Chelation Mechanism Research Articles

Folic acid-coupled phosphorylated Fe2+ chelating peptide: The properties of Fe2+ chelating capacity and mechanisms of anti-gastrointestinal enzyme degradation

The aims of this study were to investigate the effect of precise phosphorylation of Ser in GL-Hyp-GPSGEEGKR on its Fe2+ chelating capacity, and the effects and mechanisms of folic acid coupling to GL-Hyp-GPS(PO4)GEEGKR on its resistance against degradation by gastrointestinal enzymes. The results demonstrated that GL-Hyp-GPS(PO4)GEEGKR exhibited significantly enhanced Fe2+ chelating capability compared to GL-Hyp-GPSGEEGKR. This was attributed to the phosphorylation of Ser introducing more Fe2+ chelating sites. Furthermore, the results of UV-Vis, FTIR, and 1H NMR showed that folic acid has successfully coupled with GL-Hyp-GPS(PO4)GEEGKR to generate folic acid-GL-Hyp-GPS(PO4)GEEGKR. Folic acid-GL-Hyp-GPS(PO4)GEEGKR demonstrated superior resistance against degradation by gastrointestinal enzymes. This may be attributed to the coupling of folic acid altering the original zeta potential of the peptide and the steric hindrance effect of folic acid hindering the interaction between enzymes and peptide. These findings can provide valuable insights for the production of high Fe2+ chelating peptides that resist gastrointestinal enzyme degradation.

Novel Insights into Ethanol-Soluble Oyster Peptide-Zinc-Chelating Agents: Structural Characterization, Chelation Mechanism, and Potential Protection on MEHP-Induced Leydig Cells.

Numerous studies have reported that mono-(2-ethylhexyl) phthalate (MEHP) (bioactive metabolite of Di(2-ethylhexyl) phthalate) has inhibitory effects on Leydig cells. This study aims to prepare an oyster peptide-zinc complex (PEP-Zn) to alleviate MEHP-induced damage in Leydig cells. Zinc-binding peptides were obtained through the following processes: zinc-immobilized affinity chromatography (IMAC-Zn2+), liquid chromatography-mass spectrometry technology (LC-MS/MS) analysis, molecular docking, molecular dynamic simulation, and structural characterization. Then, the Zn-binding peptide (PEP) named Glu-His-Ala-Pro-Asn-His-Asp-Asn-Pro-Gly-Asp-Leu (EHAPNHDNPGDL) was identified. EHAPNHDNPGDL showed the highest zinc-chelating ability of 49.74 ± 1.44%, which was higher than that of the ethanol-soluble oyster peptides (27.50 ± 0.41%). In the EHAPNHDNPGDL-Zn complex, Asn-5, Asp-7, Asn-8, His-2, and Asp-11 played an important role in binding to the zinc ion. Additionally, EHAPNHDNPGDL-Zn was found to increase the cell viability, significantly increase the relative activity of antioxidant enzymes and testosterone content, and decrease malondialdehyde (MDA) content in MEHP-induced TM3 cells. The results also indicated that EHAPNHDNPGDL-Zn could alleviate MEHP-induced apoptosis by reducing the protein level of p53, p21, and Bax, and increasing the protein level of Bcl-2. These results indicate that the zinc-chelating peptides derived from oyster peptides could be used as a potential dietary zinc supplement.

Synthesis of metallic nanoparticles using biometabolites: mechanisms and applications.

Bio-metabolites have played a crucial role in the recent green synthesis of nanoparticles, resulting in more versatile, safer, and effective nanoparticles. Various primary and secondary metabolites, such as proteins, carbohydrates, lipids, nucleic acids, enzymes, vitamins, organic acids, alkaloids, flavonoids, and terpenes, have demonstrated strong metal reduction and stabilization properties that can be utilized to synthesize nanomaterials and influence their characters. While physical and chemical methods were previously used to synthesize these nanomaterials, their drawbacks, including high energy consumption, elevated cost, lower yield, and the use of toxic chemicals, have led to a shift towards eco-friendly, rapid, and efficient alternatives. Biomolecules act as reducing agents through deprotonation, nucleophilic reactions, transesterification reactions, ligand binding, and chelation mechanisms, which help sequester metal ions into stable metal nanoparticles (NPs). Engineered NPs have potential applications in various fields due to their optical, electronic, and magnetic properties, offering improved performance compared to bulkier counterparts. NPs can be used in medicine, food and agriculture, chemical catalysts, energy harvesting, electronics, etc. This review provides an overview of the role of primary and secondary metabolites in creating effective nanostructures and their potential applications.

Synergistic effects of boron and cadmium on the metal enrichment and cell wall immobilization capacity of Cosmosbipinnatus

Cadmium (Cd), as a heavy metal pollutant, can seriously affect plant growth and development. Boron (B), as an indispensable nutrient element, plays an important role in plant growth and cell wall (CW) synthesis. However, the physiological effects of B and Cd on plant growth and the mechanism of Cd chelation by the CW remain unclear. Here, we investigate the effect of exogenous B on Cd accumulation in CW components of Cosmos bipinnatus roots and its mechanism of Cd mitigation. Under B deficiency and single Cd (30 μM) treatments, the growth of C. bipinnatus was significantly inhibited, but the addition of exogenous B significantly increased plant biomass, which increased the Cd content in the underground parts of C. bipinnatus by 20.18% and reduced the Cd translocation factor by 22.22%. Meanwhile, application of exogenous B affected the subcellular Cd content across various Cd forms and alleviated Cd-induced oxidative stress in C. bipinnatus. Additionally, exogenous B and Cd and their mixtures affected the functional groups of the root CW, the proportion of polysaccharide components, the Cd content of polysaccharides, and the polysaccharide uronic acid content of C. bipinnatus. However, B application increased 3-deoxy-oct-2-ulosonic acid content, pectin esterase activity, low esterified pectin content, and its Cd content by 149.52%, 55.69%, 206.38%, and 150.02%, respectively, compared to Cd treatment alone. Thus, our study showed that B mitigates the toxicity of Cd to plants, revealing the effect of B on the physiological aspects of Cd tolerance in plants.

Acetone O-(2-naphthylsulfonyl) oxime alleviates the toxic effects of cadmium in maize seedlings by increasing the phenolic substance content and antioxidant system activity

The absorption of cadmium by plants largely depends on cadmium contamination in the soil. The development of phytomining and phytoremediation methods to clean cadmium-contaminated ecosystems is an urgent issue that needs to be solved. Therefore, the role of exogenous O-(2-naphthylsulfonyl)oxime (ANSO) to maize seedlings under cadmium stress was tested. The results showed that when ANSO+cadmium application was compared to cadmium, the cadmium content increased by 7.8 times, while the abscisic acid content decreased. Under cadmium stress, ANSO application did not change the relative water content, but increased the chlorophyll content. While carotenoid content increased with cadmium application, it increased further with ANSO+cadmium application. As a result of the positive effects of ANSO application on the antioxidant system under cadmium stress, hydrogen peroxide content, lipid peroxidation and proline content decreased. ANSO application under cadmium stress increased the phenolic substance content. This study shows that exogenous ANSO makes significant contributions to the protection of maize seedlings despite being under cadmium stress. It also provides important references to the fact that despite stress, the cadmium chelation mechanisms of seedlings continue to work actively to accumulate cadmium in tissues, and it has deep implications for the remediation of cadmium-polluted soils.

Revisiting biochemical pathways for lead and cadmium tolerance by domain bacteria, eukarya, and their joint action in bioremediation.

With the advent rise is in urbanization and industrialization, heavy metals (HMs) such as lead (Pb) and cadmium (Cd) contamination have increased considerably. It is among the most recalcitrant pollutants majorly affecting the biotic and abiotic components of the ecosystem like human well-being, animals, soil health, crop productivity, and diversity of prokaryotes (bacteria) and eukaryotes (plants, fungi, and algae). At higher concentrations, these metals are toxic for their growth and pose a significant environmental threat, necessitating innovative and sustainable remediation strategies. Bacteria exhibit diverse mechanisms to cope with HM exposure, including biosorption, chelation, and efflux mechanism, while fungi contribute through mycorrhizal associations and hyphal networks. Algae, especially microalgae, demonstrate effective biosorption and bioaccumulation capacities. Plants, as phytoremediators, hyperaccumulate metals, providing a nature-based approach for soil reclamation. Integration of these biological agents in combination presents opportunities for enhanced remediation efficiency. This comprehensive review aims to provide insights into joint action of prokaryotic and eukaryotic interactions in the management of HM stress in the environment.

Novel peptides with calcium-binding capacity from antler bone hydrolysate, its bioactivity on MC3T3-E1 cells, and the possible chelating mode.

In this study, peptide-calcium chelate was screened from antler bone hydrolysate, and its bioactivity on MC3T3-E1 cells and its chelating mechanism were investigated. Invitro experiments showed that peptide-calcium chelate promoted the differentiation and mineralization of MC3T3-E1 cells. Subsequently, three novel calcium-chelating peptides were obtained from antler bone hydrolysate using hydroxyapatite chromatography (HAC), Sephadex G-25 gel filtration chromatography, and reversed-phase high-performance liquid chromatography (RP-HPLC). Meanwhile, this work determined peptides' amino acid sequences as TKLGTQLQL, LETVILGLLKT, and KMVFLMDLLK based on LC-MS/MS. Then the present work prepared the three peptides, with the corresponding calcium-chelating rates being verified as 87.68 ± 2.86%, 80.72 ± 0.93%, and 67.96 ± 0.98%, respectively. Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible absorption (UV-vis) spectroscopy, X-ray diffraction (XRD), circular dichroism (CD), zeta potential, and molecular dynamics (MD) simulations were adopted to investigate the chelating mode of peptides with calcium ions. As a result, oxygen in the carboxyl group and the nitrogen in the amino group were related to calcium binding. In addition, the chelation site preferred the negatively charged carboxylate groups of Leu or Thr. The present work revealed that antler bone might be the new calcium-chelating peptide source and elucidated their positive role in osteogenesis.

Iron chelation capacity and prediction of peptide binding modes identified in California red worm hydrolysates and effects on iron bioavailability in differentiated Caco-2 cells

Metal-chelating peptides represent an alternative for overcoming iron deficiencies, a common nutritional disease affecting populations worldwide. This study explored the iron-chelating activity of California red worm hydrolysates (WH) and its fractions. WH was obtained by hydrolysis with Alcalase 2.4 L and fractionated using a ceramic membrane with molecular weight cutoff 3 kDa. Both the complete hydrolysate and its fractions were assessed for their in-vitro iron-chelating activity and their ability to improve iron bioavailability through ferritin formation by differentiated Caco-2 cells assay. Finally, peptides in the fraction with the highest activity were sequenced by LC-MS/MS analysis and molecular docking was performed to elucidate the chelation mechanism. The findings reveal that the smallest fraction (F < 3 kDa) exhibits the most potent iron-chelating activity with IC50 value like carnosine. Moreover, in intestinal-like differentiated Caco-2 cells, this fraction enhances iron bioavailability in a remarkable 77.9% in comparison to FeSO4 alone. On the other hand, the peptide SLLDDRLDEK identified in this fraction presents the lowest value of affinity energy (−1.5 kcal/mol) and exhibits specific interactions with iron, allowing iron ions to be trapped within its structure. These results underscore the potential of F < 3 kDa fractions from WH as promising candidates for increasing iron bioavailability and addressing iron deficiency and related health concerns.

Calcium carbonate/ε-poly(lysine) hybrid microparticles for uranium seawater extraction: an eco-compatible emergency response to marine nuclear disasters

During the past decade, a large variety of materials dedicated to uranium seawater extraction has been developed for harvesting purposes. Yet, materials especially designed for decontamination following nuclear accidents are scarce and eco-friendly ones even rarer. In this study, hybrid microparticles made of biocompatible calcium carbonate and ε-poly(lysine) are used as efficient U sorbent in seawater. Their eco-friendly nature makes them interesting for both harvesting and on-site immobilization of radionuclides, also accounting their ability to settle in the seabed with limited impact on eco-systems. The material shows excellent U extraction capability in contaminated seawater ([U] = 10 ppm) with removal rate R of 87.7 % and extraction capacity of 513 mg per g of ε-poly(lysine) and remains efficient in natural condition ([U] = 2.8 ppb) with R = 39.8 %. In addition, the sorbent has a remarkable selectivity toward U versus V in U contaminated seawater as well as a significant affinity for Sr2+. DFT and XPS analyses revealed that U is adsorbed to ε-poly(lysine) via a chelation mechanism that involves amide and amine groups of lysine. Lability of the formed coordination complex allows easy recovery of captured U by contact with NaHCO3 desorbing solution, ensuring recyclability of the material.

Biochar modified by ammonium pyrrolidine dithiocarbamate for high selective adsorption of copper in wastewater

Biochar application in wastewater purification is extremely appealing. Although heteropolysaccharides like Gum Seyal biochar (BC GS500) display great surface area and porosity, the adsorption capacity for Cu (II) was relatively low due to the week-binding surface functional groups. In this work, an innovative modification with the chelating agent ammonium pyrrolidine dithiocarbamate (APDC) capable of selectively and effectively adsorbing Cu (II) was conducted. Gum Seyal biochar was grafted with pyrrolidine dithiocarbamate (C5H8NS2–), amine (–NH2), and imine (–NH) groups using APDC based on the “hard and soft acids and bases theory” (HSAB). Batch studies, along with characterization (FITR, XPS, and SEM-EDS), molecular electrostatic potential (MEP) mapping, and density functional theory (DFT) calculations, were implemented to investigate the adsorption performance and mechanism responsible for selectively adsorptive Cu (II) removal. It was found that Cu (II) adsorption by modified biochar occurred endothermically and spontaneously. The adsorption data at pH 5 matched the pseudo-second-order kinetic model and the Langmuir isotherm (211.24 mg/g). DFT calculations show that modified biochar selectively binds Cu (II) superior to common ions such as Mg (II) and Ca (II) through a unique chelating mechanism. Their performance in real electroplating wastewater was investigated, and the production cost was estimated. It was concluded that the modified biochar (BC APDC) could have high applicable potential for Cu (II)-laden wastewater purification.

Chelation Protection for Zinc Anode of Aqueous Batteries

AbstractThis mini‐review comprehensively outlines the latest advancements in protecting zinc anodes in zinc‐ion batteries (ZIBs) through chelation mechanisms. Chelation involves the coordination of ligands with Zn2+, offering promising strategies to address challenges such as dendrite formation and hydrogen evolution reactions. However, there is a lack of comprehensive and unified evaluation of chelation‘s protective effect on the zinc anode, which hinders a thorough assessment of chelation‘s effectiveness. Recent studies have demonstrated the excellent protective performance of chelation in altering solvation structures, modifying SEI structures, and selectively adsorbing species on the zinc anode. Furthermore, while chelation demonstrates significant benefits for the zinc anode, its impact on cathode materials must also be considered. Proper selection of chelation strengths and compatible cathode materials is essential for overall battery performance. Future research directions include exploring the effects of different ligands and coordination numbers on battery performance and extending chelation strategies to other secondary metal batteries. Understanding and optimizing chelation mechanisms are critical for advancing the development of high‐performance ZIBs and other metal‐ion battery technologies.

Isolation, identification, and chelation mechanism of ferrous-chelating peptide from peanut protein hydrolysate.

Peanut peptides can chelate iron but their chelation mechanism remains unclear. The purpose of this study is to separate peanut ferrous-chelating peptides and explore the chelation mechanism of peanut peptides with iron. Peanut peptide component F-122, which had a higher chelation rate, was separated using ultrafiltration, gel filtration chromatography, and ion exchange chromatography, achieving a ferrous chelation rate of 90.7%. Six peptide segments were screened and their amino acid sequences were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Spectral analysis confirmed that the chelation between peanut peptides and ferrous ions occurred and a new substance was formed. Molecular docking simulation indicated that the amino acids in peanut peptides involved in the chelating reaction were glutamic acid, arginine, glycine, threonine, phenylalanine, and lysine. The binding sites included the main chain oxygen atom, side chain oxygen atom, and carboxyl oxygen atom of amino acid. The isolated peanut peptide had a higher ferrous-chelation rate. The chelating mechanism of peanut peptide with ferrous ion was elucidated. This study provides a theoretical basis for the development of new peptide-ferrous preparations. © 2024 Society of Chemical Industry.

Coupled physicochemical dual-crosslinking Ti3C2Tx composite aerogels for the selective adsorption of gallium ions in acid fly ash leaching

Herein, in order to extract Ga3+ from acid fly ash leaching, we propose a functionalized Ti3C2Tx-based MXene composite aerogel adsorbent for Ga3+ adsorption. The prepared physicochemical dual-crosslinking network aerogel MPHG-40 possesses good Ga3+ adsorption performance (132.52 mg g−1) at the pH of 3 and Ga3+ initial concentration of 50 mg L−1 within 6 h. After five adsorption-desorption cycles, the material shows good mass retention and a 95.65 % retention of its initial adsorption capacity, compared to most reported adsorbents. The optimized adsorbent realized good selective adsorption of Ga3+ against Cu2+, Zn2+, Fe3+, and Al3+ in a simulated acid fly ash leaching with the selective coefficient of 8.63, 96.10, 4.49, and 28.30, respectively. The adsorption may comply with a combined mechanism of physical adsorption, electrostatic interactions, ion-exchange mechanism, and ligand chelation, dominated by chemical adsorption, as identified by theoretical calculations based on density functional theory and experimental data. The three-dimensional solid adsorbent constructed in this study provides a new strategy for selective adsorption of Ga3+, making it possible to be applied to solid waste utilization of fly ash.

Digestion and absorption characteristics of iron-chelating silver carp scale collagen peptide and insights into their chelation mechanism

Iron deficiency is widespread throughout the world, supplementing sufficient iron or improving the bioavailability of iron is the fundamental strategy to solve the problem of iron scarcity. Herein, we explored a new form of iron supplement, iron chelates of silver carp scales (SCSCP-Fe) were prepared from collagen peptide of silver carp scales (SCSCP) and FeCl2·4H2O, the effects of external environment and simulated gastrointestinal digestive environment on the stability of SCSCP-Fe and the structural changes of peptide iron chelates during digestion were investigated. The results of in vitro iron absorption promotion showed that the iron bioavailability of SCSCP-Fe was higher than that of FeSO4. Two potential high iron chelating peptides DTSGGYDEY (DY) and LQGSNEIEIR (LR) were screened and synthesized from the SCSCP sequence by molecular dynamics and LC-MS/MS techniques. The FTIR results displayed that the binding sites of DY and LR for Fe2+ were the carboxyl group, the amino group, and the nitrogen atom on the amide group on the peptide. ITC results indicated that the chelation reactions of DY and LR with Fe2+ were mainly dominated by electrostatic interactions, forming chelates in stoichiometric ratios of 1:2 and 1:1, respectively. Both DY and LR had a certain ability to promote iron absorption. The transport of DY-Fe chelate may be a combination of the three pathways: PepT1 vector pathway, cell bypass, and endocytosis, while LR-Fe chelate was dominated by bivalent metal ion transporters. This study is expected to provide theoretical reference and technical support for the high-value utilization of silver carp scales and the development of novel iron supplements.

Molecular Basis of Energy Crops Functioning in Bioremediation of Heavy Metal Pollution

Heavy metal pollution is a gradually growing environmental issue that hinders the growth and development of plants, and also destabilizes soil. Consequently, eco-friendly phytoremediation methods have gained traction, with energy crops emerging as a particularly effective solution. Energy crops not only provide high-quality plant materials for detoxification and remediation of heavy metal pollution, but also possess energy properties conducive to biofuel production. Therefore, this paper delves into the tolerance mechanism of energy crops towards heavy metal toxicity, elucidating processes such as root complex-mediated inhibition of metal migration and response to reactive oxygen species (ROS) through heavy metal-related proteins, enzyme systems, reactive nitrogen species (RNS), and hormones. Moreover, it summarizes the heavy metals remediation mechanisms of energy crops, including uptake, translocation, chelation, immobilization, and sequestration. This paper explores applications of energy crops in heavy metal pollution remediation, emphasizing the methods for efficient biochar remediation and biofuel generation. Furthermore, potential challenges in using energy crops for heavy metal pollution remediation are outlined. By systematically examining the function mechanisms and prospective applications of energy crops in heavy metal pollution bioremediation, this paper serves as a valuable reference for both research and practical implementation in this field.

A novel antioxidant iron-chelating peptide from yak skin: analysis of the chelating mechanism and digestion stability in vitro.

The global prevalence of iron deficiency has posed significant public health risks. Animal-derived collagen peptides have been recognized for their potent metal ion-chelating capabilities, which can greatly enhance the bioavailability of iron. Yak skins, typically discarded during production and processing, serve as a valuable resource. Based on yak skin collagen peptide (YSP), we have developed a novel iron-chelating peptide: yak skin collagen iron-chelating peptide (YSP-Fe). The maximum level of iron chelation of YSP-Fe achieved was 42.72 ± 0.65 mg g-1. Structural analysis indicated that YSP-Fe was primarily formed from amino, carboxyl and carbonyl groups combined with ferrous ions. Through examination of the amino acid composition, molecular docking and peptide sequence identification, it was determined that Gly, Asp and Arg played crucial roles in the chelation of ferrous ions by YSP. Furthermore, YSP-Fe was more stable in simulated gastrointestinal digestion compared to FeSO4. YSP-Fe demonstrated dual benefits of iron supplementation and antioxidant effects. These significant findings provide a foundation for the development of novel iron supplements and the effective utilization of yak skin as a valuable resource. © 2024 Society of Chemical Industry.

Molecular Dynamics Simulation of the Interaction within the Carboxymethyl Cellulose-Modified Montmorillonite Lamellae at Aggressive CuCl2 Concentrations.

To elucidate the degradation mechanism of the CMC-modified MMT composite at aggressive Cu2+ concentrations, large scale molecular dynamics simulation was conducted for CuCl2 concentrations ranging from 0 to 800 mM. Both CMC and MMT followed the Langmuir isotherm for Cu2+ adsorption, and the adsorption capacity of CMC (8.75 mmol/g) was much higher than that of MMT (0.83 mmol/g). Despite the CMC mass ratio being only 4.1%, it adsorbed up to 34.3% of the total adsorbed Cu2+. The Cu2+ attraction ability hierarchy of oxygen-containing functional groups in the CMC is as follows: carboxylic oxygens > alcoholic oxygens > carbinolic oxygens > bridging oxygens > glucose oxygens. Carboxyls were the most effective in chelating and complexing with Cu2+, and they could be intentionally added in artificially synthesized polymer-MMT composites for Cu2+ containment. Formation of the Cu2+ cation bridge between CMC and MMT at aggressive CuCl2 concentrations contributed to the transition of CMC density distribution from unimodality to bimodality and enhanced resistance of polymer elution. As the CuCl2 concentration increased, the stoichiometric ratio between the chelated Cu2+ and carboxylic oxygens increased from 1:2 to 1:1, suggesting the evolution of the Cu2+ chelation mechanism.

2,5-Furandicarboxylic acid-based porous polyamides: Preparation and adsorption efficiency for Hg2+

From 2,5-furan dicarboxylic acid, a robust biomass platform molecule, furan-based porous polyamide (FPPA-1 and -2) was synthesized and applied for the removal of Hg2+ from water. FPPA-1 and -2 were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The effects of pH, dosage, contact time, temperature and concentration on the adsorption of Hg2+ were systematically investigated. The pseudo-second-order kinetics and the Langmuir isotherm model are in the best agreement with the experimental data, and the maximum adsorption capacity is 462 mg g−1. Thermodynamically, the adsorption of Hg2+ is a spontaneous adsorption process. There was no significant loss of performance during five regeneration cycles. In combination with the experimental data and density functional theory (DFT) calculation, the chelation mechanism of Hg2+ was demonstrated. Our study offers new perspectives for the removal of Hg2+ from wastewater.

Coumarin-Modified Starch Fluorescent Nanoparticles as Sensor of Fe3+ and Zn2+ ions Utilizing Dynamic Quenching and Chelation Mechanisms.

Zinc and iron are two essential trace minerals that play a pivotal role in maintaining optimal health and well-being in the human body. Despite being required in relatively small quantities, their significance can be understated as they participate in a wide array of critical physiological processes such as oxygen transport, DNA synthesis, controlling nutrient availability, etc. Understanding the distribution and behavior of these ions in natural water bodies is essential for assessing water quality, studying ecological processes, and managing environmental impacts. In this study, we have developed a dual fluorescence probe using starch which was functionalized with coumarin derivatives, for efficient detection of Fe3+ and Zn2+ ions. This structure led a self-assembled starch/coumarin (SC) fluorescent nanoparticles with strong fluorescence intensity under ultraviolet light (365nm). The quenching effect of Fe3+ on the SC fluorescent probe enabled efficient specific detection of Fe3+. Furthermore, Zn2+ ions increased fluorescence intensity of coumarin compounds (λemission = 459). This phenomenon occurs when the coumarin compound forms a complex or interacts with the zinc ion, resulting in enhanced fluorescence emission. In summary, the developed fluorescent probe offered a promising approach for sensitive and specific detection of iron and zinc ions in aqueous solutions.

Investigating the Mechanism of Aluminum Fluoride Chelation.

Aluminum fluoride (AlF) complexes have been used over the past decade to incorporate [18F]fluoride into large biomolecules in a highly selective fashion by using relatively facile conditions. However, despite their widespread usage, there are a large number of variations in the reaction conditions, without a definitive discussion provided on the mechanism to understand how these changes would alter the end result. Herein, we report a detailed mechanistic investigation of the reaction, using a mixture of theoretical studies, fluorine-19 and fluorine-18 chemistry, and the consequences it has on the efficient clinical translation of AlF-containing imaging agents.