses an excellent reversible discharge capacity of 176.3 mAh g−1 after 1000 cycles at 2 A g−1. This investigation provides a useful reference for designing high-efficiency zinc ion shunt to realize highly reversible Zn anode for AZIBs. [ABSTRACT FROM AUTHOR]

The study of substances with antibacterial properties has expanded greatly in recent years. However, there are few reports about the antibacterial activity of Ag@MOFs and I2@MOFs. In this study, ZIF-7 was used to load iodine (I2@ZIF-7) and silver nanoparticles (Ag@ZIF-7). FT-IR spectroscopy, PXRD, ZP, SEM, TEM, TGA, and BET analysis were used to investigate the successful synthesis of the samples. I2@ZIF-7 and Ag@ZIF-7 showed prolonged release of I2 and Ag+ up to 11 days, in addition to Zn2+ cation release. Finally, S. aureus and E. coli bacteria were used to study the antibacterial activity of the samples. The results showed that the antibacterial activity increased in the samples containing iodine (I2@ZIF-7) and silver nanoparticles (Ag@ZIF-7). ZIF-7 has antibacterial components, zinc metal ions, as an antibacterial agent and a suitable ligand, along with iodine and silver, causing a synergistic effect, which was another reason for choosing ZIF-7. I2@ZIF-7 and Ag@ZIF-7 showed a certain amount of antibacterial substance release such as iodine and silver gradually and for a long time (for about 11 days). I2@ZIF-7 and Ag@ZIF-7 also showed better antibacterial activity than other reported Ag@MOFs and I2@MOFs. [ABSTRACT FROM AUTHOR]

The toxicity of metal ions on ecosystems has led to increasing amounts of research on their removal from wastewater. This paper presents the efficient application of a carbon magnetic nanocomposite as an adsorbent for the elimination of metal ions (copper, lead and zinc) from aqueous solutions. A Box–Behnken factorial design combined with the response surface methodology was conducted to investigate the effect and interactions of three variables on the pollutant removal process. Highly significant (p < 0.001) polynomial models were developed for each metal ion: the correlation coefficient was 0.99 for Cu(II) and Pb(II), and 0.96 for Zn(II) ion removal. The experimental data were in agreement and close to the theoretical results, which supports the applicability of the method. Working at the natural pH of the solutions, with a quantity of carbon magnetic nanocomposite of 1 g/L and a metal ions' concentration of 10 mg/L, for 240 min, removal efficiencies greater than 75% were obtained. The kinetic study indicated that a combination of kinetic models pseudo-second order and intraparticle diffusion were applied appropriately for copper, lead and zinc ion adsorption on carbon magnetic nanocomposite. The maximum adsorption capacities determined from the Langmuir isotherm model were 81.36, 83.54 and 57.11 mg/g for copper, lead and zinc ions. The average removal efficiency for five adsorption–desorption cycles was 82.21% for Cu(II), 84.50% for Pb(II) and 72.68% for Zn(II). The high adsorption capacities of metal ions, in a short time, as well as the easy separation of the nanocomposite from the solution, support the applicability of the magnetic carbon nanocomposite for wastewater treatment. [ABSTRACT FROM AUTHOR]

Metal ions are essential cofactors for many proteins and play a crucial role in many applications such as enzyme design or design of protein-protein interactions because they are biologically abundant, tether to the protein using strong interactions, and have favorable catalytic properties. Computational design of metalloproteins is however hampered by the complex electronic structure of many biologically relevant metals such as zinc. In this work, we develop two tools - Metal3D (based on 3D convolutional neural networks) and Metal1D (solely based on geometric criteria) to improve the location prediction of zinc ions in protein structures. Comparison with other currently available tools shows that Metal3D is the most accurate zinc ion location predictor to date with predictions within 0.70 ± 0.64 Å of experimental locations. Metal3D outputs a confidence metric for each predicted site and works on proteins with few homologes in the protein data bank. Metal3D predicts a global zinc density that can be used for annotation of computationally predicted structures and a per residue zinc density that can be used in protein design workflows. Currently trained on zinc, the framework of Metal3D is readily extensible to other metals by modifying the training data. Zinc is an essential metal for many proteins. Here, the authors propose a model based on 3D convolutional networks to predict the location of zinc in experimental and computationally predicted structures within a framework readily extensible to other metals. [ABSTRACT FROM AUTHOR]

The excellence of MXene electrode material for high performance battery and supercapacitor devices represents immense possibility to construct MXene‐based metal ion capacitors (MICs) with a high energy/power density and long cyclic life. Various reports indicate that the MXene and its composites/heterostructures can be a suitable anode material to assemble MICs in non‐aqueous/aqueous electrolytes. The pillaring of MXenes with Sn4+, Fe2O3, TiO2, Fe3O4/C, SnO2, NaNbO3, MoS2, CNTs, graphene, etc. effectively alleviates restacking of nanosheets and provides large interlayer spacing as well as additional active sites. Formation of three‐dimensional network with porous structures and heteroatom doping are also advantageous for high performance electrode materials. Results indicate that the MICs can achieve a high energy density (up to 241 Wh kg−1) like rechargeable battery, a high power density (up to 25,000 W kg−1) like supercapacitor, and a satisfactory cyclic stability. This article reviews state‐of‐the art MXene‐based anode materials for various MICs. After a brief introduction about the MICs, its storage principle, historical background, and insights of the MXene synthesis, property, and storage mechanism, the article summarizes/evaluates the electrochemical performance of various MICs assembled by the MXene‐based anode materials. Finally, we outline challenges/future prospects of the MICs using MXene‐based anode materials. [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion batteries (AZIBs) and, in particular, Zn//MnO2 rechargeable batteries have attracted great attention due to the abundant natural resources of zinc and manganese, low cost, environmental friendliness, and high operating voltage. Among the various ways to improve the electrochemical performance of MnO2-based cathodes, the development of MnO2 cathodes doped with metal ions or composites of MnO2 with conducting polymers has shown such advantages as increasing the specific capacity and cycling stability. This mini-review focuses on the strategies to improve the electrochemical performance of manganese-based cathodes of AZIBs. [ABSTRACT FROM AUTHOR]

Human cleavage and polyadenylation specificity factor (CPSF)73 (also known as CPSF3) is the endoribonuclease that catalyzes the cleavage reaction for the 30-end processing of premRNAs. The active site of CPSF73 is located at the interface between a metallo-ß-lactamase domain and a ß-CASP domain. Two metal ions are coordinated by conserved residues, five His and two Asp, in the active site, and they are critical for the nuclease reaction. The metal ions have long been thought to be zinc ions, but their exact identity has not been examined. Here we present evidence from inductively coupled plasma mass spectrometry and X-ray diffraction analyses that a mixture of metal ions, including Fe, Zn, and Mn, is present in the active site of CPSF73. The abundance of the various metal ions is different in samples prepared from different expression hosts. Zinc is present at less than 20% abundance in a sample expressed in insect cells, but the sample is active in cleaving a pre-mRNA substrate in a reconstituted canonical 30-end processing machinery. Zinc is present at 75% abundance in a sample expressed in human cells, which has comparable endonuclease activity. We also observe a mixture of metal ions in the active site of the CPSF73 homolog INTS11, the endonuclease for Integrator. Taken together, our results provide further insights into the role of metal ions in the activity of CPSF73 and INTS11 for RNA 30-end processing. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMPs) are essential components of innate immunity across all species. AMPs have become the focus of attention in recent years, as scientists are addressing antibiotic resistance, a public health crisis that has reached epidemic proportions. This family of peptides represents a promising alternative to current antibiotics due to their broad-spectrum antimicrobial activity and tendency to avoid resistance development. A subfamily of AMPs interacts with metal ions to potentiate antimicrobial effectiveness, and, as such, they have been termed metalloAMPs. In this work, we review the scientific literature on metalloAMPs that enhance their antimicrobial efficacy when combined with the essential metal ion zinc(II). Beyond the role played by Zn(II) as a cofactor in different systems, it is well-known that this metal ion plays an important role in innate immunity. Here, we classify the different types of synergistic interactions between AMPs and Zn(II) into three distinct classes. By better understanding how each class of metalloAMPs uses Zn(II) to potentiate its activity, researchers can begin to exploit these interactions in the development of new antimicrobial agents and accelerate their use as therapeutics. [ABSTRACT FROM AUTHOR]

In aqueous zinc ion batteries (ZIBs), the H+ intercalation possesses superior electrochemical kinetics with excellent rate capability, however, precisely modulating H+ intercalation has been still challenging. Herein, a critical modification of pre‐intercalating metal ions in the MnO2 interlayer (M−MnO2) with controllable p‐band center (ϵp) of O is reported to modulate the H+ intercalation. The modulation of metal‐O bond type and covalency degree on the average charge of O atom results in optimized ϵp and H+ adsorption energy for M−MnO2, thus promoting the balance between H+ adsorption and desorption, which plays a determinant role on H+ intercalation. The optimized Cu−MnO2 delivers superior rate capability with the capacity of 153 mAh g−1 at a high rate of 3 A g−1 after 1000 cycles. This work demonstrates that ϵp could be a significant descriptor for H+ intercalation, and tuning ϵp effectively increases H+ intercalation contribution with excellent rate capability in ZIBs. [ABSTRACT FROM AUTHOR]

Soil microbial fuel cells (SMFCs) are an innovative device for soil-powered biosensors. However, the traditional SMFC sensors relied on anodic biosensing which might be unstable for long-term and continuous monitoring of toxic pollutants. Here, a carbon-felt-based cathodic SMFC biosensor was developed and applied for soil-powered long-term sensing of heavy metal ions. The SMFC-based biosensor generated output voltage about 400 mV with the external load of 1000 Ω. Upon the injection of metal ions, the voltage of the SMFC was increased sharply and quickly reached a stable output within 2~5 min. The metal ions of Cd2+, Zn2+, Pb2+, or Hg2+ ranging from 0.5 to 30 mg/L could be quantified by using this SMFC biosensor. As the anode was immersed in the deep soil, this SMFC-based biosensor was able to monitor efficiently for four months under repeated metal ions detection without significant decrease on the output voltage. This finding demonstrated the clear potential of the cathodic SMFC biosensor, which can be further implemented as a low-cost self-powered biosensor. [ABSTRACT FROM AUTHOR]

The corrosion of zinc anode significantly undermines the stability of aqueous zinc-based energy storage devices (ZnESDs), potentially leading to cell failure even explosions. In this study, we mixed a high concentration electrolyte (21 m LiTFSI) with a conventional 2 m Zn(OTF) 2 electrolyte to highly reduce the activity of solvent water, which can greatly suppress the corrosion of zinc anode at room temperature and high temperatures. We systematically studied the phenomenon of ZnWiS inhibiting zinc anode corrosion at different temperatures and investigated its principle through experiments and theoretical calculations. As a result, the Zn||Zn symmetric cells demonstrated remarkable stability, sustaining over 3642 h at room temperature and over 112 h at 80 °C. Moreover, the as assembled aqueous zinc ion hybrid supercapacitors (ZHSC) also exhibited excellent cycling stability for over 5220 h at room temperature and over 165 h at 80 °C. In contrast, ZHSC assembled with 2 m Zn(OTF) 2 can only cycle 80 h at room temperature, and 9 h at 80 °C. These findings confirm that reducing water activity in the electrolyte effectively contributes to achieving highly stable aqueous ZnESDs, and the universality of this strategy offering promise for its application in various aqueous metal ion energy storage devices. [Display omitted] • Reducing water activity could tremendously inhibit the zinc anodes corrosion. • The assembled ZHSCs can cycle for over seven months at room temperature. • The assembled ZHSCs can cycle for 165 h at 80 °C. [ABSTRACT FROM AUTHOR]

In this study, we developed a novel covalent organic framework (COF) material, termed RuCOFs, specifically designed and synthesized for electrochemiluminescence (ECL) sensor applications. RuCOFs are based on the classic ECL emitter Ru(dcbpy) 3 2+, ingeniously integrating 4,4′,4''-(1,3,5-triazine-2,4,6-triyl) triphenylamine (TAPT) with [2,2′-bipyridine]-5,5′-diamine (BPYDA), forming a structure with a high specific surface area. This configuration not only significantly enhances the stability of the ECL signal but also provides ideal N,N′-bipyridine chelating sites for efficient metal ion recognition. Utilizing Ru(dcbpy) 3 2+-functionalized COF (RuCOFs), a novel dual-function ECL sensor was developed, achieving high sensitivity and selectivity in detecting mercury (Hg2⁺) and zinc (Zn2⁺) ions. Experimental results indicate that Hg2⁺ significantly quenches the ECL signal, while Zn2⁺ markedly enhances it, with detection limits of 4.71 nM for Hg2⁺ and 6.57 nM for Zn2⁺ across a wide linear response range from 1 μM to 1 nM. This research not only demonstrates the significant advantages of COF-based ECL sensing platforms in tracking environmental metal ions but also opens new possibilities for environmental monitoring. [Display omitted] • Developed a highly sensitive ECL sensor for detecting Hg2⁺ and Zn2⁺. • Achieved detection limits of 4.71 nM for Hg2⁺ and 6.57 nM for Zn2⁺. • Demonstrated signal suppression for Hg2⁺ and activation for Zn2⁺, enabling efficient environmental monitoring. [ABSTRACT FROM AUTHOR]

The development of satisfactory cathodes plays a key role in the widespread utilization of aqueous zinc ion batteries. Cathode materials with high specific capacity and long cycling life are still urgently needed for aqueous zinc ion batteries. Herein, a new cathode material VO(OH) 2 is synthesized by a facile room-temperature precipitation approach, and its electrochemical characteristics and structural evolution process are investigated. Benefiting from its intrinsic electrochemical activity, the VO(OH) 2 cathode exhibits a remarkable specific capacity of 488 mAh g−1 at 0.1 A g−1, retains a high capacity of 219.1 mAh g−1 at the increased current density of 10 A g−1, and provides a maximum energy density of 439.2 Wh kg−1. In addition, when subjected to a 12,000 cycles charge/discharge test at 10 A g−1, the cathode retains a capacity of 185.8 mAh g−1, highlighting durable cycling performance. The structural evolution analysis reveals that of VO(OH) 2 cathode may be in-situ transformed to an amorphous vanadium oxide V 2 O 5-x in the first charging process, which could reversibly intercalate/deintercalate zinc ions. This research supplies a promising cathode material for aqueous zinc ion batteries and enhances understanding of vanadium oxyhydroxide in metal ion storage. [Display omitted] • VO(OH) 2 was applied as cathode materials in AZIBs for the first time. • It was synthesized by a simple precipitation approach. • It exhibits 488 mAh/g at 0.1 A/g and retained 185.8 after cycling at 10 A/g for 12,000 times. • Its kinetics and structural evolution have been revealed. [ABSTRACT FROM AUTHOR]

While treating zinc-containing wastewater, recovering zinc for reuse as a secondary resource has significant environmental and economic benefits. Herein, based on the alkali-activated tourmaline tailings geopolymers (TTG) after adsorption of zinc ions (Zn (II)), a series of new composites with in-situ construction ZnS nanoparticles on TTG (ZnS/TTG) were synthesized, and used as photocatalysts for the photodegradation of tetracycline hydrochloride (TCH) in solution. Specifically, ZnS nanoparticles were uniformly and stably distributed in the layered structure of TTG, interweaving with each other to generate an interfacial electric field, which could induce more photocarrier generation. Meanwhile, TTG acted as an electron acceptor to accelerate the electron transfer at the interface, thus enhancing the photodegradation activity for TCH. The active radical quenching experiments combined with the ESR indicated that the active species produced during the photocatalytic degradation of TCH by ZnS/TTG composites were •O 2 − and photogenerated h+. When the initial concentration of Zn (II) was 60 mg/L, the synthesized 60-ZnS/TTG composites (0.5 g/L) reached 91.53% degradation efficiency of TCH (10 mg/L) at pH = 6. Furthermore, the possible pathways and mechanism of 60-ZnS/TTG composites photodegraded TCH were revealed with the aid of degraded intermediates. This report not only proposed valuable references for reusing heavy metal ions and removing TCH from wastewater, but also provided promising ideas for realizing the conversion of used adsorbents into high-efficiency photocatalysts. [Display omitted] • Nanoscale ZnS was constructed on the surface of TTG while treating Zn (II)-containing wastewater. • The functional groups on the TTG effectively improved the agglomeration and dispersion of ZnS nanoparticle. • This report provided enlightening ideas for the conversion of used adsorbents into photocatalysts. [ABSTRACT FROM AUTHOR]

The electrochemical performance of the cathode material is influenced by its structure, including morphology, pore size, specific surface area, layer spacing, impurity content, and species. Each of these factors plays a distinct role in the energy storage process of the electrode. The purpose of this review is not only to provide the relationship between the structure and mechanism of cathode materials, but also to provide directional guidance for optimizing electrochemical performance of the materials. [Display omitted] • Critically reviewing the applications of various cathode materials in MIHCs (Li, Na, K and Zn). • Discussing the relationship between material structure and energy storage mechanism. • Summarizing the methods of optimizing electrochemical properties of cathode materials. Metal ion hybrid capacitors (MIHCs) consist of both capacitance-type electrodes and battery-type electrodes, thereby combining the advantages of metal ion batteries and supercapacitors. Nevertheless, the disparity between the specific capacity and rate performance of the cathode and anode materials suggests that the current performance of MIHCs does not meet practical requirements. The performance of MIHCs is affected by the type, composition, and morphology of the cathode material, affirming their essential role as critical components. Therefore, there is a need to concentrate on and discuss the electrochemical properties of electrode materials, as well as strategies aimed at enhancing their electrochemical performance. This article introduces the composition, types, and energy storage mechanisms of MIHCs. Subsequently, a review is conducted on the cathode materials used in lithium, sodium, potassium, and zinc ion capacitors, with emphasis on their physical and chemical properties and the resulting electrochemical performance. Moreover, a comprehensive investigation is conducted to explore effective strategies for enhancing the electrochemical properties of materials, incorporating a substantial number of theoretical calculations and experimental results. Finally, this review provides valuable suggestions for the development and large-scale production of cathode electrode materials for MIHCs (Li+, Na+, K+, and Zn2+), addressing current issues and proposing potential research directions. [ABSTRACT FROM AUTHOR]

The adsorbent ability of Al2O3 nanoparticles (ANPs) was examined to remove Cd2+ and Zn2+ from aqueous solution. The sorption of Cd2+ and Zn2+ on ANPs as a function of pH, ionic strength (IS), humic acid (HA), contact time, foreign ions and the temperature were investigated. It was observed that physico-chemical factors (pH and ionic strength) strongly affect the sorption of Cd2+ and Zn2+ on ANPs. Comparatively, the sorption of Cd2+ and Zn2+ dominated by surface complexation of the outer sphere at low pH values (pH < 8.0), while surface complexation of the inner sphere was the major sorption mechanism at elevated pH values (pH > 8.0). The maximum sorption capacity of Cd2+ and Zn2+ on ANPs calculated from the Langmuir model was 8.40 and 9.00 mg g–1 respectively at 303 K, exhibiting higher efficiency for Zn2+ sorption than Cd2+.The thermodynamic parameters (∆H0, ∆S0 and ∆G0) showed that the adsorption of Cd2+ and Zn2+ was endothermic and spontaneous. This investigation exhibited that ANP is an efficient, inexpensive process and thereby reasonable technology for the elimination of metal ions from the contaminated aqueous source. [ABSTRACT FROM AUTHOR]

[Display omitted] Aqueous zinc-ions batteries with low cost, reliable safety, high theoretical specific capacity and eco-friendliness have captured conspicuous attention in large-scale energy storage. However, the developed cathodes often suffer from low electrical conductivity and sluggish Zn2+ diffusion kinetics, which severely hampers the development of aqueous zinc-ions batteries. Herein, we successfully prepare Mg/PANI/V 2 O 5 •nH 2 O (MPVO) nanosheets through conducting polymers (polyaniline) and metal ions (Mg2+) co-intercalated strategy and systematically explore its electrochemical performance as cathode materials for aqueous zinc-ion batteries. Benefitting from the synergistic effect of polyaniline and Mg2+ co-intercalated, the MPVO exhibits larger interlayer spacing and higher electrical conductivity than the single guest intercalation, which significantly enhances the electrochemical kinetics. As a consequence, the MPVO cathodes deliver superior specific capacity, rate capability and long-term cycling performance. Moreover, multiple characterizations and theoretical calculations are executed to expound the relevant mechanism. Therefore, this work provides a novel thought for the design of high-performance cathode materials for aqueous ZIBs. [ABSTRACT FROM AUTHOR]

Determination of metal ions such as zinc in solution remains an important task in analytical and biological chemistry. We describe a novel zinc ion biosensing approach using a carbonic anhydrase–Oplophorus luciferase fusion protein that employs bioluminescence resonance energy transfer (BRET) to transduce the level of free zinc as a ratio of emission intensities in the blue and orange portions of the spectrum. In addition to high sensitivity (below nanomolar levels) and selectivity, this approach allows both quantitative determination of "free" zinc ion (also termed "mobile" or "labile") using bioluminescence ratios and determination of the presence of the ion above a threshold simply by the change in color of bioluminescence, without an instrument. The carbonic anhydrase metal ion sensing platform offers well-established flexibility in sensitivity, selectivity, and response kinetics. Finally, bioluminescence labeling has proven an effective approach for molecular imaging in vivo since no exciting light is required; the expressible nature of this sensor offers the prospect of imaging zinc fluxes in vivo. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Na 0.23 (VO 1− x) 3 (PO 4) 2.14 nanosheets are simply prepared. • The cathode delivers a high specific discharge capacity of 75.3 mAh g−1 at 0.1 A g−1. • A high capacity retention of Na 0.23 (VO 1− x) 3 (PO 4) 2.14 cathode is obtained. • The zinc storage mechanism is discussed on basis of ex situ XRD and XPS. At present, layered vanadium–oxygen structures have attracted wide attention for multivalent metal ion storage, especially in aqueous zinc-ion batteries (AZIBs), due to the attractive layered structure and large specific capacity based on V5+/V3+ double electron transfer. However, in addition to a large specific capacity, a high output voltage is necessary to achieve a high specific energy density. Vanadium oxide and vanadate usually feature low working voltages, serious structural degradation and limited practical. To alleviate these problems, some cathode modification strategies have been proposed that improve the operating voltage, structural stability and diffusion kinetics of multivalent metal ions. In this paper, vanadyl phosphate (Na y (VO 1− x) 3 (PO 4) 2) nanosheets preintercalated with sodium ions and modified with oxygen vacancies were prepared via a facile one-step liquid phase treatment. The Na y (VO 1− x) 3 (PO 4) 2 nanosheet cathode for AZIBs delivered a high specific capacity of 75.3 mAh g−1 at 0.1 A g−1 and retained 27.5 mAh g−1 after 4000 cycles at 2 A g−1. Subsequently, the as-prepared Na y (VO 1− x) 3 (PO 4) 2 nanosheets were physically and electrochemically characterized, and a possible mechanism of Zn2+ insertion/extraction and structural decomposition was proposed based on ex situ XRD and XPS characterizations. Our work provides a simple method for simultaneously introducing sodium ion preintercalation and oxygen vacancies into vanadyl phosphate structures, and provides some insights into the zinc storage mechanism. [ABSTRACT FROM AUTHOR]

Schiff bases are in the field of medicinal and material chemistry for a long time. There are several advancements from time to time towards facile synthesis and potential applications. As medicines they have been applied as organic molecules as well as their metal complexes. The activities of metal complexes have been found to increase due to increase lipophilicity in comparison to the corresponding free ligand. Besides simple coordination compounds they have been applied as ionic liquid (IL)- supported and IL-tagged species with far enhanced efficiency. Among metal complexes recent advancement deals with photodynamic therapy to treat a number of tumors with fewer side effects. Schiff bases are efficient ligands and their complexes with almost all metal ions are reported. This mini-review article deals with complexes of Schiff bases with biologically compatible metal ions, Co(II), Cu(II), Zn(II), Pd(II), Ag(I), Pt(II) and their potential uses to combat cancerous cells. Strong hopes are associated with photodynamic therapy and IL-tagged and IL-supported Schiff bases and their complexes. [ABSTRACT FROM AUTHOR]

The bioavailability of copper (Cu) in human cells may depend on a complex interplay with zinc (Zn) ions. We investigated the ability of the Zn ion to target the human Cu-chaperone Atox1, a small cytosolic protein capable of anchoring Cu(I), by a conserved surface-exposed Cys-X-X-Cys (CXXC) motif, and deliver it to Cu-transporting ATPases in the trans-Golgi network. The crystal structure of Atox1 loaded with Zn displays the metal ion bridging the CXXC motifs of two Atox1 molecules in a homodimer. The identity and location of the Zn ion were confirmed through the anomalous scattering of the metal by collecting X-ray diffraction data near the Zn K-edge. Furthermore, soaking experiments of the Zn-loaded Atox1 crystals with a strong chelating agent, such as EDTA, caused only limited removal of the metal ion from the tetrahedral coordination cage, suggesting a potential role of Atox1 in Zn metabolism and, more generally, that Cu and Zn transport mechanisms could be interlocked in human cells. [ABSTRACT FROM AUTHOR]

K+ and Al3+ as the dual metal ions are uniformly pre-intercalated into the framework and the interlayer of δ-MnO 2 by hydrothermal method. The energy storage mechanism of δ-MnO 2 is the combination of dissolution/deposition and H+/Zn2+ co-insertion/co-extraction. [Display omitted] Layered δ-MnO 2 is a promising cathode material for aqueous zinc ion batteries (AZIBs) due to its high theoretical capacity, high operating voltage and low cost. However, the dissolution of MnO 2 and the disproportionation of Mn3+ will lead to irreversible reaction and serious structural degradation of the material during cycling process. In this work, the Al3+ pre-intercalated K 0.27 MnO 2 ·0.54H 2 O was prepared by a one-step hydrothermal method with citric acid as the complexing agent and weak reducing agent. Based on the pillars of bimetallic ions K+, Al3+ and water, the framework and interlayer of δ-MnO 2 is stabilized. Besides, a certain amount of Al3+ facilitates the increase of crystal water compared with the pure K 0.27 MnO 2 ·0.54H 2 O, which is not only conducive to promote the construction of porous and loose 3D morphology, but also beneficial to improve the stability of layered structure and accelerate the migration rate of zinc ions. Contributed to the dissolution/deposition reaction mechanism combined with H+/Zn2+ co-insertion/co-extraction mechanism, it has achieved the high capacity with the maximum reversible specific capacity of 269.5 mAh g−1 at 0.5 A g−1 and excellent stability with 205.8 mAh g−1 even after 300 cycles in Zn//Al-KMO battery. [ABSTRACT FROM AUTHOR]

A novel polyaniline-modified CNT and graphene-based nanocomposite (2.32–7.34 nm) was prepared and characterized by spectroscopic methods. The specific surface area was 176 m2/g with 0.232 cm3/g as the specific pore volume. The nanocomposite was used to remove zinc and lead metal ions from water; showing a high removal capacity of 346 and 581 mg/g at pH 6.5. The data followed pseudo-second-order, intraparticle diffusion and Elovich models. Besides this, the experimental values obeyed Langmuir and Temkin isotherms. The results confirmed that the removal of lead and zinc ions occurred in a mixed mode, that is, diffusion absorption and ion exchange between the heterogeneous surface of the sorbent containing active adsorption centers and the solution containing metal ions. The enthalpy values were 149.9 and 158.6 J.mol−1K−1 for zinc and lead metal ions. The negative values of free energies were in the range of −4.97 to −26.3 kJ/mol. These values indicated an endothermic spontaneous removal of metal ions from water. The reported method is useful to remove the zinc and lead metal ions in any water body due to the high removal capacity of nanocomposite at natural pH of 6.5. Moreover, a low dose of 0.005 g per 30 mL made this method economical. Furthermore, a low contact time of 15 min made this method applicable to the removal of the reported metal ions from water in a short time. Briefly, the reported method is highly economical, nature-friendly and fast and can be used to remove the reported metal ions from any water resource. [ABSTRACT FROM AUTHOR]

Electron donor–acceptor (EDA) complexes are characterized by charge-transfer (CT) processes between electron-rich and electron-poor counterparts, typically resulting in a new absorption band at a higher wavelength. In this paper, we report a series of novel 2,6-di(imino)pyridine ligands with different electron-rich aromatic substituents and their 1:2 (metal/ligand) complexes with zinc(II) in which the formation of a CT species is promoted by the metal ion coordination. The absorption properties of these complexes were studied, showing the presence of a CT absorption band only in the case of aromatic substituents with donor groups. The nature of EDA interaction was confirmed by crystallographic studies, which disclose the electron-poor and electron-rich moieties involved in the CT process. These moieties mutually belong to both the ligands and are forced into a favorable spatial arrangement by the coordinative preferences of the metal ion. [ABSTRACT FROM AUTHOR]

Pyrene linked‐coumarin based fluorescent chemosensors L1 and L2 are utilized for the selective detection of Cu2+ and Zn2+ ions, respectively. Both chemosensors differed by a methylene spacer that connects the coumarin and pyrene rings through an imine group. The inclusion of methylene spacer dramatically changed the detection profiles of two chemosensors. While L1 showed fluorescence "turn‐off" response towards the Cu2+ ion; L2 showed "turn‐on" emission enhancement with the Zn2+ ion. Both chemosensors illustrated nano‐molar detection limits and were selective even in the presence of other competing metal ions. The 1 : 1 stoichiometry between a chemosensor and Cu2+/Zn2+ ion was supported by the binding studies, Job's plot, NMR spectral titrations, mass spectra and density functional theory (DFT) studies. The detection ability of both chemosensors was utilized by fabricating the filter paper test‐strips as well as polystyrene films for quick and visual monitoring of these ions in different water samples. Chemosensor L2 was further utilized for the "turn‐on" detection of Zn2+ ion in HepG2 cells whereas solution generated L2‐Zn species functioned as a secondary chemosensor for the detection of cystine, an important amino acid. [ABSTRACT FROM AUTHOR]