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ACS Sensors Nov 2023Fluoride ions are highly relevant in environmental and biological sciences, and there is a very limited number of established fluoride chemical sensors. Previous...
Fluoride ions are highly relevant in environmental and biological sciences, and there is a very limited number of established fluoride chemical sensors. Previous fluoride-selective optodes were demonstrated with metal-porphyrin as the ionophore and required a chromoionophore for optical signal transduction. We demonstrate here novel optical fluoride sensing with nano-optodes containing an aluminum-phthalocyanine complex (AlClPc) as the single active sensing component, simplifying the conventional ion-selective optodes approach. The fluoride nano-optodes were interrogated in the absorbance and fluorescence modes in the near-infrared region, with absorption around 725 nm and emission peaks at 720 and 800 nm, respectively. The nano-optodes exhibited a lower detection limit around 0.1 μM and good selectivity over a range of common anions including ClO, Cl, Br, I, SO, NO, and AcO. Furthermore, the nano-optodes were physically entrapped in agarose hydrogels to allow distance-based point-of-care testing (POCT) applications. The 3D networks of the agarose hydrogel were able to filter off large particulates in the samples without stopping fluoride ions to reach the nano-optodes. The fluoride concentrations in real samples including river water, mineral water, and groundwater were successfully determined with the distance-based sensing hydrogel, and the results agreed well with those from commercial fluoride electrodes. Therefore, the results in this work lay the groundwork for the optical detection of fluoride in environmental samples without very sophisticated sample manipulation.
Topics: Fluorides; Aluminum; Hydrogels; Sepharose
PubMed: 37963263
DOI: 10.1021/acssensors.3c01848 -
Journal of the American Chemical Society Nov 2023Tandem mass spectrometry (MS/MS) using fragmentation has become one of the most effective methods for gaining sequence and structural information on biomolecules....
Tandem mass spectrometry (MS/MS) using fragmentation has become one of the most effective methods for gaining sequence and structural information on biomolecules. Ion/ion reactions are competitive reactions, where either proton transfer (PT) or electron transfer (ET) can occur from interactions between multiply charged cations and singly charged anions. Utilizing ion/ion reactions with fluoranthene has offered a unique method of fragment formation for the structural elucidation of biomolecules. Fluoranthene is considered an ideal anion reagent because it selectively causes electron-transfer dissociation (ETD) and minimizes PT when interacting with peptides. However, limited investigations have sought to understand how fluoranthene─the primary, commercially available anion reagent─interacts with other biomolecules. Here, we apply deuterium labeling to investigate ion/ion reaction mechanisms between fluoranthene and divalent, metal-adducted carbohydrates (Ca, Mg, Co, and Ni). Deuterium labeling of carbohydrates allowed us to observe evidence of hydrogen/deuterium exchange (HDX) occurring after ion/ion dissociation reactions. The extent of deuterium loss is dependent on several factors, including the physical properties of the metal ion and the fragment structure. Based on the deuterium labeling data, we have proposed ETD, PTD, and intermolecular PT─also described as HDX─mechanisms. This research provides a fundamental perspective of ion/ion and ion/molecule reaction mechanisms and illustrates properties that impact ion/ion and ion/molecule reactions for carbohydrates. Together, this could improve the capability to distinguish complex and heterogeneous biomolecules, such as carbohydrates.
Topics: Deuterium; Tandem Mass Spectrometry; Protons; Carbohydrates; Anions; Deuterium Exchange Measurement
PubMed: 37874934
DOI: 10.1021/jacs.3c05793 -
Advanced Materials (Deerfield Beach,... Jan 2024Polyoxometalates (POMs) are known antitumoral, antibacterial, antiviral, and anticancer agents and considered as next-generation metallodrugs. Herein, a new biological...
Polyoxometalates (POMs) are known antitumoral, antibacterial, antiviral, and anticancer agents and considered as next-generation metallodrugs. Herein, a new biological functionality in neutral physiological media, where selected mixed-metal POMs are sufficiently stable and able to affect membrane transport of impermeable, hydrophilic, and cationic peptides (heptaarginine, heptalysine, protamine, and polyarginine) is reported. The uptake is observed in both, model membranes as well as cells, and attributed to the superchaotropic properties of the polyoxoanions. In view of the structural diversity of POMs these findings pave the way toward their biomedical application in drug delivery or for cell-biological uptake studies with biological effector molecules or staining agents.
Topics: Anions; Metals; Antineoplastic Agents
PubMed: 37943506
DOI: 10.1002/adma.202309219 -
Physical Chemistry Chemical Physics :... Nov 2023Flavin mononucleotide (FMN) is a highly versatile biological chromophore involved in a range of biochemical pathways including blue-light sensing proteins and the...
Flavin mononucleotide (FMN) is a highly versatile biological chromophore involved in a range of biochemical pathways including blue-light sensing proteins and the control of circadian rhythms. Questions exist about the effect of local amino acids on the electronic properties and photophysics of the chromophore. Using gas-phase anion laser photodissociation spectroscopy, we have measured the intrinsic electronic spectroscopy (3.1-5.7 eV) and accompanying photodissociative decay pathways of the native deprotonated form of FMN, [FMN-H] complexed with the amino acids tryptophan (TRP) and glutamic acid (GLU), [FMN-H]·TRP and [FMN-H]·GLU, to investigate the extent to which these amino acids perturb the electronic properties and photodynamics of the [FMN-H] chromophore. The overall photodepletion profiles of [FMN-H]·TRP and [FMN-H]·GLU are similar to that of the monomer, revealing that amino acid complexation occurs without significant spectral shifting of the [FMN-H] electronic excitations over this region. Both [FMN-H]·TRP and [FMN-H]·GLU are observed to decay by non-statistical photodecay pathways, although the behaviour of [FMN-H]·TRP is closer to statistical fragmentation. Long-lived FMN excited states (triplet) are therefore relatively quenched when TRP binds to [FMN-H]. Importantly, we find that [FMN-H], [FMN-H]·TRP and [FMN-H]·GLU all decay predominantly electron detachment following photoexcitation of the flavin chromophore, with amino acid complexation appearing not to inhibit this decay channel. The strong propensity for electron detachment is attributed to excited-state proton transfer within FMN, with proton transfer from a ribose alcohol to the phosphate preceding electron detachment.
Topics: Protons; Tryptophan; Flavin Mononucleotide; Glutamic Acid; Anions
PubMed: 37934009
DOI: 10.1039/d3cp04359b -
Environmental Technology Oct 2023The effects of two microelements, zinc and copper, on the aerobic co-metabolic removal of trichloroethylene (10 mg/L) by the isolate were investigated. The strain was...
The effects of two microelements, zinc and copper, on the aerobic co-metabolic removal of trichloroethylene (10 mg/L) by the isolate were investigated. The strain was previously isolated from a petroleum-contaminated site using toluene (150 mg/L) as substrate. Different concentrations (1, 10 and 100 mg/L) of microelements provided with SO and Cl were tested. The results showed the supplement of Zn and Cu at the low concentration (1 mg/L) significantly enhanced cell growth. The removal efficiencies for toluene and trichloroethylene were also enhanced at the low concentration (1 mg/L) of Zn and Cu. Compared to the control without zinc supplement, higher concentrations of zinc (10 and 100 mg/L) enhanced the removal efficiencies for both toluene and trichloroethylene in the first three days but showed some inhibitory effect afterward. However, the higher concentrations of Cu (10 and 100 mg/L) always showed inhibitory to the toluene removal while showing inhibitory to the TCE removal after three days. For both Zn and Cu, the anions SO and Cl did not show significant difference in their effects on the toluene removal. A possible mechanism for Zn and Cu to enhance the removal of toluene and trichloroethylene would be their involvement in toluene oxygenase-based transformation processes. In addition, high concentrations of Zn and Cu ions could be removed from the liquid by the cells accordingly. The results imply a potential of supplementing low concentrations of zinc and copper to enhance bioremediation of the sites co-contaminated with toluene and trichloroethylene.
Topics: Trichloroethylene; Copper; Water; Zinc; Toluene; Biodegradation, Environmental
PubMed: 35451932
DOI: 10.1080/09593330.2022.2069518 -
Journal of Aerosol Medicine and... Apr 2024Hyperosmolar aerosols appear to promote or suppress upper airway dysfunction caused by dehydration in a composition-dependent manner. We sought to explore this...
Hyperosmolar aerosols appear to promote or suppress upper airway dysfunction caused by dehydration in a composition-dependent manner. We sought to explore this composition dependence experimentally, in an interventional human clinical study, and theoretically, by numerical analysis of upper airway ion and water transport. In a double-blinded, placebo-controlled clinical study, phonation threshold pressure (PTP) was measured prenasal and postnasal inhalation of hypertonic aerosols of NaCl, KCl, CaCl, and MgCl in seven human subjects. Numerical analysis of water and solute exchanges in the upper airways following deposition of these same aerosols was performed using a mathematical model previously described in the literature. PTP decreased by 9%-22% relative to baseline ( < 0.05) for all salts within the first 30 minutes postadministration, indicating effective laryngeal hydration. Only MgCl reduced PTP beyond 90 minutes (21% below baseline at 2 hours postadministration). By numerical analysis, we determined that, while airway water volume up to 15 minutes postdeposition is dictated by osmolarity, after 30 minutes, divalent cation salts, such as MgCl, better retain airway surface liquid (ASL) volume by slow paracellular clearance of the divalent cation. Fall of CFTR chloride flux with rise in ASL height, a promoter of airway acidification, appears to be a signature of permeating cation (NaCl) and nonpermeating anion (mannitol) aerosol deposition. For hypertonic aerosols that lack permeating cation and include permeating anion (CaCl and MgCl), this acid-trigger signature does not exist. Nonpermeating cation and permeating anion hypertonic aerosols appear to hydrate upper airways longer and, rather than provoke, may reduce laryngeal dysfunction such as cough and bronchoconstriction.
Topics: Humans; Administration, Inhalation; Aerosols; Anions; Calcium Chloride; Cations, Divalent; Hydrogen-Ion Concentration; Respiratory Aerosols and Droplets; Saline Solution, Hypertonic; Salts; Sodium Chloride; Water
PubMed: 38354286
DOI: 10.1089/jamp.2023.0039 -
Chemistry (Weinheim An Der Bergstrasse,... Dec 2023Metals play an important role in the structure and functions of various proteins. The combination of metal ions and peptides have been emerging as an attractive field to...
Metals play an important role in the structure and functions of various proteins. The combination of metal ions and peptides have been emerging as an attractive field to create advanced structures and biomaterials. Here, we are reporting the anion-influenced, silver ion coordinated diverse networks of designed short tripeptide 3 -helices with terminal pyridyl groups. The short peptides adopted classical right-handed, left-handed and 3 -helical conformations in the presence of different silver salts. The peptides have displayed conformational flexibility to accommodate different sizes and interactions of anions to yield a variety of metal-coordinated networks. The complexes of metal ions and peptides have shown different porous networks, right- and left-handed helical polymers, transformation of helix into superhelix and 2 : 2 metal-peptide macrocycles. Further, the metal-peptide crystals with inherent dipoles of helical peptides gave striking second harmonic generation response. The optical energy upconversion from NIR to red and green light is demonstrated. Overall, we have shown the utilization of short 3 -helices for the construction of diverse metal-coordinated helical networks and notable non-linear optical effects.
Topics: Silver; Peptides; Molecular Conformation; Anions
PubMed: 37867145
DOI: 10.1002/chem.202303135 -
Journal of the American Society For... Aug 2023Mass spectrometry (MS)-based analysis of RNA oligonucleotides (oligos) plays an increasingly important role in the development of RNA therapeutics and epitranscriptomics...
Mass spectrometry (MS)-based analysis of RNA oligonucleotides (oligos) plays an increasingly important role in the development of RNA therapeutics and epitranscriptomics research. However, MS fragmentation behaviors of RNA oligomers are understood insufficiently. Herein, we characterized the negative-ion-mode fragmentation behaviors of 26 synthetic RNA oligos containing four to eight nucleotides using collision-induced dissociation (CID) on a high-resolution, accurate-mass instrument. We found that in CID spectra acquired under the normalized collision energy (NCE) of 35%, approximately 70% of the total peak intensity was attributed to sequencing ions (, , , , , , , , ), around 25% of the peak intensity came from precursor ions that experienced complete or partial loss of a nucleobase in the form of either a neutral or an anion, and the remainder were internal ions and anionic nucleobases. The top five sequencing ions were the , , , , and ions. Furthermore, we observed that CID fragmentation behaviors of RNA oligos were significantly impacted by their precursor charge. Specifically, when the precursors had a charge from 1 to 5, the fractional intensity of sequencing ions decreased, while that of precursors that underwent either neutral or charged losses of a nucleobase increased. Additionally, we found that RNA oligos containing 3'-U tended to produce precursors with HNCO and/or NCO losses, which presumably corresponded to isocyanic acid and cyanate anion, respectively. These findings provide valuable insights for better comprehending the mechanism behind RNA fragmentation by MS/MS, thereby facilitating the future automated identification of RNA oligos based on their CID spectra in a more efficient manner.
Topics: Oligonucleotides; Tandem Mass Spectrometry; RNA; Ions; Anions; Spectrometry, Mass, Electrospray Ionization
PubMed: 37463304
DOI: 10.1021/jasms.3c00073 -
Effects of charge on protein ion structure: Lessons from cation-to-anion, proton-transfer reactions.Mass Spectrometry Reviews 2024Collision cross-section values, which can be determined using ion mobility experiments, are sensitive to the structures of protein ions and useful for applications to... (Review)
Review
Collision cross-section values, which can be determined using ion mobility experiments, are sensitive to the structures of protein ions and useful for applications to structural biology and biophysics. Protein ions with different charge states can exhibit very different collision cross-section values, but a comprehensive understanding of this relationship remains elusive. Here, we review cation-to-anion, proton-transfer reactions (CAPTR), a method for generating a series of charge-reduced protein cations by reacting quadrupole-selected cations with even-electron monoanions. The resulting CAPTR products are analyzed using a combination of ion mobility, mass spectrometry, and collisional activation. We compare CAPTR to other charge-manipulation strategies and review the results of various CAPTR-based experiments, exploring their contribution to a deeper understanding of the relationship between protein ion structure and charge state.
Topics: Protons; Ions; Proteins; Anions; Cations; Mass Spectrometry
PubMed: 37129026
DOI: 10.1002/mas.21847 -
Water Research Sep 2023Electroneutral carbonyls (ENCs) with low molecular weights (e.g., aldehydes and ketones) are recalcitrant to single water treatment process to achieve ultralow...
Electroneutral carbonyls (ENCs) with low molecular weights (e.g., aldehydes and ketones) are recalcitrant to single water treatment process to achieve ultralow concentration. Residual ENCs are present in reverse osmosis permeate and pose risks to human health during potable use or industrial application in manufacturing processes. Herein, a combined vacuum-UV (VUV) oxidation and anion-exchange resin (AER) adsorption method was developed to treat the ENCs and reduce total organic carbon (TOC) to an ultralow concentration (< 5 μg/L) with high efficiency and at low cost. VUV-AER was 2.1-2.4 times more efficient than VUV alone for the removal of TOC. VUV oxidized the ENCs to electronegative carboxylic acids, which were adsorbed by the AER through electrostatic interactions and hydrogen bonding. When the VUV fluence was lower than 643 mJ cm, the AER could not achieve ultralow TOC removal of ENCs. The treat capacity of 1500-2900 valid bed volume (BVs) was achieved after increasing the VUV fluence to 1929 mJ cm. The AER could more efficiently adsorb carboxylic acids that contained more carboxylic groups or shorter carbon chain. Acetate was identified as the primary breakthrough product at relatively low VUV fluence, and oxalate was the main byproduct at relatively high VUV fluence. A mathematical model to predict TOC breakthrough was developed considering the VUV-oxidation kinetics and the AER breakthrough curve. The model was used to optimize the method to maximize TOC removal and minimize energy consumption. These results imply that VUV-AER is technically feasible and economically applicable to eliminate recalcitrant ENCs to ultralow concentration for the production of water requires high quality (e.g., potable water or electronic-grade ultrapure water).
Topics: Humans; Vacuum; Adsorption; Ultraviolet Rays; Oxidation-Reduction; Water Purification; Carboxylic Acids; Carbon; Anions; Water Pollutants, Chemical
PubMed: 37536248
DOI: 10.1016/j.watres.2023.120435