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The quest for lowering energy consumption during thin film growth by magnetron sputtering techniques becomes of particular importance in view of sustainable development goals. As large fraction of the process energy is consumed in substrate heating for the purpose of providing high adatom mobility necessary to grow dense films, the most straightforward strategy toward more environment-friendly processing is to find alternatives to thermally activated surface diffusion. One possibility is offered by high mass metal ion irradiation of the growing film surface, which has been recently shown to be very effective in densification of transition metal nitride layers grown with no external heating, such that Zone 2 microstructures of the structure-zone model are obtained in the substrate temperature Ts range otherwise typical for Zone 1 growth. The large mass difference between the incident ion and the atoms constituting the film results in effective creation of low energy recoils, which leads to film densification at low Ts. Due to their high mass, metal ions become incorporated at lattice sites beyond the near-surface region of intense recoil generation leading to further densification, while preventing the buildup of residual stress. The practical implementation of this technique discussed in this Perspective employs heavy metal targets operating in the high-power impulse magnetron sputtering (HiPIMS) mode to provide periodic metal-ion fluxes that are accelerated in the electric field of the substrate to irradiate layers deposited from direct current magnetron sputtering (DCMS) sources. A key feature of this hybrid HiPIMS/DCMS configuration is the substrate bias that is synchronized with heavy metal ion fluxes for selective control of their energy and momentum. As a consequence, the major fraction of process energy is used at sputtering sources and for film densification, rather than for heating of the entire vacuum vessel. Model material systems include TiN and metastable NaCl-structure Ti1−yAlyN films, which are well-known for challenges in stoichiometry and phase stability control, respectively, and are of high relevance for industrial applications. This Perspective provides a comprehensive overview of the novel film growth method. After presenting basic concepts, time-resolved measurements of ion fluxes at the substrate plane, essential for selective control of metal ion energy and momentum, are discussed. The role of metal ion mass, energy, momentum, and concentration is described in more detail. As some applications require substrate rotation for conformal coating, a section is devoted to the related complexity in the implementation of metal-ion-synchronized growth under industrial conditions. [ABSTRACT FROM AUTHOR]

Intermolecular Coulombic decay or electron transfer-mediated decay are the autoionization processes through which a molecule can relax. This relaxation is only possible if the inner valence's ionization potential (IP) exceeds the system's double ionization potential (DIP). To study the effects of charge and solvation shell, we have calculated the IP, DIP values, and lifetime of Na-2s and Mg-2s temporary bound states in various optimized structures of Na+-(H2O)n and Mg2+-(H2O)n (n = 1–5) micro-solvated clusters, where n water molecules are distributed in a way that some are directly bound to the metal ion and the rest to the water molecules. The first and second solvation shells are the names for the former and the latter water-binding positions, respectively. For a given n, the lifetime of decaying states is longer when water molecules are in the second solvation shell. We found that the Mg-2p state can decay for all n values in Mg2+-(H2O)n clusters, whereas the Na-2p state's decay is possible for n ≥ 2 in Na+-(H2O)n clusters. Our findings highlight the influence of metal ions' charge, different solvation shell structures, and the number of water molecules on the decay rate. These systems are relevant to the human body, which makes this study significant. [ABSTRACT FROM AUTHOR]

We present a Raman scattering spectroscopic study of boron imidazolate metal-organic frameworks (BIFs) with three different magnetic metal ions and one non-magnetic in a wide frequency range from 25 to 1700 cm−1, which covers local vibrations of the imidazolate linkers as well as collective lattice vibrations. We show that the spectral region above 800 cm−1 belongs to the local vibrations of the linkers, which have the same frequencies for the studied BIFs without any dependence on the structure of the BIFs and are easily interpreted based on the spectra of imidazolate linkers. In contrast, collective lattice vibrations, observed below 100 cm−1, show a distinction between cage and two-dimensional BIFs structures, with a weak dependence on the metal node. We identify the range of vibrations around 200 cm−1, which are distinct for each metal-organic framework, depending on a metal node. Our work demonstrates the energy hierarchy in the vibrational response of BIFs. [ABSTRACT FROM AUTHOR]

Wheat germ protein (WGP) was extracted from wheat germ powder by alkali dissolution and acid precipitation, and WGP was modified by microwave and metal ion treatment. The functional properties, structure, and molecular mass of WGP before and after modification were determined. The results showed that compared with the control group, the solubility of WGP was increased by 86.61% after the combined treatment, the water-holding capacity (WHC) and oil-holding capacity (OHC) were increased by 22.86% and 82.16%, the emulsifying capacity, emulsion stability and foaming capacity were increased by 120.90%, 15.64% and 116.91%, respectively, and the foaming stability was reduced. The results of Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that there was no significant change in the molecular mass of WGP after the combined treatment, while the structure became looser, and the secondary structure exhibited a trend toward a disordered state, mainly manifested as an increase of β-turn and random coil. The combined treatment was superior to either microwave or metal ion treatment alone in improving the functional characteristics of WGP. The combined treatment with microwave and metal ions offers WGP with good functional characteristics, thereby providing WGP the potential to be developed into a new functional food.

Abstract Due to the non-degradable and persistent nature of metal ions in the environment, they are released into water bodies, where they accumulate in fish. In order to assess pollution in fish, the enzyme, glucose 6-phosphate dehydrogenase (G6PD), has been employed as a biomarker due to sensitivity to various ions. This study investigates the kinetic properties of the G6PD enzyme in yellow catfish (Pelteobagrus fulvidraco), and analyzes the effects of these metal ions on the G6PD enzyme activity in the ovarian cell line (CCO) of channel catfish (Ictalurus punctatus). IC50 values and inhibition types of G6PD were determined in the metal ions Cu2+, Al3+, Zn2+, and Cd2+. While, the inhibition types of Cu2+ and Al3+ were the competitive inhibition, Zn2+ and Cd2+ were the linear mixed noncompetitive and linear mixed competitive, respectively. In vitro experiments revealed an inverse correlation between G6PD activity and metal ion concentration, mRNA levels and enzyme activity of G6PD increased at the lower metal ion concentration and decreased at the higher concentration. Our findings suggest that metal ions pose a significant threat to G6PD activity even at low concentrations, potentially playing a crucial role in the toxicity mechanism of metal ion pollution. This information contributes to the development of a biomonitoring tool for assessing metal ion contamination in aquatic species.

Nutrient availability in hydroponic solutions must be accurately monitored to maintain crop productivity; however, few cost-effective, accurate, real-time, and long-term monitoring technologies have been developed. In this study, we describe the development and application of cation-/anion-exchange chromatography with a neutral eluent (20-mmol/L sodium formate, pH 7.87) for the simultaneous separation (within 50 min) of ionic nutrients, including K+, NH4+, NO2−, NO3−, and phosphate ion, in a hydroponic fertilizer solution. Using the neutral eluent avoided degradation of the separation column during precipitation of metal ion species, such as hydroxides, with an alkaline eluent and oxidation of NO2− to NO3− with an acidic eluent. The suitability of the current method for monitoring ionic components in a hydroponic fertilizer solution was confirmed. Based on our data, we propose a controlled fertilizer strategy to optimize fertilizer consumption and reduce the chemical load of drained fertilizer solutions. [ABSTRACT FROM AUTHOR]

The present investigation demonstrates a simple, sensitive and selective colorimetric probe for the detection of Hg2+ in milk samples employing redox interaction of Hg2+ ions with citrate‐stabilised silver nanoparticles, inducing colour change from yellow to colourless. Milk samples were pretreated by ultrasound assistance in acidic media. The detection limit (LOD) was 6.17 ppb using UV–Visible spectrophotometer with linear correlation (R2 = 0.9901) at 10–2000 ppb solution of Hg2+ ions. Developed probe was highly selective to Hg2+ over different interfering metal ions and can be effectively employed to identify Hg2+ in milk samples. [ABSTRACT FROM AUTHOR]

A2B2O7 oxides comprise four subcrystalline phase structures, which include the layered perovskite, pyrochlore, disordered defect fluorite, and rare‐earth C‐type structures. Herein, a series of A2B2O7 oxides have been synthesized using simple methods, and the X‐ray diffraction (XRD) and Raman spectroscopic characteristics of their subcrystalline phase structures are systematically summarized. It was found that the rA/rB ratio can be used to correctly determine the subcrystalline phase structure of the A2B2O7 oxides when the A‐site ions are rare‐earth ions. Although the A‐site ions are the main‐group metal ions, the rA/rB ratio cannot be used to accurately determine probably due to f electrons. Raman spectroscopy proves to be the most effective method for determining the subcrystalline phase structure, which is followed by XRD. The characteristic Raman spectral bands of disordered defect fluorites are closely related to their B‐site ion oxides with fluorite phase structures. For these A2B2O7 oxides with rA/rB ratios located at the edge value possessing the same elemental composition, different subcrystalline phase structures have been prepared by adopting different synthesis methods and calcination temperatures. The crystal phase of A2B2O7 oxides comprising two types of subcrystalline structures with a lower disorder degree is more stable at high temperatures. [ABSTRACT FROM AUTHOR]

L / D -Phenylglycine amphiphiles and metal ions with peroxidase-like activity self-assembled into chiral nanoribbons, which act as efficient chiral supramolecular nanozymes for catalyzing the 3,4-dihydroxy- L / D -phenylalanine (L / D -DOPA) oxidation reactions. The catalytic efficiency and enantioselectivity are dominated by the chirality transfer and the synergistic effect between the metal ions and chiral nanoribbons. [ABSTRACT FROM AUTHOR]

Heavy metal ions such as mercury (Hg), copper (Cu), and cadmium (Cd) pose significant threats to ecosystems and human health due to their toxicity and bioaccumulation potential. With growing environmental concerns over heavy metal ion pollution, there is an urgent need to develop efficient detection methods for safeguarding public health and the environment. Various materials, including polymers, nanomaterials, and porous substances, have been used for heavy metal ion detection and have shown promising performance for different scenarios. However, each of these materials has certain limitations as probes. Metal halide perovskites (MHPs), known for their exceptional optoelectronic properties and high structural and chemical tunability, have gained great attention in applications such as photovoltaics and LEDs. Yet, their potential as metal ion probes remains rarely explored. This review assesses MHPs as prospective materials for heavy metal ion detection, taking their structure, chemical properties, and responses to external stimuli into consideration. Three key detection mechanisms—cation exchange (CE), electron transfer (ET), and fluorescence resonance energy transfer (FRET), are explored to understand how metal ions trigger fluorescence changes on perovskites, enabling their detection. Finally, current avenues of developing perovskite probes are discussed, which include exploration of lead-free perovskites to mitigate environmental concerns arising from lead leakage and the pursuit of achieving high-sensitivity and stable detection in aqueous media, summarizing the existing and promising strategies in this field. [ABSTRACT FROM AUTHOR]

A phthalonitrile‐based bent shaped push‐pull dibenzodioxin was synthesized using an efficient and rapid monowave reactor‐assisted protocol in acceptable yields. When aqueous Fe3+ ion solution was added to the bent dibenzodioxin in dimethyl sulfoxide (DMSO), the fluorescence intensity of bent dibenzodioxin at 450 nm was quenched significantly. UV‐visible and fluorimetric measurements displayed high selectivity and sensitivity towards Fe3+ over other metal ions, with a low detection limit of 0.67 μM. Fluorimetric investigations like interference and reversibility test of bent‐dibenzodioxin with Fe3+ led to proving it as a potential canditate for chemosensor application. Job's plot showed 1 : 2 stoichiometry between the bent‐dibenzodioxin and Fe3+ ions respectively and it was proposed that the the binding of one of the Fe3+ ion is from the phenanthroline‐like bent pocket, featuring two oxygen atoms and the other Fe3+ ions binds with the two ortho‐dinitrile units of the bent‐dibenzodioxin. [ABSTRACT FROM AUTHOR]

This study demonstrates a facile solvothermal approach to synthesizing green fluorescent carbon dots (G‐CDs) using baby pumpkin as a natural precursor. The G‐CDs exhibit strong fluorescence emission at 547 nm under excitation at 467 nm, and the highest quantum yield reaching 17.5 % in acetone, making them suitable for a range of applications including sensing, bioimaging, catalysis, and drug delivery. The G‐CDs demonstrate excellent stability under various conditions, such as prolonged light exposure, high salt concentration, extended periods, and elevated temperatures. Furthermore, the G‐CDs show a good linear relationship with Cd2+ within the concentration range of 0 to 16.5 μmol/L, with a linear correlation coefficient of 0.9920. The detection limit (LOD) was calculated to be 0.68 μmol/L. The recovery rate ranges between 85.66% to 97.43%, indicating their potential for use in environmental metal ion detection. This study provides a convenient and economical method for the synthesis of G‐CDs using baby pumpkin as a precursor, offering a sustainable alternative for various applications in sensing, imaging, catalysis, and drug delivery. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) represent a new type of crystalline porous polymers that possess pre‐designed skeletons, uniform nanopores, and ordered π structure. These attributes make them well‐suited for the design of light‐emitting materials. However, the majority of COFs exhibits poor luminescence due to aggregation‐caused quenching (ACQ), resulting from the strong interaction between adjacent layers. To break the limitation, the building units with three methoxy groups on the walls are used to construct TM‐OMe‐EBTHz‐COF, which suppresses the ACQ effects to improve light‐emitting activity of COF. The TM‐OMe‐EBTHz‐COF exhibits a notable emission of yellow‐green luminescence in the solid state, with a remarkably high absolute quantum yield of 21.1%. The methoxy groups and hydrazine linkage form three coordination sites, contributing to excellent performance in metal ions sensing. The TM‐OMe‐EBTHz‐COF demonstrates high sensitivity and selectivity to Fe3+ ion. Importantly, the low detection limit is below 150 nanomolar, ranking it among the best‐performing Fe3+ sensor systems. [ABSTRACT FROM AUTHOR]

One‐pot reactions of catechol‐scaffolding aroylbis(N,N‐diethylthiourea) H2Lcat and mixtures of lanthanide nitrates Ln(NO3)3 (Ln3+=La3+, Nd3+ or Yb3+) or indium(III) chloride InCl3 and [Au(tht)Cl] in methanol in the presence of the supporting base Et3N result in gold(I) {2}‐metallacoronates. Depending on radii of the trivalent metal ions, the corresponding complexes are separated either in the neutral form with the composition {(NO3‐κ2‐O,O')Ln⊂[Au2(Lcat)2]} in the cases of La3+ and Nd3+ or as the 'ion‐pair' {Yb⊂[Au2(Lcat)2]}+(NO3)− for the Yb(III) compound. The cationic complexes can be isolated in higher yields as the PF6− salts {M⊂[Au2(Lcat)2]}+(PF6)− (M3+=Yb3+ or In3+) by treatment of reaction mixtures with (n‐Bu4N)(PF6). [ABSTRACT FROM AUTHOR]

Herein, we report a comparative study on the interactions of different metal ions with fluorinated and non-fluorinated azobenzene-Schiff bases. Three new varieties of fluorinated Schiff bases were synthesized in high yields and changes in their UV-vis absorbance and fluorescence emission when they interacted with various metal ions in EtOH-H2O were studied. It was observed that alkali metals in the presence of F-substituent significantly altered UV-vis absorbance, causing red shifts, whereas transition metal ions caused blue shifts. In all cases, metal interactions increased the fluorescence emission. Interestingly, alkali metal ions intensified the color of parent compounds, whereas transition metal ions turned the solution colorless. We observed that the presence and position of fluorinated substituent had a significant impact on the interaction of metal ions. Interestingly, in the presence of a polar solvent such as DMSO, the interactions increased significantly, the C-F bond appeared to be activated in the presence of alkali metal ions, and the F-substituent was removed very quickly at room temperature as evidenced by the appearance of a very interesting azobenzene-dibenzoazepine compound in ¹H-NMR spectra. To gain deep insights into the nature of interactions, time-dependent ¹H- and 19F-NMR spectroscopy were used, which confirmed the participation of M-F interactions and the formation of new (N and) O...M+...F complexes due to significant changes in the chemical shift of 19F resonance (shielding effect) with respect to free ligands. It was also confirmed that alkali metals interacted at the site containing F-substituents, whereas transition metals preferred a non-fluorinated site. The appearance of a new shielded peak of the F-substituent in 19F NMR was found to be in the decreasing order of the ionic size of metal ions. Interestingly, in the absence of weak bases, electron-withdrawing groups, and other activators and under the action of polar solvents and alkali metal salts, the C-F bond exhibited σ bond donor ability with alkali metal ions, which could be activated. Thus, this method allows for the modulation of a Schiff base to create interesting functional and useful materials. [ABSTRACT FROM AUTHOR]

The N1,N2‐diphenyloxalohydrazide OX(HA)2 chemosensor was synthesized and used as a colorimetric and fluorescent receptor to detect Cu2+ and Fe3+ ions in the presence of other metal ions. A range of physicochemical approaches were utilized to characterize the symmetrical oxalohydrazide‐based receptor, including FT‐IR, 1H and 13C NMR, TGA, and mass spectrometry. According to single crystal X‐ray diffraction investigation, OX(HA)2 crystallizes in monoclinic with space group C2/c. UV‐Vis and fluorescence spectroscopy were used to thoroughly explore OX(HA)2's sensing capabilities towards diverse cations. Using measurements of fluorescence intensity, the binding constant for OX(HA)2 with Cu2+/Fe3+ ions was calculated to be 2.78×103 M−1 and 1.12×103 M−1 with the lower detection limit of 0.43 μM and 0.2 μM respectively. With a 1 : 1 binding mechanism validated by Job's plot, mass spectral analysis, FT‐IR spectra, and density functional theory, the dual‐sensing receptor exhibits remarkable selectivity and sensitivity towards Cu2+ and Fe3+ ions. The average fluorescence lifetimes of OX(HA)2, OX(HA)2+Cu2+, and OX(HA)2+Fe3+ were calculated to be 2.19 ns, 1.73 ns, and 1.26 ns, respectively. This fluorescence lifetime measurement results strongly support the complexation of Cu2+ and Fe3+. When Cu2+ and Fe3+ ions bind with OX(HA)2, they induce the 'Turn‐Off' signal. Then, fluorescence imaging of the OX(HA)2 receptor in MDA‐MB‐231 demonstrated that the receptor holds a lot of promise for usage in bioimaging and their IC50 value for cytotoxicity is 96.96 μg. Furthermore, fluorescence microscopy experiments demonstrate that OX(HA)2 can be utilized as a fluorescent probe for detecting Cu2+ and Fe3+ ions in living cells, making it potentially helpful as an anticancer medication. [ABSTRACT FROM AUTHOR]

The incorporation of crown ether into metal‐organic frameworks (MOFs) is garnered significant attention because these macrocyclic units can fine‐tune the inherent properties of the frameworks. However, the synthesis of flexible crown ethers with precise structures as the fundamental building blocks of crystalline MOFs remains a challenging endeavor, with only a limited number of transition metal examples existing to date. Herein, 18‐crown‐6 and 24‐crown‐8 struts are successfully incorporated into the skeleton of zirconium‐based MOFs to obtain two new and stable crown ether‐based MOFs, denoted as ZJU‐X100 and ZJU‐X102. These newly developed MOFs displayed high porosity and remarkable stability when exposed to various solvents, boiling water, pH values, and even concentrated HCl conditions. Thanks to their highly ordered porous structure and high‐density embedding of specific binding sites within tubular channels, these two MOFs exhibited extremely fast sorption kinetics and demonstrated outstanding performance in the uptake of strontium and cesium ions, respectively. Furthermore, the structures of Sr‐adsorbed ZJU‐X100 and Cs‐adsorbed ZJU‐X102 are solved and confirmed the precise location of Sr2+/Cs+ in the cavity of 18‐crown‐6/24‐crown‐8. This makes modular mosaic of different crown ethers into the skeleton of stable zirconium‐based MOFs possible and promote such materials have broad applications in sorption, sensing, and catalysis. [ABSTRACT FROM AUTHOR]

RNA, a highly charged biopolymer composed of negatively charged phosphate groups, defies electrostatic repulsion to adopt well-defined, compact structures. Hence, the presence of positively charged metal ions is crucial not only for RNA's charge neutralization, but they also coherently decorate the ion atmosphere of RNA to stabilize its compact fold. This feature article elucidates various modes of close RNA–ion interactions, with a special emphasis on Mg2+ as an outer-sphere and inner-sphere ion. Through examples, we highlight how inner-sphere chelated Mg2+ stabilizes RNA pseudoknots, while outer-sphere ions can also exert long-range electrostatic interactions, inducing groove narrowing, coaxial helical stacking, and RNA ring formation. In addition to investigating the RNA's ion environment, we note that the RNA's hydration environment is relatively underexplored. Our study delves into its profound interplay with the structural dynamics of RNA, employing state-of-the-art atomistic simulation techniques. Through examples, we illustrate how specific ions and water molecules are associated with RNA functions, leveraging atomistic simulations to identify preferential ion binding and hydration sites. However, understanding their impact(s) on the RNA structure remains challenging due to the involvement of large length and long time scales associated with RNA's dynamic nature. Nevertheless, our contributions and recent advances in coarse-grained simulation techniques offer insights into large-scale structural changes dynamically linked to the RNA ion atmosphere. In this connection, we also review how different cutting-edge computational simulation methods provide a microscopic lens into the influence of ions and hydration on RNA structure and dynamics, elucidating distinct ion atmospheric components and specific hydration layers and their individual and collective impacts. [ABSTRACT FROM AUTHOR]

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]

We demonstrate the reduction of gold (Au) on silica monoliths by surface decoration of amine and imine (formed by reaction of amine present in 3‐amino propyl triethoxy silane (APTES) and acetone) functionalities on the surface of silica. The reduction of Au3+ to Au0 was confirmed by X‐ray diffraction (XRD), UV‐Diffuse reflectance and X‐ray Photo electron spectroscopic techniques. Without employing the conventional strategies with reducing agents like sodium borohydride and sodium citrate, here, the surface functionalized amine and imine was found to reduce the metal ions, additionally, the surface silanols was found to anchor and serve as the adsorption sites to hold the metal ions prior to reduction. The control experiment was performed with silica monoliths without the surface functionalities displayed no evident reduction of Au3+ to their respective metallic form. Interestingly, the reduction of Au was found to be more facile on imine modified silica, due to the strong electrostatic interaction of highly polarized imine with Au3+ ions. [ABSTRACT FROM AUTHOR]

The deep separation between In(III) and Fe(III) ions is considered as an important technological challenge in the engineering fields. The In(III) ions are closer to the soft acid in terms of Lewis acidity due to the smaller polarizability and greater deformability than the Fe(III) ions, which facilitates the possibility of separating them. Herein, the Lewis basicity of the N‐containing adsorption sites is regulated by the fluorine‐containing group to better match with the In(III) ions rather than Fe(III) ions, causing a significant discrepancy in the binding of the adsorption sites to them. Moreover, targeted programmed desorption techniques based on the potential energy differences of the adsorption sites can achieve the deep separation of In(III) and Fe(III) ions, and reach an exceptional concentration of 20.7 mmol L−1 for In(III) ions in the initial desorption solution with extremely high mass ratio (mIn/mFe = 151.7). This work provides a novel technique for in‐depth separation of In(III) and Fe(III) ions from mixed systems, and a new strategy for separating metal ions with similar or close properties. [ABSTRACT FROM AUTHOR]

An easily synthesizable indole‐derived chromofluorogenic probe InNS has been demonstrated for recognition of trivalent metal ions (i. e. Al3+, Ga3+, In3+ and Fe3+). Both UV‐Vis and emission spectral studies have been employed to assess the cation sensing ability of InNS in semi‐aqueous medium. This probe exhibited a chromogenic response for these metal ions, and the related change was accompanied with the appearance of a new absorption near 376 nm. An obvious color change from pale yellow to dark yellow could also be noticed upon addition of the aforementioned metal ions to the probe's solution. Distinctively from the UV‐Vis analysis, the fluorescence behavior of InNS was completely different; it displayed a 'turn‐on' fluorescence response for only Al3+ among all the studied cations. The detection limit and the association constant (Ka) for Al3+ were determined to be 12.5 nM and 6.85×106 M−1, respectively. A potential 1 : 1 binding mode of Al3+‐InNS has been established based on Job's plot, 1H NMR and DFT analyses. The reversibility experiment was conducted using strongly chelating EDTA ion, and a corresponding logic gate has been devised. In terms of practical applications, the InNS has been utilized to detect Al3+ in human breast carcinoma (MCF‐7) cell lines displaying promising 'turn‐on' bioimaging experiments. [ABSTRACT FROM AUTHOR]

The effects of heavy metals such as Hg(II) and Pb(II) on the human body are profound. Moreover, they pose significant concerns due to industrial development. Thus, the rapid and stable detection of heavy metal ions and related chemicals has emerged as an urgent issue. The application of Differential Pulse Stripping Voltammetry (DPSV) facilitated accurate and rapid detection of Hg2+ utilizing MOF materials and ZIF‐8 as detection agents. Pure ZIF‐8 served as the substrate material. Copper or nickel ions were individually introduced into the substrate material. This process resulted in the formation of bimetallic MOF materials. These materials were designated as CuZn and NiZn, respectively. Transition metal‐doped materials were used to modify the glassy carbon electrode (GCE), resulting in a substantial enhancement in the detection performance of Hg2+. The CuZn/GCE configuration demonstrated the most significant enhancement. When compared to a GCE modified with pure ZIF‐8, both sensitivity and the detection limit for free Hg2+ in the environment experienced increases of 450% and 64%, respectively. Stability and repeatability tests were conducted on the CuZn‐modified GCE. Results indicated that the electrode proved to be very stable and showed strong selectivity in the presence of interfering ions. The sensor modified with CuZn shows promising potential for monitoring trace Hg2+ levels. [ABSTRACT FROM AUTHOR]

In the photolithography process of integrated circuits （IC） manufacturing, it is desired that the photoresist resins have both smaller polydispersity index (PDI) and lower trace metal ion concentrations. The commercial environmentally stable chemical amplified photoresist (ESCAP) resins for 248 nm lithography are synthesized by free radical polymerization with PDI >1.5. Although using atom transfer radical polymerization (ATRP) can result in lower PDI, the potential of high metal ion contamination is a major concern, as the reaction initiators usually are copper‐containing compounds. In this study, copolymer of p‐acetoxy styrene and tert‐butyl acrylate [poly(AOST‐co‐TBA)] is synthesized via ATRP achieving PDI as low as 1.25. It is then purified by ion exchange with two different resins, IRC747 and A15, which are effective at removing Cu and other metal ions. This reduces the total metal ion concentration in the copolymer powder to <30 ppb with individual metal ion <6 ppb. This is the first reported ATRP synthesized ESCAP resin having both low PDI and metal ion concentrations suitable for 248 nm photoresist application. [ABSTRACT FROM AUTHOR]

Natural rubber (NR) consists of mainly cis‐1,4‐polyisoprene with proteins as notable nonrubber components that significantly influence its properties. A relatively unexplored aspect is the role of these proteins in reducing and stabilizing metal ions to form metallic particles. Here, the NR/ZnO composite is successfully prepared by in situ generation of ZnO in the NR latex for the first time. With the aid of the proteins, the amount of ZnO is slightly higher than that formed in the saponified NR latex (SPNR), where some proteins are removed. Importantly, the noncovalent bonds between the proteins and/or amino acids with the ZnO formed in the NR latex can provide the self‐healing behavior of the NR/ZnO composite. However, heating at ≈40 °C is still necessary for reducing the healing time and increasing the self‐healing efficiency of the composite. Nevertheless, greater noncovalent bonds within NR/ZnO hinder rubber molecular chain interdiffusion and rearrangement essential for self‐healing behavior in uncross‐linked rubber, resulting in lower healing efficiency compared to SPNR/ZnO. This study underscores the significance of proteins and/or amino acids on NR's properties, despite their minor presence. Without sophisticated NR modification, this is a very simple and low‐cost technique to achieve the NR/ZnO composite with self‐healing behavior. [ABSTRACT FROM AUTHOR]

The extraction of 73As, 75Se, 197mHg, 212Pb and 210Po on Eichrom pre-filter resin was studied in HCl and HNO3 with batch uptake, kinetic and column experiments. There was significant extraction of mercury in HNO3 and HCl, and polonium and selenium in HCl. The kinetics are sufficient to allow for retention on pre-filter columns, and separations of 73As from 75Se and 197mHg, and 212Pb from 210Po are demonstrated. This retention is important for the development of chemical separations as pre-filter resin is commonly used alongside extraction chromatography resins but its potential for uptake of metal ions is not well characterized. [ABSTRACT FROM AUTHOR]

The prepared activated zirconium oxide was characterized using different analytic techniques and investigated as a new inorganic sorbent to get rid of the chromium and barium ions from the waste stream. Several experiments have been performed, including the impact of contact time, pH, initial ion concentration, temperature, desorption, and the effect of interfering ions. Different isotherm kinetic models were investigated. The outcomes demonstrated that, the second-order kinetic model was appropriate, and the monolayer capacities for the chromium and barium ions were 35.9 and 33.9 mg/g, respectively. Finally, zirconium oxide was recommended to be used as a highly selective adsorbent for hazardous metal ions. [ABSTRACT FROM AUTHOR]

Pyrene derivatives are regularly proposed for use in biochemistry as dyes due to their photochemical characteristics. Their antibacterial properties are, however, much less well understood. New complexes based on 4-[(E)-2-(1-pyrenyl)vinyl]pyridine (PyPe) have been synthesized with metal ions that are known to possess antimicrobial properties, such as zinc(II), cadmium(II), and mercury(II). The metal ion salts, free ligand, combinations thereof, and the coordination compounds themselves were tested for their antibacterial properties through microdilution assays. We found that the ligand is able to modulate the antibacterial properties of transition metal ions, depending on the complex stability, the distance between the ligand and the metal ions, and the metal ions themselves. The coordination by the ligand weakened the antibacterial properties of heavy metal ions (Cd(II), Hg(II), Bi(III)), allowing the bacteria to survive higher concentrations thereof. Mixing the ligand and the metal ion salts without forming the complex beforehand enhanced the antibacterial properties of the cations. Being non-cytotoxic itself, the ligand therefore balances the biological consequences of heavy metal ions between toxicity and therapeutic weapons, depending on its use as a coordinating ligand or simple adjuvant. [ABSTRACT FROM AUTHOR]

Lysyl oxidase‐like 2 (LOXL2) is a Cu2+‐dependent amine oxidase that catalyzes the oxidative deamination of lysine residues of elastin and collagen to generate aldehyde groups. In the active state of LOXL2, its conserved catalytic domain has a lysine tyrosylquinone (LTQ) cofactor and a copper ion. LTQ is post‐translationally derived from Lys653 and Tyr689 of LOXL2. In this study, well‐tempered metadynamics simulations are used to investigate the conformation modulation from the inactive state to active state and obtain the free energy landscape. Interestingly, the simulations show that LTQ precursor residues cannot get close in Zn2+−bound LOXL2, whereas the copper ion binding triggers a conformation change to form an optional structure for LTQ biosynthesis. It is found that a prominent loop, consisting of residues 654–658, hinders the formation of LTQ in Zn2+−LOXL2 by preventing Lys653 from moving into active site of LOXL2, whereas this loop is relatively flexible in Cu2+−LOXL2. After the formation of LTQ, it needs to be activated by adjusting its position to be exposed to the solvent, thus allowing it to react with its substrate proteins. The results indicate that this process involves an intermediate state and that the activation of LTQ overcomes an energy barrier of 5.9 kcal mol−1. [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]

The contamination of water by hazardous industrial discharges and harmful bacteria has evolved into a pressing concern, inflicting considerable harm on both the environment and human well-being. It is imperative that decisive measures are taken to mitigate and eradicate industrial wastewater pollution. In this study, we applied (phosphorus) P-doped carbon quantum dots simultaneously for metal ion sensing and photocatalytic without any post-treatment. P-doped carbon quantum dots (CQDs) were prepared from a green precursor microwave irradiation method. Our investigation delved into the structural, morphological, chemical, and elemental composition through various techniques. The P-CQD presented abundant functional groups on the surface with about 5 nm size. The P dopant and P–O–P bonds confirm the presence of P on CQDs. We investigated the influence of P-doping on the absorption, adsorption, and fluorescence characteristics in detail using UV–visible and photoluminescence (PL) spectroscopy. Our findings revealed that the PL emission in blue region is intricately linked to the excitation and pH levels. A noticeable 33% PL quantum yield was found. PL phenomenon attributed to the functional groups presents on the surface of the CQDs. Further, the potential of P-CQDs for the detection of metal ions specifically Fe3+ and Hg2+ in an aqueous environment was investigated, by employing a fluorescence quenching mechanism. The main factors driving quenching are the energy transfer interaction between carbon dots and metal ions facilitated by a certain interaction involving functional groups and surface traps. Impressively, P-CQDs exhibited a low detection limit of 51 nM for Fe3+ and 81 nM for Hg2+. It is worth noting that the P-CQDs exhibited superior quenching efficiency when exposed to Fe3+ and Hg2+ ions compared to other cations. Additionally, it displayed the ability to degrade methyl orange dye, achieving 70% degradation efficiency within a mere 240 min under ordinary visible light without any further integration with other materials. Thus, our study on P-CQDs demonstrates immense dual potential and efficiency for environmental applications. [ABSTRACT FROM AUTHOR]

Strain improvement via chemical mutagen could impart traits with better enzyme production or improved characteristics. The present study sought to investigate the physicochemical properties of pullulanase produced from the wild Bacillus sp and the mutant. The pullulanases produced from the wild and the mutant Bacillus sp. (obtained via induction with ethyl methyl sulfonate) were purified in a-three step purification procedure and were also characterized. The wild and mutant pullulanases, which have molecular masses of 40 and 43.23 kDa, showed yields of 2.3% with 6.0-fold purification and 2.0% with 5.0-fold purification, respectively, and were most active at 50 and 40 °C and pH 7 and 8, respectively. The highest stability of the wild and mutant was between 40 and 50 °C after 1 h, although the mutant retained greater enzymatic activity between pH 6 and 9 than the wild. The mutant had a decreased Km of 0.03 mM as opposed to the wild type of 1.6 mM. In comparison to the wild, the mutant demonstrated a better capacity for tolerating metal ions and chelating agents. These exceptional characteristics of the mutant pullulanase may have been caused by a single mutation, which could improve its utility in industrial and commercial applications. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the ability of hesperidin (HES) to form metal-complexes (HES-M) by chelation with transition metals such iron(III), copper(II), zinc(II), and silver(I), in addition to screen the antioxidant activity (DPPH free radical scavenging and phosphomolybdenum reduction potential methods PRP), anti-Alzheimer activity [(acetylcholinesterase (AChE)] inhibition assay) and coagulant activity (prothrombin time PT assay). The results indicated that HES could form a 1:1 complex with the studied metals in methanolic solution. The complex has been synthesized and characterized by physicochemical methods. Complexing of hesperidin with metals leads to increase in the antioxidant activity by 15.4-33%. Also, the total antioxidant capacities of HES-M complexes were increased by 13.8-251%. Cu-complex revealed the most increasing antioxidant activity by 33% for DPPH scavenging activity and 251% for PRP activity. The inhibition capacity of the HES, as well as of the HESM complexes on the enzyme AChE, was revealed that only HES-Zn complex has higher anti-Alzheimer activity (IC50 1.18 mg/mL). HES and HES-M complexes led to accelerate the clotting time by 28.9-67.3%, where HES-Zn complex was the most accelerating clotting time by 67.3%. The high increase in total antioxidant activity of hesperidin after chelating with copper (251%) opens the door for further research. [ABSTRACT FROM AUTHOR]

Curcumin (Cur) metal complexes of Mg(II), Ca(II), Cu(II), Cr(III), and Se(IV) were prepared and characterized using elemental analysis, molar conductance, IR, UV-spectra, 1H NMR, SEM, TEM, and X-ray diffraction. The very low values of molar conductance confirm that Cl-ions are absent inside or outside the chelation sphere confirming their non-electrolytic nature, while for Cr(III) Cur is high compared to other curcumin complexes, confirming that Cl-ions are inside the complexation sphere. Based on IR and electronic spectra, the Cur C=O group in enol form chelated to Mg(II), Ca(II), Cu(II), Cr(III), and tetravalent metal (Se). The surface morphology of the curcumin chelates showed an increase in particle size and irregular grains shaped with an elongated morphology. Transmission electron microscopy revealed that the Cur chelates have spherical black spots like shape with a particle size of 72.21-88.75 nm, 34.89-57.33 nm, and 80.71-100 nm for Cu(II), Zn(II), and Se(IV) Cur respectively. X-ray powder diffraction patterns for Cu(II) Cur complexes showed particle size within 70-90 nm; the antioxidant activities of Cur and its metal complexes were assessed. Results showed that the Cur complexes with Cr, Mg, Ca, Cu, or Se showed potent antioxidant activities. Further studies could evaluate the potency of these complexes to elevate the antioxidant defense system and enhance body functions against degenerative diseases, such as aging, Alzheimer's disease, and viral diseases. [ABSTRACT FROM AUTHOR]

BACKGROUND: Metal ions commonly inevitably appear in food products and have adverse effects on high‐internal‐phase emulsions (HIPEs) foods, but conformational conversion of soybean protein isolate (SPI)/soybean soluble polysaccharide (SSPS) on the interface layer of HIPEs influenced by different metal ions has rarely been reported. RESULTS: Here, the conformational conversion of SPI/SSPS induced by Na+, K+, Ca2+, Mg2+ and Fe3+ ions and its effects on HIPEs were investigated. After adding the ions to SPI and SPI/SSPS dispersions, the particle size and zeta potential results showed different degrees of flocculation; the zeta potential and Fourier transform infrared spectra indicated that SPI and SPI/SSPS changes in structure involve electrostatic interactions and hydrogen bonding. Moreover, Raman spectra showed that the content of β‐sheet of SPI/SSPS HIPEs increased with the addition of Ca2+, Mg2+ and Fe3+, suggesting that SPI molecules at the interface formed a more orderly structure. The ultraviolet and fluorescence results showed that the hydrophobic environment of tryptophan and tyrosine residues inside protein molecules played a vital role in the emulsifying stability of SPI. CONCLUSION: These findings suggested that the SPI/SSPS complexes for food applications were not susceptible to ions, thus ensuring complex stability, showing potential for commercial application in the production of emulsions. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In the present study, it has been synthesized a new polymer, OXPESH (oxidized polyethylene functionalized with thiol groups), based on commercially used OXPE (oxidized polyethylene) for possible uses in the removal of heavy metals. Thiol-based oxidized polyethylene was successfully obtained by the esterification process. The synthesized polymeric material was employed as a possible adsorbent for the removal of heavy metal ions from aqueous solutions. Different techniques (1H-NMR, FTIR, ICP-MS, (Elemental Analysis), XPS, SEM–EDX, TGA/DTG) were used to characterize the physical and chemical properties of the obtained adsorbent. it was observed that the optimum pH values for the adsorption capacity and removal efficiency of heavy metal ions were 6–8. It was observed that the adsorbent removed the best Ag+ > Cr3 + > Pb2+ > Al3+ > Cd2+ > Ni2+ > Cu2+ from the aqueous solution. As a result, thiol–based oxidized polyethylene has been demonstrated to be an effective sorbent for the removal of heavy metal ions from aqueous solution, indicating its potential relation with water improvement. [ABSTRACT FROM AUTHOR]

Bacterial laccase has grown significantly crucial on a large scale because they have high catalytic activity and stability. This is the first study in which the laccase gene was amplified from Bhargavaea beijingensis, ligated to the pENTR-TOPO vector, and transformed into Escherichia coli. The novel laccase was purified by Ni–NTA sepharose affinity chromatography. Purified laccase showed optimum pH and temperature of 8.0 and 50 °C, respectively. The novel B. beijingensis laccase exhibited stable activity at a broad range of pH and temperature. The kinetic parameters Km of 0.23 mM and Vmax of 54.6 μmol/min/mg of protein were noted for recombinant laccase toward guaiacol. Laccase activity was significantly influenced by metal ions such as copper, magnesium, and arsenate. The efficacy of laccase in dye decolorization was investigated using various dyes, and a nearly complete decolorization of congo red was recorded. This study confirmed that laccase from B. beijingensis can be produced in the active and stable form to degrade lignin and decolorize dyes. [ABSTRACT FROM AUTHOR]

At present, doping of different alkaline-earth metal ions is mainly used to tune the emission peak of europium (Eu) ions in glasses. However, the optimization of Eu-doped glasses is hindered due to limited discussion on the relationship between local glass network structure, concentration of Eu ion dopants, and visible light emission by Eu ions. In this study,we prepared two series of borosilicate glasses doped with Eu ions, by varying the ratio of SiO2 to B2O3 and adjusting the concentration of Eu ion dopants to obtain cyan emission. The optical properties, structure, and differential scanning calorimetry (DSC) of the investigated glasses were systematically studied. With gradual increase in the content of SiO2, red shifting from 471 nm to 492 nm was observed under excitation at 410 nm, with the introduction of Eu2O3 also causing a redshift from 471 nm to 488 nm. The spectral results also revealed that under excitation at 410 nm all the glass samples exhibited cyan emission, with the optimal cyan peak at 492 nm (Si-45) and the strongest cyan emission at Eu-0.4 (480 nm). By adjusting the concentration ratios of Si to B in europium-doped borosilicate glass, it was observed that by altering the [SiO4] tetrahedra, [BO4] tetrahedra, and [BO3] triangles within the glass ultimately cyan emission can be achieved. By varying the doping concentration of Eu ion to change the degree of local Eu ion clustering in the glass system, cyan emission can be achieved by tuning the emission peak. [ABSTRACT FROM AUTHOR]

As an adsorbent material, Metal-Organic Framework (MOF) provides several advantages, such as large surface area and pore volume, as well as stability in aqueous systems both in acidic, basic, and neutral conditions. The research successfully made a metal organic framework (MOF) from chromium and perylene that was modulated by isonicotinic acid. It was done using three different methods: hydrothermal (Cr-PTC-HIna-HT), solvothermal (Cr-PTC-HIna-ST), and sonochemical (Cr-PTC-HIna-SC). The Cr-PTC-HIna-SC showed the greatest Pb2+ ion adsorption capacity. The optimum adsorption of Pb2+ ions occurred at 150 ppm Pb2+ ion concentration, pH of 5, 90 min of contact time, and an adsorption capacity of 149.95 mg/g at 35 °C. The dominant adsorption isotherm model is the Langmuir isotherm model with R² = 0.9867 and follows the pseudo-second-order. The selectivity test showed that Cr-PTC-HIna-SC MOF could adsorb more Cd2+ ions than Pb2+ ions, with 250 mg/g being the best amount. [ABSTRACT FROM AUTHOR]

Heavy metal ions can be introduced into the water through several point and non-point sources including leather industry, coal mining, agriculture activity and domestic waste. Regrettably, these toxic heavy metals may pose a threat to both humans and animals, particularly when they infiltrate water and soil. Heavy metal poisoning can lead to many health complications, such as liver and renal dysfunction, dermatological difficulties, and potentially even malignancies. To mitigate the risk of heavy metal ion exposure to humans and animals, it is imperative to extract them from places that have been polluted. Several conventional methods such as ion exchange, reverse osmosis, ultrafiltration, membrane filtration and chemical precipitation have been used for the removal of heavy metal ions. However, these methods have high operation costs and generate secondary pollutants during water treatment. Biosorption is an alternative approach to eliminating heavy metals from water that involves employing eco-friendly and cost-effective biomass. This review is focused on the heavy metal ions contamination in the water, biosorption methods for heavy metal removal and mathematical modeling to explain the behaviour of heavy metal adsorption. This review can be helpful to the researchers to design wastewater treatment plants for sustainable wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] Silk is one of the toughest fibrous materials known despite spun at ambient temperature and pressure with water as a solvent. It is a great challenge to reproduce high-performance artificial fibers comparable to natural silk by bionic for the incomplete understanding of silkworm spinning in vivo. Here, we found that amphipol and digitonin stabilized the structure of natural silk fibroin (NSF) by a large-scale screening in vitro , and then studied the close-to-native ultrastructure and hierarchical assembly of NSF in the silk gland lumen. Our study showed that NSF formed reversible flexible nanofibrils mainly composed of random coils with a sedimentation coefficient of 5.8 S and a diameter of about 4 nm, rather than a micellar or rod-like structure assembled by the aggregation of globular NSF molecules. Metal ions were required for NSF nanofibril formation. The successive pH decrease from posterior silk gland (PSG) to anterior silk gland (ASG) resulted in a gradual increase in NSF hydrophobicity, thus inducing the sol-gelation transition of NSF nanofibrils. NSF nanofibrils were randomly dispersed from PSG to ASG-1, and self-assembled into anisotropic herringbone patterns at ASG-2 near the spinneret ready for silkworm spinning. Our findings reveal the controlled self-assembly mechanism of the multi-scale hierarchical architecture of NSF from nanofibrils to herringbone patterns programmed by metal ions and pH gradient, which provides novel insights into the spinning mechanism of silk-secreting animals and bioinspired design of high-performance fibers. [ABSTRACT FROM AUTHOR]

The extractant-assisted transport of metal ions from aqueous to organic environments by liquid--liquid extraction has been widely used to separate and recover critical elements on an industrial scale. While current efforts focus on designing better extractants and optimizing process conditions, the mechanism that underlies ionic transport remains poorly understood. Here, we report a nonequilibrium process in the bulk aqueous phase that influences interfacial ion transport: the formation of metastable ion--extractant precipitates away from the liquid--liquid interface, separated from it by a depletion region without precipitates. Although the precipitate is soluble in the organic phase, the depletion region separates the two and ions are sequestered in a long-lived metastable state. Since precipitation removes extractants from the aqueous phase, even extractants that are sparingly soluble in water will continue to be withdrawn from the organic phase to feed the aqueous precipitation process. Solute concentrations in both phases and the aqueous pH influence the temporal evolution of the process and ionic partitioning between the precipitate and organic phase. Aqueous ion--extractant precipitation during liquid--liquid extraction provides a reaction path that can influence the extraction kinetics, which plays an important role in designing advanced processes to separate rare earths and other minerals. [ABSTRACT FROM AUTHOR]

This study investigates the flotation performance of coal gasification fine slag in the presence of metal ions with different valences. The impact of metal ions on the surface topography, wettability, zeta potential, functional group, and particle size distribution of coal gasification fine slag were analyzed. The results demonstrated that K+, Ca2+, Mg2+, and Al3+ all have a positive effect on flotation, with Al3+ being particularly effective. At a concentration of 0.2 mol/L, Al3+ increased the recovery of combustible matter in coal gasification fine slag from 66.70% to 91.05% compared to deionized water. Metal ions reduce the absolute value of the gasification fine slag potential, compress its double layer while increasing its surface hydrophobicity. Higher ion concentration leads to a closer-to-zero potential and increased hydrophobicity. Additionally, Al3+ promote diesel adsorption onto coal gasification fine slag. This work explains the effects of metal ions on coal gasification fine slag flotation. [ABSTRACT FROM AUTHOR]

Owing to their capacity for dynamically linking two or more functional molecules, supramolecular coordination complexes (SCCs), exemplified by two-dimensional (2D) metallacycles and three-dimensional (3D) metallacages, have gained increasing significance in biomedical applications. However, their inherent hydrophobicity and self-assembly driven by heavy metal ions present common challenges in their applications. These challenges can be overcome by enhancing the aqueous solubility and in vivo circulation stability of SCCs, alongside minimizing their side effects during treatment. Addressing these challenges is crucial for advancing the fundamental research of SCCs and their subsequent clinical translation. In this review, drawing on extensive contemporary research, we offer a thorough and systematic analysis of the strategies employed by SCCs to surmount these prevalent yet pivotal obstacles. Additionally, we explore further potential challenges and prospects for the broader application of SCCs in the biomedical field. [ABSTRACT FROM AUTHOR]

The methylation of p-tert-butylcalix[4]arene in the distal 1,3-phenolic sites provides H2L = {p-tert-butylcalix[4](OMe)2(OH)2arene}. This unit acts as a rigid coordinating ligand to early and late lanthanide metal ions, enabling the construction of two families of mononuclear compounds featuring (N(nBu)4)[LnIIIL(acac)2]·CH3CN (Ln = Pr (1), Nd (2), Ho (3), and Er (4)) and (N(nBu)4)2[LnIIIL{Mo5O13(OMe)4(NO)}]·CH2Cl2 (Ln = Nd (5) and Er (6)). The metal ions adopt distorted bicapped trigonal prismatic coordination environments, resulting in slow relaxation of the magnetization for 4. These compounds exhibit reversible redox waves at positive potentials, centered within the calix[4]arene ligand, representing a new type of calix[n]arene-based electrochemical activity induced by coordination to the metal centers. [ABSTRACT FROM AUTHOR]

The goal of this study was to investigate how the electron-donating capability around the lower valent metal ion and the electron-accepting capability of the higher valent metal ion influence metal to metal charge transfer (MMCT) properties in mixed-valence complexes. A series of trinuclear ruthenium complexes represented as [Ru2(ap-4-Me)3(CH3COO)N≡CRuCpMex(dppe)][PF6] (CpMex = polymethylcyclopentadienyl, x = 0, 1, and 5; and dppe = 1, 2-bis(diphenylphosphino)ethane, ap-4-Me = 2-anilino-4-methylpyridine) and their one-electron oxidized products were synthesized and fully characterized. The UV–vis-NIR spectra confirmed that as the electron donor character of the CpMex(dppe)RuCN fragment enhanced or the electron-accepting capability of the higher valent diruthenium cluster increased, the RuII → Ru V2 or Ru VI2 Ru2 MMCT bands shifted to lower energies, which was supported by TDDFT calculations. [ABSTRACT FROM AUTHOR]

In this work, we develop a dual recycling amplification aptasensor for sensitive and rapid detection of lead ions (Pb2+) using fluorescence and surface-enhanced Raman scattering (FL-SERS). The aptasensor allows targeted cleavage of substrates through specifically binding with the Pb2+-dependent aptamer (M-PS2.M). Ultrasensitive detection of trace Pb2+ has been achieved using an enzyme-free nonlinear hybridization chain reaction (HCR) and the FL-SERS technique. The lower limit of detection (LOD = 3σ/k) is 0.115 pM in FL mode and 1.261 fM in SERS mode. The aptasensor is characterized by high reliability and specificity, among other things, to distinguish Pb2+ from other metal ions. In addition, the aptasensor can detect Pb2+ in actual water with good recovery. Compared with the single-mode aptasensor, the dual-mode aptasensor is characterized by high reliability, an extensive detection range, and high specificity. [ABSTRACT FROM AUTHOR]