Toxic Ions Research Articles

Detection of fluoride ions using carbon quantum dots derived from coal washery rejects via an on–off–on fluorescence mechanism: a smartphone-based image-processing and machine learning approach

An on–off–on fluorescence process-based fluoride ion sensor is developed by using highly fluorescent carbon quantum dots (CQDs) derived from coal washery rejects/waste coal (CWRs) and demonstrated through smartphone.

Evaluation of Type III Adhesive Mortar (ACIII) and Gypsum as Precipitating Agents of Copper and Lead

Heavy metals exhibit characteristics such as nonbiodegradable nature, toxic character, bioaccumulation capability, and ability to transit over long distances. The widespread application of these metal ions in various industrial sectors has led to an increase in their release into the environment. Chemical precipitation has been one of the technologies used to remove heavy metals from wastewater, involving a process in which chemical agents are added to wastewater with dissolved toxic metal ions, which react with the metals, forming insoluble precipitates. Therefore, the present study aimed to assess the potential of gypsum and adhesive mortar type III (ACIII) as precipitating agents for lead (Pb) and copper (Cu) ions, as well as to evaluate the toxicity of precipitation products on Drosophila melanogaster. Experiments using ACIII mortar waste as a precipitating agent for Cu ions were obtained using a glass filter composed of 04 chambers and 04 antechambers, while the potential of gypsum as a Pb ion precipitant was evaluated by adding gypsum powder to a beaker containing a Pb ions solution. The toxicity of the precipitation products was evaluated by observing the mortality and negative geotaxis parameters on D. melanogaster. In the tests using ACIII mortar as a precipitating agent for Cu, retention percentages progressively varied, obtaining 98.82% at a concentration of 30 mg/L. Meanwhile, gypsum obtained retention percentages that varied from 32.83 to 98.61% for Pb. It was found that the precipitates of Cu and Pb resulted in alterations in the survival and locomotion rates of D. melanogaster only at the highest evaluated concentrations. In conclusion, the results obtained indicated that geomaterials such as ACIII mortar and gypsum have potential for the removal of Cu and Pb from aqueous solutions. Moreover, the precipitation stages by these materials also impact in decreasing the toxicity of metal ions to the evaluated model organism.

Pre and post-operative serum levels of titanium cobalt and aluminium after implant placement.

The preoperative serum levels and postoperative serum levels of titanium, cobalt and aluminium from dental implants in order to assess the release of these ions and to assess any risk of toxicity from these ions after dental implant placement is of interest to dentists. It was observed that there was very slight increase in serum concentration of titanium, cobalt and aluminium after 12 months of placement of implants as compared to before placement of implants. However the increase was non-significant statistically. Our study concluded that the use of dental implants does not pose any risk of toxicity of metal ions like titanium, aluminium and cobalt because of very slight non-significant increase in serum levels of these ions 12 months after implant placement.

A ratiometric fluorescent probe with a large Stokes shift for the detection of Hg2+ and its applications in environmental sample and living system analysis.

Toxic mercury ions (Hg2+) can cause serious environmental pollution and accumulate in living organisms via the food chain. Therefore, monitoring Hg2+ is crucial in ensuring the safety of ecosystems and organisms. In this work, a novel ratiometric fluorescent probe CMT (5-(4-(diphenylamino)phenyl)-1-(7-hydroxy-coumarin-3-yl)-4-pentene-1,3-dione) based on coumarin was developed for detecting Hg2+, which displayed obvious fluorescence changes, a low detection limit (2.24 × 10-7 M), good selectivity, and a large Stokes shift (255 nm). The CMT probe could detect Hg2+ in real environmental soil and water samples. Furthermore, the CMT probe enabled the naked-eye detection of Hg2+ using test paper experiments. CMT was also applied for fluorescence imaging in living zebrafish and plants. This work provides a highly efficient tool for monitoring Hg2+ in environmental samples and biological systems.

A reaction based carbazole-indolium conjugate probe for the selective detection of environmentally toxic ions.

A nucleophilic addition based chemodosimeter was designed and synthesized with a carbazole donor and an indole acceptor. The addition of a cyanide ion to an electron-deficient indole moiety disrupts the acceptor-donor relationship, resulting in noticeable color shifts and spectrum differences in both the absorption and emission profiles. The design has a D-π-A molecular arrangement. Selectivity was investigated in 90% aqueous DMSO solution of probe CI with various anions such as SCN-, PF6-, NO3-, N3-, I-, HSO4-, CN-, H2PO4-, F-, HS-, ClO4-, Cl-, Br-, and AcO-. An intermolecular charge transfer (ICT) band at 506 nm in the UV-visible spectra vanished and the intensity of emission was quenched at 624 nm upon the addition of CN- ions. These outcomes demonstrate the effective nucleophilic addition of cyanide ions to the electron-deficient indole moiety of the probe, resulting in the formation of a new adduct in which the ICT transition is interrupted when π conjugation is blocked. The Job plot, 1H NMR spectroscopy, and HRMS analysis confirmed the formation of a new product. An outstanding response was shown by paper test strips made using probe molecules for the easy detection of cyanide ions in aqueous solutions. Besides, the probe selectively senses cyanide ions in different water samples.

Relationship of soil salinatization in Apsheron with chlorophyll content

The effect of saline ions (Сl−, SO4−2, and CO3−2) on the accumulation of chlorophylls in the leaves of new decorative tree-shrub plants introduced on salted Apsheron soils, their degree of salinity resistance, and the dependence of chlorophyll content on the types of saline ions are studied. A direct correlative relationship was established between the type of salinization and the accumulation of green pigments. It was revealed that toxic ions of chloride, sulfate and carbonate entering the root system and through it into the leaves of the studied species have a negative effect on the structure of chloroplasts, promote hydrolysis of protein compounds, breakdown of the protein-chlorophyll bond, accumulation of intermediate products of amides, cadoverin, putrescine and ammonia. The latter lead to tissue and their death.

Photo-triggered AuAg@g-C3N4 composite nanoplatform for multimodal broad-spectrum antibacterial therapy.

Strategies based on nanomaterials for sterilization address the problem of antibiotic resistance faced by conventional antimicrobials, with the contribution of photocatalytic compounds being particularly prominent. Herein, to integrate multiple bactericidal techniques into a system for generating synergistic antibacterial effects, a novel photo-triggered AuAg@g-C3N4 composite nanoplatform was constructed by anchoring AuAg on the surface of a g-C3N4 layer. As the composite nanoplatform had a lower bandgap and superior visible light utilization efficiency, it could facilitate free electron transfer better and exhibit superior photocatalytic activity under light conditions. Moreover, the AuAg@g-C3N4 composite nanoplatform integrated the bactericidal modes of silver ion toxicity, physical disruption of bacterial cell membranes by the multilayer structure, and excellent photocatalytic activity, exhibiting extremely superior bactericidal effects against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis, with a bactericidal efficiency of up to 100%.

Metal copper and silver revealed potent antimicrobial activity for treating Caenorhabditis elegans infected with carbapenemase-producing Klebsiella pneumonia.

The increasing issue of bacterial resistance, coupled with inadequate progress in developing new antibiotics, necessitates exploring alternative treatments. Antibacterial biomaterials, such as silver and copper, possess advantageous properties such as heat resistance, durability, continuity, and safety. Particularly, they can effectively eliminate pathogenic bacteria while preserving cellular integrity, emphasizing the necessity of identifying optimal metal ion concentrations for practical application. Caenorhabditis elegans (C. elegans) can serve as a noteworthy model in this context. This study employed a C. elegans infection model to assess the efficacy of antibacterial metal ions. Hematoxylin-eosin (HE) staining and inductively coupled plasma mass spectrometry (ICP-MS) assay were utilized to determine the toxic levels of metal ions in mice. Additionally, RNA sequencing (RNA-seq) and assessment of reactive oxygen species (ROS) production in the C. elegans model were conducted to elucidate the mechanisms underlying metal ion toxicity. Silver ion concentrations ranging from 10-6 to 10-7 M and copper ion concentrations ranging from 10-4 to 10-5 M exhibited antimicrobial properties without eliciting cytotoxic effects. Analysis of the transcriptome data derived from mRNA isolated from C. elegans indicated that CRKP infection activated the FoxO signaling pathway, potentially leading to ROS accumulation and C. elegans demise. In conclusion, C. elegans serves as a comprehensive infection model for assessing antibacterial metal ions.

Nanozyme as detector and remediator to environmental pollutants: between current situation and future prospective.

The term "nanozyme" refers to a nanomaterial possessing enzymatic capabilities, and in recent years, the field of nanozymes has experienced rapid advancement. Nanozymes offer distinct advantages over natural enzymes, including ease of production, cost-effectiveness, prolonged storage capabilities, and exceptional environmental stability. In this review, we provide a concise overview of various common applications of nanozymes, encompassing the detection and removal of pollutants such as pathogens, toxic ions, pesticides, phenols, organic contaminants, air pollution, and antibiotic residues. Furthermore, our focus is directed towards the potential challenges and future developments within the realm of nanozymes. The burgeoning applications of nanozymes in bioscience and technology have kindled significant interest in research in this domain, and it is anticipated that nanozymes will soon become a topic of explosive discussion.

A novel bola-molecular self-assembling hydrogel for enhancing diabetic wound healing

HypothesisChronic wounds, particularly those caused by diabetes, pose a significant challenge for clinical treatment due to their prolonged healing process and associated complications, which can lead to increased morbidity. A biocompatible hydrogel with strong antibacterial properties and the ability to promote angiogenesis can be directly absorbed in the wound site for healing. ExperimentsA series of self-healing, antibacterial bolaamphiphilic supramolecular self-assembling hydrogels (HLQMes/Cu) were developed based on metal–ligand coordination between various concentrations of Cu2+ solution and the head group of l-histidine methyl ester in HLQMes. This is the first report on the application of bola-molecular supramolecular hydrogels for the treatment of chronic wounds. FindingsThe bola-molecular hydrogels reduced the toxicity of copper ions by coordination, and the HLQMes/Cu hydrogel, with 1.3 mg/mL Cu2+ (HLQMes/Cu1.3), demonstrated good biocompatibility and antibacterial properties and effectively enhanced wound healing in a diabetic wound model with full-thickness injuries. Immunohistochemical analysis revealed that the HLQMes/Cu1.3 hydrogel enhanced epithelial formation and collagen deposition in wounds. Immunofluorescence studies confirmed that the HLQMes/Cu1.3 hydrogel attenuated the expression of proinflammatory factor (IL-6) and promoted angiogenesis by upregulating α-SMA and CD31. These findings demonstrate the potential of this bolaamphiphilic supramolecular self-assembling hydrogel as a promising candidate for diabetic wound treatment.

Theoretical study of the adsorption capacity of potentially toxic Cd2+, Pb2+, and Hg2+ ions in hemicellulose matrices

Hemicellulose is widely available in nature, is a sustainable resource and has a wide range of applications. Among them, adsorption stands out for the removal of potentially toxic ions. Thus, in the study, the adsorption of Cd2+, Pb2+ and Hg2+ ions in two hemicellulose matrices were elucidated through computational simulations using density functional theory. Molecular electrostatic potential and frontier molecular orbitals demonstrated whether the interactions could happen. Four interaction complexes were highlighted due to the interaction energy criteria, ΔEBind, ΔH and ΔG < 0.00 kcal mol−1, that is: Hm1… Pb (1); Hm2… Pb (3); Hm2…Cd (4) and Hm2…Hg (4) and the results show that they occur through physisorption. In structural parameter studies, interaction distances smaller than 3000 Å were identified, which ranged from 2.253 Å to 2.972 Å. From the analysis of the topological parameters of QTAIM, it was possible to characterize the intensities of the interactions, as well as their nature, which were partially covalent or electrostatic in nature. Finally, based on the theoretical results, it can be affirmed that the hemicellulose can interact with Cd2+, Pb2+ and Hg2+ ions, evidencing that this study can support further experimental essays to remove contaminants from effluents.

DESENVOLVIMENTO E ANÁLISE DE UM MÉTODO ALTERNATIVO PARA REMOÇÃO DE METAIS POTENCIALMENTE TÓXICOS DA ÁGUA EMPREGANDO MATERIAIS SORVENTES

The current work presents the use of a sorbent material to develop an alternative method for removing lead and barium from public water supplies. The sorbent material used was coconut fiber, which in addition to mitigating environmental pollution by reusing discarded waste, aids in the treatment of public water supplies by removing potentially toxic ions where conventional methods are not effective. In the alternative method used, we have a system of fixed bed reactors connected in series, with a volume of 0.250 L in each reactor. To characterize the adsorption process, we analyzed the variables pH, contact time, initial metal concentration, concentration of the sorbent material, and flow rate. Analysis of variance (ANOVA), multivariate analysis of variance (MANOVA), and the T-test were carried out. The parameters initial metal concentration and flow rate were shown to be non-significant for the confidence interval adopted in the conditions of the current work. The removal of Pb2+ and Ba2+ ions was greater than 60% in all the parameters studied, and in a single pass through the reactors, showing the viability of this procedure. Coconut fiber presented appropriate characteristics for the biosorption of lead and barium ions, constituting a sustainable and promising process to be used together with classical water treatment processes to remove potentially toxic metals.

Strigolactone-mediated amelioration of salinity stress in bread wheat: Insights from phytochemical and ion channels related genes expression analyses

Foliar application of growth regulators seems to alleviate the adverse effects of abiotic stresses in plants through different mechanisms such as antioxidative and gene expression regulation. As an important abiotic stress, salinity has an enormous negative impact on crop plants such as bread wheat. In the present study, exogenous strigolactone (GR24) was considered for its potential stress-mitigating effect in two contrasting wheats cultivars (‘Arta’ and ‘Karchia’) grown under 2,053,100 mM NaCl stress (10 dS m−1). Yield-related traits, oxidative (APX, POX, CAT, H2O2, MDA, GB and Proline), ionic indices (Na+ and K+ content in leaf and root), and the expression of a selected set of oxidative stress related genes (TaAPX, TaGPX, TaP5CS, TaNHX2, TaSOS1, TaHAK, TaAKT2 and TaHKT2;1) were surveyed in the flowering stage. Strigolactone application (10 μM) had a significant effect on the induction and improvement of biochemical and ionic features such as reducing the electrolyte leakage, H2O2 and MDA or increasing the grain yield, total protein, proline, GB and antioxidant enzymes (APX, POX) activity, of salinity-stressed plants. The gene expression analysis with real-time PCR showed transcriptional variation of selected genes in response to salt stress and GR24. Improved homeostasis in Na+ and K+ and their ratio was found to be correlated with the expression of the antiporter genes and the consequent reduction of ion toxicity. The findings of this study can improve our knowledge about complex mechanism of strigolactone plant hormone during salt stress in crop plans to mitigation of salinity stress.

Ultrasensitive Visual Tracking of Toxic Cyanide Ions in Biological Samples Using Biocompatible Metal–Organic Frameworks Architectures

The extraordinary accumulation of cyanide ions within biological cells is a severe health risk. Detecting and tracking toxic cyanide ions within these cells by simple and ultrasensitive methodologies are of immense curiosity. Here, continuous tracking of ultimate levels of CN−-ions in HeLa cells was reported employing biocompatible branching molecular architectures (BMAs). These BMAs were engineered by decorating colorant-laden dendritic branch within and around the molecular building hollows of the geode-shelled nanorods of organic–inorganic Al-frameworks. Batch-contact methods were utilized to assess the potential of hollow-nest architecture for inhibition/evaluation of toxicant CN--ions within HeLa cells. The nanorod BMAs revealed significant potential capabilities in monitoring and tracking of CN− ions (88 parts per trillion) in biological trials within seconds. These results demonstrated sufficient evidence for the compatibility of BMAs during HeLa cell exposure. Under specific conditions, the BMAs were utilized for in-vitro fluorescence tracking/sensing of CN− in HeLa cells. The cliff swallow nest with massive mouths may have the potential to reduce the health hazards associated with toxicant exposure in biological cells.

Surface Modification of NiTi Alloy with Sputtered Tantalum Coatings to Improve its Hardness, Corrosion Resistance and Biocompatibility

In this research, titanium alloys including smart nitinol (NiTi) were studied. The (NiTi) alloy tends to emitting (Ni) toxic ions due to its low resistance to corrosion within the body conditions over time. For (NiTi) coating process, the magnetron plasma sputtering (DC) technique was used with Aragon gas ratio of (90%) and Oxygen of (10%) in order to coat the alloy with Tantalum and its Oxide (Ta2O[Formula: see text] thin films. This is one of the methods used to improve the biocompatibility and better adhesion stability of the membrane on the (NiTi) surface, since Tantalum and its oxides are biocompatible and are not affected by the body fluids. Hardness, corrosion and biocompatibility were tested. The results showed improvement in the nominated properties using this coating technique. The hardness for the non-coated sample was (630 Kgf/mm[Formula: see text], meanwhile, the coated sample recorded (762 Kgf/mm[Formula: see text] using sputtering power of (25 W) with a thickness of (226 nm). Tantalum and its precipitated oxides on a pillar of thickness (90.4–226 nm) also exhibited a biocorrosion enhancement, when it was immersed in a Simulated Body Fluid (SBF). The corrosion rate for the non-coated sample was (1.204 × 10[Formula: see text], meanwhile for the coated sample, its value was (3.453 × 10[Formula: see text] at sputtering power of (15 W), considered as the lower corrosion rate. The scanning electron micrographs also showed an increase in the biocompatibility for the coated nitinol alloys (NiTi) in comparison with the non-coated, ones since it showed a clear formation of Hydroxyapatite (HA) on the sample surface after immersion in the SBF. This behavior was confirmed by the XRD measurements, which presented higher HA peaks on the coated samples surface in comparison with the non-coated samples.

Light-Augmented Multi-ion Interaction in MXene Membrane for Simultaneous Water Treatment and Osmotic Power Generation.

The mixing of wastewater and natural water releases abundant osmotic energy. Harvesting this energy could significantly reduce the energy and economic cost of water treatment, leading to sustainable wastewater treatment technology. Yet, such energy harvesting is highly challenging because it requires a material that is highly permeable to nontoxic ions while rejecting toxic ions in wastewater to reach high power density and prevent environmental pollution. In this work, we demonstrate that a light-augmented biomimetic multi-ion interaction in an MXene membrane can simultaneously realize high permeability of Na+ ions for enhanced osmotic power generation and high selectivity to heavy metal ions up to a ratio of 2050 for wastewater treatment. The Na+ permeability is enhanced by the photothermal effect of the MXene membrane. The transport of heavy metal ions, however, is suppressed because, under angstrom-confinement, heavy metal ions are strongly electrostatically repelled by the increased number of permeating Na+ ions. As a result, the membrane can stably generate osmotic power from simulated industrial wastewater, and the power density can be enhanced by 4 times under light illumination of approximate 1 sun intensity. This work highlights the importance of multi-ion interaction for the transport properties of ionic materials, which remains rarely investigated and poorly understood in previous studies.

Ultra-sensitive mercury detection from surface wrapping of carbon dots reduced and decorated silver nanoparticles on SERS fiber probes

Highly selective and sensitive detection of toxic mercury ions (Hg2+) has become a critical issue in recent decades, due to increasing environmental and health requirements. Herein, carbon dots reduced and decorated Ag (CDs/Ag) nanoparticles based fiber probes were fabricated, providing a “turn-off” surface-enhanced Raman spectroscopy (SERS) for low-concentration Hg2+ ions detection. The CDs/Ag nanoparticles fiber probe exhibits better SERS performance than that of Ag nanoparticles fiber, attributed to the stronger electromagnetic intensities induced by localized surface plasmon resonance (LSPR) and larger hot-spot areas resulting from the interaction between silver nanoparticles and carbon dots, under 532 nm beam excitation. As low as 10−11 M Hg2+ ions can be detected through the decrease in Raman scattering intensities of CV molecules, due to the SERS inactive Hg metal layer wrapping the surface of silver nanoparticles, through the reduction of Hg2+ ions by carbon dots. The dropping of silver nanoparticles’ LSPR induced absorption peak, EDS elemental mapping, and XPS analysis all confirm that the wrapping decreases the LSPR effect and corresponding Raman intensity. Furthermore, the detection shows high selectivity and can only be applied for detecting Hg2+ ions, owing to the reduction capability of carbon dots. The close analysis results obtained using SERS fiber probes and commercial inductively coupled plasma-mass spectrometry (ICP-MS) for detecting Hg2+ ions in real water sample confirm the reliability of this detection method. This research indicates the CDs/Ag fiber probe has a great potential application for environmental Hg2+ ions detection.

Microscale thermophoresis sensor for Cd2+ using aptamer with tetramethylrhodamine label at an internal site

Rapid sensitive detection of toxic cadmium ion (Cd2+) is demanded in environmental analysis and food safety. Aptamer against Cd2+ becomes attractive recognition element for Cd2+ sensors. The emerging microscale thermophoresis (MST) technique brings new power for optical biosensors construction by employing fluorescently labeled ligand, which measures fluorescence response of samples inside capillaries to localized infrared (IR) laser heating. Herein, we reported a MST aptasensor for Cd2+ by using the aptamer with tetramethylrhodamine (TMR) label at an internal site, and demonstrated that TMR position had large influence on MST responses to Cd2+. The 15-mer aptamer with a TMR conjugated on the internal 12th thymine (T) generated a much larger MST signal change upon Cd2+ binding than the aptamer with TMR labeled at terminals. By utilizing the optimal aptamer probe with TMR labeled at the internal T site, we achieved detection of Cd2+ with a detection limit about 0.5 nM, and the MST aptasensor allowed to detect Cd2+ in real water samples. This work is helpful for developing sensitive aptamer MST sensors for wide applications.

Efficient remediation of heavy metal-contaminated water using a magnetically collectible nanoscale Cu/Fe/rGO primary battery

The removal of highly toxic heavy metal ions is essentially the migration of heavy metal ions from water to materials through adsorption, complexation, exchange, and other forms. However, heavy metals still exist as highly toxic ions on the surface of materials, easily desorbed, and cause secondary pollution. In this study, a novel primary battery of graphene-supported zero-valent copper/iron bimetallic composites (Cu/Fe/rGO) was first prepared with copper as the positive electrode, iron as the negative electrode, and graphene as the "wire". The network-like nanoscale primary battery was fabricated for the reduction and removal of typical highly toxic heavy metal ions (Pb2+) from the water environment. The removal rate of Pb2+ within 20 min was 95.28%. The Pb-immobilized Cu/Fe/rGO primary battery after treatment can be easily separated via a weak magnetic field and maintained an excellent removal rate of Pb2+ during 6 cycles of use. The great potential of Cu/Fe/rGO primary battery in Pb2+ reduction removal was due to its high reduction ability, large surface area, and magnetic separability. This study provides an important foundation for the rapid and stable removal of heavy metals from water, which may have a tremendous application prospect in environmental fields.

Conductometric study of hydroelectrochemical parameters for the interaction of cadmium bromide in lump and nano forms with Orange G dye

The hydroelectrochemical behaviour of cadmium bromide was investigated in the presence of the dye Orange G. This information can be used to develop conductometric sensors for detecting these substances, understand how they behave in aqueous solutions, and design effective procedures for removing the extremely toxic heavy cadmium ions from contaminated water sources. The hydroelectrochemical parameters for the interaction between lump and nanoCdBr2 with Orange G dye were investigated conductometrically in aqueous solutions at different temperatures. CdBr2 interacts with Orange G as a ligand, resulting in a decrease in conductivity. However, the interaction was more significant with nanoCdBr2, which showed a higher decrease in conductivity compared to lump CdBr2. Two stiochiometric complexes, 1:1 and 1:2, were produced; Kf and ΔGf are higher for 1:1 than for 1:2 (CdBr2/Orange G). With rising temperatures, the formation constants decreased, and the negative sign of ΔGf indicated the spontaneity of the reaction, which increased with rising temperatures. The negative values of (ΔHf) revealed the complexation's exothermic nature, whereas the positive entropy (ΔS) values confirmed that the complex formation depended on molecular entropy since the complex formation was favored by an increase in molecular disorder. The results of our investigation can be utilised to enhance comprehension of the behaviour of these materials in aqueous solutions and create efficient protocols for the removal of very toxic heavy metal cadmium ions from polluted water sources. We think that our study advances the discipline and offers a distinctive viewpoint on this subject.