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Ecotoxicology and Environmental Safety Mar 2024Deferiprone, generally, is considered an important chelating agent for Fe overload. From a literature data analysis, a lack of information on the interaction of this...
Deferiprone, generally, is considered an important chelating agent for Fe overload. From a literature data analysis, a lack of information on the interaction of this molecule toward a series of metal cations emerged, inducing to fill out the topic. The complexing ability of deferiprone toward Ca, Mg, Cd and Pb was studied by potentiometry and H NMR spectroscopy, in KCl aqueous solutions at different ionic strength values (0.1 ≤ I/mol dm ≤ 1.0) and T = 298.15 K. The same speciation model featured by the ML, ML, ML and ML(OH) (M = metal and L = deferiprone or DFP) species was obtained for Cd and Pb; the formation constants calculated at infinite dilution are: logβ = 7.23±0.02, 12.47±0.03, 16.70±0.04, and -2.53±0.04, respectively for Cd and 9.91±0.01, 15.99±0.02, 19.93±0.05 and 0.99±0.02 for Pb. Only two species, namely ML and ML, were determined for Ca and Mg, whose formation constants at infinite dilution are respectively: 3.72±0.01 and 6.50±0.02, for the first one, 5.31±0.01 and 9.58±0.01, for the second. The ligand sequestering ability and affinity toward M were evaluated by determining the pL and pM parameters at different pHs and ionic strengths. The results suggest that deferiprone has the best complexing and sequestering ability toward Pb, followed by Cd, Mg and Ca, respectively. H NMR studies confirmed the DFP affinity for Cd and Pb, and in combination with DFT calculations showed that metal cations are bound to the hydroxo-oxo moiety of the pyridinone ring. The data reported in this study provide information on the possible employment of a small molecule like deferiprone, as a chelating and sequestering agent for Pb accumulation or overload from environmental and biological matrices.
Topics: Deferiprone; Cadmium; Lead; Cations; Models, Theoretical; Chelating Agents
PubMed: 38295733
DOI: 10.1016/j.ecoenv.2024.116027 -
Journal of Inorganic Biochemistry Aug 2023Desferoxamine (DFO) is currently the golden standard chelator for Zr, a promising nuclide for positron emission tomography imaging (PET). The natural siderophore DFO had...
Desferoxamine (DFO) is currently the golden standard chelator for Zr, a promising nuclide for positron emission tomography imaging (PET). The natural siderophore DFO had previously been conjugated with fluorophores to obtain Fe(III) sensing molecules. In this study, a fluorescent coumarin derivative of DFO (DFOC) has been prepared and characterized (potentiometry, UV-Vis spectroscopy) for what concerns its protonation and metal coordination properties towards PET-relevant ions (Cu(II), Zr(IV)), evidencing strong similarity with pristine DFO. Retention of DFOC fluorescence emission upon metal binding has been checked (fluorescence spectrophotometry), as it would - and does - allow for optical (fluorescent) imaging, thus unlocking bimodal (PET/fluorescence) imaging for Zr(IV) tracers. Crystal violet and MTT assays on NIH-3 T3 fibroblasts and MDA-MB 231 mammary adenocarcinoma cell lines demonstrated, respectively, no cytotoxicity nor metabolic impairment at usual radiodiagnostic concentrations of ZrDFOC. Clonogenic colony-forming assay performed on X-irradiated MDA-MB 231 cells showed no interference of ZrDFOC with radiosensitivity. Morphological biodistribution (confocal fluorescence, transmission electron microscopy) assays on the same cells suggested internalization of the complex through endocytosis. Overall, these results support fluorophore-tagged DFO as a suitable option to achieve dual imaging (PET/fluorescence) probes based on Zr.
Topics: Deferoxamine; Radioisotopes; Tissue Distribution; Ferric Compounds; Fluorescence; Positron-Emission Tomography; Chelating Agents; Coumarins; Cell Line, Tumor
PubMed: 37229819
DOI: 10.1016/j.jinorgbio.2023.112259 -
Scientific Reports Oct 2023The complexation of trivalent lanthanides and minor actinides (Am, Cm, and Cf) by the acyclic aminopolycarboxylate chelators...
The complexation of trivalent lanthanides and minor actinides (Am, Cm, and Cf) by the acyclic aminopolycarboxylate chelators 6,6'-((ethane-1,2-diylbis-((carboxymethyl)azanediyl))bis-(methylene))dipicolinic acid (Hoctapa) and 6,6'-((((4-(1-(2-(2-(2-hydroxyethoxy)ethoxy)ethyl)-1H-1,2,3-triazol-4-yl)pyridine-2,6-diyl)bis-(methylene))bis-((carboxymethyl)azanediyl))bis-(methylene)) dipicolinic acid (Hpypa-peg) were studied using potentiometry, spectroscopy, competitive complexation liquid-liquid extraction, and ab initio molecular dynamics simulations. Two studied reagents are strong multidentate chelators, well-suited for applications seeking radiometal coordination for in-vivo delivery and f-element isolation. The previously reported Hoctapa forms a compact coordination packet, while Hpypa-peg is less sterically constrained due to the presence of central pyridine ring. The solubility of Hoctapa is limited in a non-complexing high ionic strength perchlorate media. However, the introduction of a polyethylene glycol group in Hpypa-peg increased the solubility without influencing its ability to complex the lanthanides and minor actinides in solution.
PubMed: 37857726
DOI: 10.1038/s41598-023-44106-6 -
Chemistry & Biodiversity Jun 2024Numerous chemical pesticides were employed for a long time to manage pests, but their uncontrolled application harmed the health and the environment. Accurately... (Review)
Review
Numerous chemical pesticides were employed for a long time to manage pests, but their uncontrolled application harmed the health and the environment. Accurately quantifying pesticide residues is essential for risk evaluation and regulatory purposes. Numerous analytical methods have been developed and utilized to achieve sensitive and specific detection of pesticides in intricate sampl es like water, soil, food, and air. Electrochemical sensors based on amperometry, potentiometry, or impedance spectroscopy offer portable, rapid, and sensitive detection suitable for on-site analysis. This study examines the potential of electrochemical sensors for the accurate evaluation of various effects of pesticides. Emphasizing the use of Graphene (GR), Graphene Oxide (GO), Reduced Graphene Oxide (rGO), and Graphdiyne composites, the study highlights their enhanced performance in pesticide sensing by stating the account of many actual sensors that have been made for specific pesticides. Computational studies provide valuable insights into the adsorption kinetics, binding energies, and electronic properties of pesticide-graphene complexes, guiding the design and optimization of graphene-based sensors with improved performance. Furthermore, the discussion extends to the emerging field of biopesticides. While the GR/GO/rGO based sensors hold immense future prospects, and their existing limitations have also been discussed, which need to be solved with future research.
Topics: Graphite; Pesticides; Electrochemical Techniques
PubMed: 38578653
DOI: 10.1002/cbdv.202302080 -
Sensors (Basel, Switzerland) Sep 2023For the first time, a prototype of a portable device for the potentiometric determination of antioxidant capacity based on a new measurement principle is proposed. A...
For the first time, a prototype of a portable device for the potentiometric determination of antioxidant capacity based on a new measurement principle is proposed. A feature of the approach is the use of an electrochemical microcell with separated spaces and two identical electrodes with immobilized reagents. An antioxidant solution is introduced into one half-cell, and the antioxidants interact with the reagents. The other half-cell contains only reagents. The potential difference between the electrodes is due to the change in the ratio of the oxidized and reduced form of the reagents, which occurs as a result of the reaction with the antioxidants in one of the half-cells and is related to their concentration. The range of linearity of the microcell with immobilized reagents is 40-4000 μM-eq, and the limit of detection is 20 μM-eq. The device was successfully tested in the analysis of standard antioxidant solutions. The recoveries were (92-113)%, and the relative standard deviation did not exceed 15%. A good correlation was found between the data obtained by the approach and the potentiometric method in a macrocell for fruit juice analysis. Pearson's coefficient for the obtained experimental data was 0.9955. The proposed portable device is promising and can be used in field conditions.
Topics: Antioxidants; Potentiometry; Electrodes
PubMed: 37765901
DOI: 10.3390/s23187845 -
Journal of Inorganic Biochemistry Sep 2024Morin (MRN), an intriguing bioflavonol, has received increasing interest for its antioxidant properties, as have its metal complexes (M-MRN). Understanding their...
Morin (MRN), an intriguing bioflavonol, has received increasing interest for its antioxidant properties, as have its metal complexes (M-MRN). Understanding their antioxidant behavior is critical to assess their pharmaceutical, nutraceutical potential, and therapeutic impact in the design of advanced antioxidant drugs. To this end, knowing the speciation of different H-MRN and M-MRN is pivotal to understand and compare their antioxidant ability. In this work, the protonation constant values of MRN under physiological ionic strength and temperature conditions (I = 0.15 mol L and t = 37 °C), determined by UV-vis spectrophotometric titrations, are introduced. Thus, a reliable speciation model on H-MRN species in aqueous solution is presented, which exhibits five stable forms depending on pH, supplemented by quantum-mechanical calculations useful to determine the proton affinities of each functional group and corresponding deprotonation order. Furthermore, potentiometry and UV-vis spectrophotometry have been exploited to determine the thermodynamic interaction parameters of MRN with different metal cations (Mg, Mn, Zn, Al). The antioxidant ability of H-MRN and M-MRN has been evaluated by the 2,2'-diphenyl-1-benzopyran-4-one (DPPH) method, and the Zn-MRN system has proven to afford the most potent antioxidant effect. Ab initio molecular dynamics simulations of M-MRN species at all possible chelation sites and under explicit water solvation allowed for the fine characterization not only of the metal chelation modalities of MRN in explicit water, but also of the role played by the local water environment around the metal cations. Those microscopic patterns reveal to be informative on the different antioxidant capabilities recorded experimentally.
Topics: Flavonoids; Antioxidants; Coordination Complexes; Zinc; Magnesium; Aluminum; Manganese; Thermodynamics; Flavones
PubMed: 38852294
DOI: 10.1016/j.jinorgbio.2024.112635 -
Materials (Basel, Switzerland) Dec 2023Tin determination allows for the monitoring of pollution and assessment of the impact of human activities on the environment. The determination of tin in the environment... (Review)
Review
Tin determination allows for the monitoring of pollution and assessment of the impact of human activities on the environment. The determination of tin in the environment is crucial for the protection of human health and ecosystems, and for maintaining sustainability. Tin can be released into the environment from various sources, such as industry, transportation, and electronic waste. The concentration of tin in the environment can be determined by different analytical methods, depending on the form of tin present and the purpose of the analysis. The choice of an appropriate method depends on the type of sample, concentration levels, and the available instrumentation. In this paper, we have carried out a literature review of electrochemical methods for the determination of tin. Electrochemical methods of analysis such as polarography, voltammetry, and potentiometry can be used for the determination of tin in various environmental samples, as well as in metal alloys. The detection limits and linearity ranges obtained for the determination of tin by different electrochemical techniques are collected and presented. The influence of the choice of base electrolyte and working electrode on signals is also presented. Practical applications of the developed tin determination methods in analyzing real samples are also summarized.
PubMed: 38138688
DOI: 10.3390/ma16247545 -
Chemical Science Aug 2023Although metal-organic framework (MOF) photocatalysts have become ubiquitous, basic aspects of their photoredox mechanisms remain elusive. Nanosizing MOFs enables...
Although metal-organic framework (MOF) photocatalysts have become ubiquitous, basic aspects of their photoredox mechanisms remain elusive. Nanosizing MOFs enables solution-state techniques to probe size-dependent properties and molecular reactivity, but few MOFs have been prepared as nanoparticles (nanoMOFs) with sufficiently small sizes. Here, we report a rapid reflux-based synthesis of the photoredox-active MOF TiO(OH)(terephthalate) (MIL-125) to achieve diameters below 30 nm in less than 2 hours. Whereas MOFs generally require analysis by solid-state techniques, sub-30 nm diameters ensure colloidal stability for weeks and minimal light scattering, permitting analysis by solution-state methods. Optical absorption and photoluminescence spectra of free-standing colloids provide direct evidence that the photoredox chemistry of MIL-125 involves Ti trapping and charge accumulation onto the Ti-oxo clusters. Solution-state potentiometry collected during the photochemical process also allows simultaneous measurement of MOF Fermi-level energies . Finally, by leveraging the solution-processability of these nanoparticles, we demonstrate facile preparation of mixed-matrix membranes with high MOF loadings that retain the reversible photochromism. Taken together, these results demonstrate the feasibility of a rapid nanoMOF synthesis and fabrication of a photoactive membrane, and the fundamental insights they offer into heterogeneous photoredox chemistry.
PubMed: 37621428
DOI: 10.1039/d3sc02257a -
Critical Reviews in Analytical Chemistry Apr 2024Electrochemical sensors have been the subject of much research and development as of late, with several publications detailing new designs boasting enhanced performance... (Review)
Review
Electrochemical sensors have been the subject of much research and development as of late, with several publications detailing new designs boasting enhanced performance metrics. That is, without a doubt, because such sensors stand out from other analytical tools thanks to their excellent analytical characteristics, low cost, and ease of use. Their progress has shown a trend toward seeking out novel useful nano structure materials. A variety of nanostructure metal oxides have been utilized in the creation of potentiometric sensors, which are the subject of this article. For screen-printed pH sensors, metal oxides have been utilized as sensing layers due to their mixed ion-electron conductivity and as paste-ion-selective electrode components and in solid-contact electrodes. Further significant uses include solid-contact layers. All the metal oxide uses mentioned are within the purview of this article. Nanoscale metal oxides have several potential uses in the potentiometry method, and this paper summarizes such uses, including hybrid materials and single-component layers. Potentiometric sensors with outstanding analytical properties can be manufactured entirely from metal oxides. These novel sensors outperform the more traditional, conventional electrodes in terms of useful characteristics. In this review, we looked at the potentiometric analytical properties of different building solutions with various nanoscale metal oxides.
PubMed: 38593048
DOI: 10.1080/10408347.2024.2337876 -
Sensors (Basel, Switzerland) Nov 2023In the present work, potentiometric sensors with polymer membranes used for chlorhexidine (CHXD) determination were developed. The polymer membranes were plasticized...
In the present work, potentiometric sensors with polymer membranes used for chlorhexidine (CHXD) determination were developed. The polymer membranes were plasticized with bis(2-ethylheksyl)sebacate (DOS) or 2-nitrophenyloctyl ether (-NPOE). The active compounds used in the membrane were cyclodextrins, crown ethers, and ion exchangers. The best-constructed electrode was based on neutral heptakis(2,3,6-tri-O-benzoyl)--cyclodextrin with lipophilic salt (KTpClBP)-potassium tetrakis(4-chlorophenyl) borate-dissolved in plasticizer, DOS. The presented electrode is characterized by an average cationic slope of 30.9 ± 2.9 mV decade within a linear range of 1 × 10 to 1 × 10 mol × L, while the value of the correlation coefficient is 0.9970 ± 0.0026. The response time was about 5 s when increasing the sample concentration and about 10 s when diluting the sample. The electrode potential is independent of the pH within a range of 4.0-9.5. The polymeric membrane sensor was successfully applied for assays of chlorhexidine digluconate in pure samples and pharmaceutical samples. The relative error from three replicate measurements was determined to be 1.1%. and the accuracy was RSD = 0.3-1.1%.
Topics: Chlorhexidine; Membranes, Artificial; Electrodes; Potentiometry; Polymers; Hydrogen-Ion Concentration
PubMed: 38067881
DOI: 10.3390/s23239508