ABSTRACT
Thioether compounds, prevalent in pharmaceuticals, are of growing environmental concern due to their prevalence and potential toxicity. Peroxy chemicals, including peroxymonosulfate (PMS) and peroxyacetic acid (PAA), hold promise for selectively attacking specific thioether moieties. Still, it has been unclear how chemical structures affect the interactions between thioethers and peroxy chemicals. This study addresses this knowledge gap by quantitatively assessing the relationship between the structure of thioethers and intrinsic reaction rates. First, the results highlighted the adverse impact of electron-withdrawing groups on reactivity. Theoretical calculations were employed to locate reactive sites and investigate structural characteristics, indicating a close relationship between thioether charge and reaction rate. Additionally, we established a SMILES-based model for rapidly predicting PMS reactivity with thioether compounds. With this model, we identified 147 thioether chemicals within the high production volume (HPV) and Food and Drug Administration (FDA) approved drug lists that PMS could effectively eliminate with the toxicity (-lg LC50) decreasing. These findings underscore the environmental significance of thioether compounds and the potential for their selective removal by peroxides.
Subject(s)
Peracetic Acid , Peroxides , Sulfides , Sulfides/chemistry , Peroxides/chemistry , Peracetic Acid/chemistry , Water Pollutants, Chemical/chemistryABSTRACT
Determining conditional stability constant (Kcond) is paramount in assessing complex stability, particularly in Fe(III) complexes that are prevalent in actual surface water and wastewater matrices. In this study, existing methods of Kcond determination were evaluated and a novel UV-Vis spectroscopy method was proposed based on the evaluation of these approaches. Model ligands (ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), and oxalic acid (OA)), as well as common antibiotics (kanamycin (Kana) and tetracycline (TTC)), were employed to determine the Kcond of the Fe(III)-ligand complexes under neutral conditions (pH 6.5). The obtained fitting results revealed that the logKcond were in the order of Fe(III)-EDTA (7.08) > Fe(III)-NTA (4.67) > Fe(III)-OA (4.32) > Fe(III)-TTC (4.28) > Fe(III)-Kana (3.07). In addition to these single ligands, the methodology was extended to the Fe(III) complexation with humic acid (HA), a complex mixture of organic components, where the fitting result indicated a logKcond of 5.02 M-1. The method's application domain was analyzed by numerical analysis and combined with experimental results. The findings demonstrate that the proposed methodology possesses satisfactory measurement capability for Kcond ranging from 103 to 107 M-1, suggesting its broad applicability to the majority of complexes. This method can provide valuable insights into the impact of Fe(III) complexes within the water matrix.
Subject(s)
Anti-Bacterial Agents , Ferric Compounds , Anti-Bacterial Agents/chemistry , Ferric Compounds/chemistry , Dissolved Organic Matter , Ligands , Tetracycline/chemistry , Spectrum Analysis , Nitrilotriacetic Acid/chemistry , Water/chemistry , Edetic Acid , Oxalic AcidABSTRACT
In this study, magnetic material based reduced graphene oxide (M-rGO) was prepared through co-precipitation and displayed high catalytic efficiency together with persulfate (PS) for simultaneous p-arsanilic acid (p-ASA) decomposition and arsenic removal. Linear sweep voltammetry and chronoamperometric measurements with M-rGO revealed that PS was effectively bound to M-rGO surface and probably formed charge transfer complex, in which M-rGO was pivotal in mediating facile electron transfer. The effects of pH, temperatures, anions, p-ASA concentration, PS, and M-rGO dosages on p-ASA decomposition were studied in the system. Excellent degradation of p-ASA was carried out at a wide range of pH values, which was unattainable by other Fenton-like processes. Under optimal conditions, M-rGO exhibited prominent removal of both p-ASA (98.8 %) and inorganic arsenic (89.8 %). M-rGO had reasonably excellent repeatability and stability, and 77.7 % p-ASA degraded in the third recovered catalyst. The advantages of environmental friendliness, short reaction time, and straightforward synthesis of M-rGO will facilitate the development of heterogeneous Fenton-like catalysts under neutral conditions.
ABSTRACT
Iron nanoparticles encapsulated within boron and nitrogen co-doped carbon nanoshell (B/N-C@Fe) were synthesized through a novel and green pyrolysis process using melamine, boric acid, and ferric nitrate as the precursors. The surface morphology, structure, and composition of the B/N-C@Fe materials were thoroughly investigated. The materials were employed as novel catalysts for the activation of potassium monopersulfate triple salt (PMS) for the degradation of levofloxacin (LFX). Linear sweep voltammograms and quenching experiments were used to identify the mechanisms of PMS activation and LFX oxidation by B/N-C@Fe, where SO4- as well as HO were proved to be the main radicals for the reaction processes. This study also discussed how the fluvic acid and inorganic anions in the aqueous solutions affected the degradation of LFX and use this method to simulate the degradation in the real wastewater. The synthesized materials showed a high efficiency (85.5% of LFX was degraded), outstanding stability, and excellent reusability (77.7% of LFX was degraded in the 5th run) in the Fenton-like reaction of LFX. In view of these advantages, B/N-C@Fe have great potentials as novel strategic materials for environmental catalysis.
Subject(s)
Carbon/chemistry , Environmental Pollutants , Magnetite Nanoparticles/chemistry , Nanoshells/chemistry , Environmental Pollutants/analysis , Environmental Pollutants/chemistry , Hydrogen-Ion Concentration , Levofloxacin/analysis , Levofloxacin/chemistry , Oxidation-ReductionABSTRACT
Chiral pharmaceuticals (CPs), including non-steroid anti-inflammatory drugs (NSAIDs), ß-blockers and some herbicide and pesticides, are widely used in aquaculture, clinical treatment and many other fields. However, people are increasingly concerned about such ubiquitous pollutants, which can frequently be detected in contaminated soil and water. In large part, the significant sources of chiral pharmaceuticals stem from industrial processes, such as the direct discharge of untreated or incompletely treated wastewaters containing chiral pharmaceuticals, incorrect storage and use, animal wastes and biosolids. The main ways for human exposure to chiral pharmaceuticals are the disease treatment process and chiral pharmaceuticals contaminants. According to the results of a series of toxic studies, some diseases, even cancers, may be associated with exposure to certain chiral pharmaceuticals. Therefore, the treatment of chiral pharmaceuticals has become an important issue. The current advanced remediation techniques for chiral pharmaceuticals include the conventional method (sorption and sonolysis), biotransformation (an aerobic granular sludge-sequencing batch reactor and constructed wetland system) and advanced oxidation processes (ozonation and photocatalysis). Herein, in this review, we summarize the current status and sources of chiral pharmaceuticals, potential effects on human health, as well as the superiority, disadvantages and prospects of current advanced remediation technologies. Moreover, we also anticipate the prospect of the future research needed for chiral pharmaceuticals pollutant remediation.
Subject(s)
Environmental Pollutants/analysis , Environmental Restoration and Remediation , Pharmaceutical Preparations/chemistry , Animals , Drug-Related Side Effects and Adverse Reactions , Environmental Pollutants/chemistry , Environmental Pollutants/toxicity , Forecasting , Humans , Molecular Structure , Pesticides/chemistry , Pesticides/toxicity , Sewage , Wastewater , Water Pollutants, Chemical/chemistry , WetlandsABSTRACT
An intensive investigation of structure-property relationships in the aggregation-induced enhanced emission (AIEE) of luminescent compounds is essential for the rational design of highly emissive solid-state materials. In the AIEE-active compounds N,N'-bis[3-hydroxy-4-(2'-benzothiazolyl)phenyl]isophthalamide and N,N'-bis[3-hydroxy-4-(2'-benzothiazolyl)phenyl]-5-tert-butylisophthalamide, fast photoinduced twisted intramolecular charge transfer (TICT) of the enol excited state is found to be mainly responsible for the weak emission of their dilute solutions. The photoinduced TICT enol excited state is formed with a greatly distorted configuration, due to the large rotation about the C-N single bond. This facilitates nonradiative TICT decay from the normal enol excited state to the highly twisted enol excited state, rather than proton-transfer decay to the keto excited state. In aggregates, photoinduced nonradiative deactivation of TICT is strongly prohibited, so that excited-state intramolecular proton transfer (ESIPT) becomes the dominant decay, and hence contributes greatly to the subsequent emission enhancement of the keto form. Molecular design and investigation of analogous single-armed compounds further verifies this kind of AIEE mechanism.
ABSTRACT
We developed a new method for glutathione reductase (GR) enzyme sensing via a metal-controlled spontaneous oxidation reaction. A new complex HgL, composed of 3-benzothiazoliny-7-N,N-diethylaminocoumarin (L) and HgCl2, was used as an example for illustration. It was found that ligand L was released from complex HgL by a ligand exchange process in the presence of GSH, which was enzymatic reduced from GSSG in the presence of NADH. Subsequently, free ligand L was spontaneously oxidated to a laser dye (coumarin-6) with both fluorescence enhancement and color change. A good linear relationship between fluorescent intensity and GSH concentrations (in the range of 10-40 µM) elicits the potential use of HgL in GSH detection. Based on this result, complex HgL was applied to identify GR from other proteins/enzymes with good selectivity and sensitivity. HgL can also determine GR in the concentration range from 0.5 to 10 U/mL with a linear relationship. Furthermore, this novel sensing method was also expected to be a useful example for the design of other biosensing systems.
Subject(s)
Biosensing Techniques/instrumentation , Colorimetry/instrumentation , Glutathione Reductase/chemistry , Spectrometry, Fluorescence/instrumentation , Sulfhydryl Compounds/analysis , Enzymes, Immobilized/chemistry , Equipment Design , Equipment Failure Analysis , Oxidation-Reduction , Sulfhydryl Compounds/chemistryABSTRACT
Thiorhodamine-based chemodosimeter A, a disulfide linked dimer, was designed for Hg2+ recognition by virtue of the strong affinity of mercury for sulfur. Spectroscopic results reveal that chemodosimeter A exhibits real-time responses, and high sensitivity and selectivity for Hg2+ in comparison to other cations. These properties are mechanistically ascribed to the transfer from rhodamine spirolactam to the thiazoline-derived open-ring rhodamine via Hg2+ induced desulfurization. The in vitro recognition of Hg2+ in living cells pretreated with A was examined, showing that the concentration of Hg2+ that could be imaged reaches the safety limit for human beings.
Subject(s)
Cells/chemistry , Mercury/analysis , Rhodamines/chemistry , Cells, Cultured , Dimerization , Disulfides/chemistry , Hazardous Substances/analysis , Humans , Mercury/chemistry , Sulfhydryl Compounds/chemistryABSTRACT
A coumarin-based colorimetric chemosensor 1 was designed and synthesized. It exhibits good sensitivity and selectivity for the copper cation over other cations such as Zn(2+), Cd(2+), Pb(2+), Co(2+), Fe(2+), Ni(2+), Ag(+), and alkali and alkaline earth metal cations both in aqueous solution and on paper-made test kits. The change in color is very easily observed by the naked eye in the presence of Cu(2+) cation, whereas other metal cations do not induce such a change. The quantitative detection of Cu(2+) was preliminarily examined.
Subject(s)
Colorimetry/methods , Copper/analysis , Copper/chemistry , Cations, Divalent/chemistry , Magnetic Resonance Spectroscopy , Molecular Structure , TitrimetryABSTRACT
Compound 1, a new fluorescent chemosensor signaling via significantly enhanced fluorescence when bound with cation analytes, was synthesized and characterized. This fluorescent chemosensor exhibits its selectivity to Cd2+ among a series of cations in HEPES buffer solution. Its in vitro sensitivity to Cd2+ was demonstrated in the HK-2 cell line with use of confocal microscopy. The mechanistic selectivity and sensitivity of compound 1 to Cd2+ was discussed on the basis of fluorescence, 1H NMR, and mass spectroscopic results.
Subject(s)
Cadmium/chemistry , Fluorescent Dyes/chemistry , Water/chemistry , Cadmium/pharmacology , Cations/chemistry , Cell Line , Cell Survival/drug effects , Humans , Magnetic Resonance Spectroscopy , Molecular Structure , Solubility , SpectrophotometryABSTRACT
A new complex Cu(II)/L, composed of 2,9-bis(4'-hydroxyphenyl)phenanthroline (L) and Cu(II), was synthesized as an efficient chloride-detection fluorescent chemosensor with high selectivity and sensitivity over other halide anions, F(-), Br(-), I(-). The recognition mechanism was discussed primarily.
Subject(s)
Chlorides/analysis , Fluorescent Dyes/chemistry , Organometallic Compounds/chemistry , Phenanthrolines/chemistry , Spectrometry, Fluorescence , Fluorescent Dyes/chemical synthesis , Organometallic Compounds/chemical synthesis , Phenanthrolines/chemical synthesis , Sensitivity and SpecificityABSTRACT
[reaction: see text] A new sensing mechanism based on C=N isomerization, which shows a very significant fluorescence enhancement to the metal cations in a simple and efficient way, is demonstrated. A coumarin derivative (L) containing a C=N group was designed as an example for illustration. The free ligand L is almost nonfluorescent due to the isomerization of C=N double bond in the excited state. However, the solution of ligand shows about a 200-fold increase of fluorescence quantum yield (about 30%) upon addition of Zn(ClO4)2.
ABSTRACT
A novel fluorescent chemosensor based on aminonaphthol, which can selectively recognize copper(II) over other metal ions in aqueous solution within a broad pH span, was synthesized.
Subject(s)
Copper/analysis , Naphthalenes/chemistry , Organometallic Compounds/chemistry , Spectrometry, Fluorescence/methods , Water/analysis , Fluorescence , Hydrogen-Ion Concentration , Naphthalenes/chemical synthesis , Organometallic Compounds/chemical synthesis , Solutions/analysisABSTRACT
[reaction: see text]. A novel fluorescent chemosensor (compound 1) containing aminonaphthol, which selectively recognizes fluoride anion with high sensitivity, was synthesized. The fluorescence of compound 1 was quenched rapidly by fluoride ion, and a new peak at a longer wavelength emerged concurrently, which constituted the signature for fluoride detection. The mechanism of exciplex formation was proposed for the interesting observation.
ABSTRACT
The fluorescent compound N-substituted 2,6-bis(benzimidazol-2-yl)pyidine (1) has been synthesized. The fluorescent characteristics of the compound 1 and 2,6-bis(benzimidazol-2-yl)pyidine (2) and the complexes formed between the two compounds and different metal ions have also been investigated. The results show that the compound 1 possesses a specific ability to form complex with Cu(2+) ion, but the compound 2 have not such a property. It is proposed that the specific recognition ability of compound 1 to Cu(2+) may be attributed to the cyclic configuration of this compound in polar solvent.
Subject(s)
Copper/analysis , Copper/chemistry , Cations, Divalent/chemistry , Dimethylformamide/analysis , Dimethylformamide/chemistry , Fluorescence , Fluorescent Dyes/analysis , Fluorescent Dyes/chemistry , Models, Molecular , Molecular Conformation , Molecular Structure , Spectrometry, FluorescenceABSTRACT
We demonstrate bulk synthesis of highly crystalline Cd-doped ZnO nanocantilever arrays (CZNAs) using Cd and Zn powders at 600 degrees C, which is characterized via scanning electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy, selected area electron diffraction, and high resolution TEM. The results show that the as-prepared CZNAs have diameters of about 15-50 nm, and lengths up to 400 nm and the corresponding process of growth is suggested for conventional vapor solid mechanism.
Subject(s)
Coumarins/chemistry , Pressure , Crystallization , Crystallography, X-Ray , Fluorescence , Phase Transition , Spectrum Analysis , Time FactorsABSTRACT
The metal-ligand complex 1 ([Mg (L)] (2+)) (or 2 ([Ca (L)]( 2+))) was demonstrated to selectively bind HSO(4)(-) (or H(2)PO(4)(-)) over other anions by using UV-vis absorption and fluorescence spectroscopy. The studied complex exhibits the remarkable color change and fluorescence quenching upon introducing HSO(4)(-) (or H(2)PO(4)(-)) anion in acetonitrile. Both the mechanism and structure of the secondary complex of complex 1 with anion were proposed on the basis of theoretical computation.