Reactivity of unactivated peroxymonosulfate and peroxyacetic acid with thioether micropollutants: Mechanisms and rate prediction.

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.

Estimation of stability constants of Fe(III) with antibiotics and dissolved organic matter using a novel UV-vis spectroscopy method.

Determining conditional stability constant (K) 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 K 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 K of the Fe(III)-ligand complexes under neutral conditions (pH 6.

Simultaneous degradation of p-arsanilic acid and inorganic arsenic removal using M-rGO/PS Fenton-like system under neutral conditions.

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.

Insights into the oxidation of organic contaminants by iron nanoparticles encapsulated within boron and nitrogen co-doped carbon nanoshell: Catalyzed Fenton-like reaction at natural pH.

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).

Chiral pharmaceuticals: Environment sources, potential human health impacts, remediation technologies and future perspective.

Chiral pharmaceuticals (CPs), including non-steroid anti-inflammatory drugs (NSAIDs), β-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.

Restriction of photoinduced twisted intramolecular charge transfer.

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.

Enzyme sensing based on a controllable oxidation reaction.

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.

Dithiolane linked thiorhodamine dimer for Hg2+ recognition in living cells.

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.

Colorimetric test kit for Cu2+ detection.

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.

A water-soluble "switching on" fluorescent chemosensor of selectivity to Cd2+.

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.

Fluorescence turn on of coumarin derivatives by metal cations: a new signaling mechanism based on C=N isomerization.

[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.

An efficient chloride-selective fluorescent chemosensor based on 2,9-bis(4'-hydroxyphenyl)phenanthroline Cu(II) complex.

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.

Novel fluorescent sensor for detection of Cu(II) in aqueous solution.

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.

New fluorescent chemosensor based on exciplex signaling mechanism.

[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.

Large-scale fabrication and characterization of Cd-doped ZnO nanocantilever arrays.

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.

An effective fluorescent chemosensor for the detection of copper(II).

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.

A novel colorimetric and fluorescent anion chemosensor based on the flavone quasi-crown ether-metal complex.

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.