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1.
Ecotoxicol Environ Saf ; 214: 112115, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33691242

RESUMEN

Nanoplastics (NPs) are becoming an emerging pollutant of global concern. A potential risk of NPs is that they can serve as carriers and synergistically function with other contaminants to cause diseases. A variety of diseases such as Alzheimer's disease are related to the generation of amyloid fibrils, and insulin is typically used as a model to study the fibrillation process. In this study, we examined the fibrillation of insulin promoted by polystyrene nanoplastics (PSNPs) alone and synergistically with organic contaminants (denoted as X, X = pyrene, bisphenol A, 2,2',4,4'-tetrabromodiphenyl ether, 4,4'-dihydroxydiphenylmethane, or 4-nonylphenol) having different polarities using thioflavin T fluorescence assays, dynamic light scattering, and circular dichroism spectroscopy. The presence of PSNPs and small organic contaminants decreased the lag phase time (tlag) for insulin fibrillation from 54.6 h to 35-51 h and their combination (PS-X) enhanced this process (tlag = 21-30 h). Notably, the lag phase time for insulin fibrillation with PS-nonpolar contaminants, PS-weakly polar contaminants, and PS-polar contaminants is around 20.8, 26.7, and 30.1 h, respectively, indicating the synergistic effect of PS-nonpolar contaminants or PS-weakly polar contaminants was more obvious than that of PS-polar contaminants. Moreover, molecular dynamic simulation reveal the interactions between insulin and PSs or small organic contaminants are primarily driven by van der Waals forces and hydrophobic interactions. Overall, the findings of this study underscore the potentially significant environmental impact of small organic contaminants assisting NPs in promoting insulin fibrillation.


Asunto(s)
Contaminantes Ambientales/química , Insulina/química , Microplásticos/química , Nanopartículas/química , Poliestirenos/química , Compuestos de Bencidrilo/química , Éteres Difenilos Halogenados/química , Fenoles/química , Pirenos/química
2.
Food Chem ; 348: 129106, 2021 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-33516999

RESUMEN

Deep eutectic solvents (DESs) are a new class of green "designer solvent"; its physicochemical properties can be easily tuned by adjusting DES' constituents, chemical ratio and water content. In this study, three hydrophobic DESs with low viscosity, low density, and melting points close to room temperature were designed and synthesized. Based on these DESs, an air-assisted liquid-liquid microextraction technique was developed based on the solidification of floating DESs for the simultaneous determination of bisphenols and polycyclic aromatic hydrocarbons (PAHs) via HPLC. The microextraction parameters were optimized via the Plackett-Burman design and response surface methodologies. The method shows satisfactory linearity (R2 ≥ 0.9928), a low limit of detection (0.16-0.75 µg L-1) and satisfactory precision (≤2.3%), and was successfully applied for the simultaneous determination of bisphenols and PAHs from tea infusions with satisfactory recoveries (82.0-116.6%). This method is simple, rapid, economical, environmentally compatible, dispersive solvent-frees and centrifugation-free, and has promising applications in food safety.


Asunto(s)
Aire , Compuestos de Bencidrilo/análisis , Microextracción en Fase Líquida/métodos , Fenoles/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Solventes/química , Té/química , Agua/química , Compuestos de Bencidrilo/química , Compuestos de Bencidrilo/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Análisis de los Alimentos , Contaminación de Alimentos/análisis , Interacciones Hidrofóbicas e Hidrofílicas , Límite de Detección , Fenoles/química , Fenoles/aislamiento & purificación , Fenómenos Físicos , Hidrocarburos Policíclicos Aromáticos/química , Hidrocarburos Policíclicos Aromáticos/aislamiento & purificación , Viscosidad , Contaminantes Químicos del Agua/análisis
3.
J Chromatogr A ; 1638: 461886, 2021 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-33465586

RESUMEN

Major type of internal can coating used for food and beverages is made from epoxy resins, which contain among their components bisphenol A (BPA) or bisphenol A diglycidyl ether (BADGE). These components can be released and contaminate the food or beverage. There is no specific European legislation for coatings, but there is legislation on specific substances setting migration limits. Many investigations have paid attention to BPA due to its classification as endocrine disruptor, however, few studies are available concerning to other bisphenol analogues that have been used in the manufacture of these resins. To evaluate the presence of this family of compounds, ten cans of beverages were taken as study samples. Firstly, the type of coating was verified using an attenuated total reflectance-FTIR spectrometer to check the type of coating presents in most of the samples examined. A screening method was also performed to investigate potential volatiles from polymeric can coatings of beverages using Purge and Trap (P&T) technique coupled to gas chromatography with mass spectrometry detection (GC-MS). Moreover, a selective analytical method based on high performance liquid chromatography with fluorescence detection (HPLC-FLD) for the simultaneous identification and quantification of thirteen compounds including bisphenol analogues (BPA, BPB, BPC, BPE, BPF, BPG) and BADGEs (BADGE, BADGE.H2O, BADGE.2H2O, BADGE.HCl, BADGE.2HCl, BADGE.H2O.HCl, cyclo-di-BADGE) in the polymeric can coatings and in the beverage samples was applied. In addition, a liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method was optimized for confirmation purposes. The method showed an adequate linearity (R2 >0.9994) and low detection levels down to 5 µg/L. Cyclo-di-BADGE was detected in all extracts of polymeric coatings. The concentrations ranged from 0.004 to 0.60 mg/dm2. No detectable amounts of bisphenol related compounds were found in any of the beverage samples at levels that may pose a risk to human health, suggesting a low intake of bisphenols from beverages.


Asunto(s)
Bebidas/análisis , Cromatografía/métodos , Polímeros/química , Compuestos de Bencidrilo/análisis , Compuestos de Bencidrilo/química , Dieta , Compuestos Epoxi/química , Resinas Epoxi/química , Cromatografía de Gases y Espectrometría de Masas , Humanos , Fenoles/análisis , Estándares de Referencia , Reproducibilidad de los Resultados , Espectrofotometría Infrarroja , Espectroscopía Infrarroja por Transformada de Fourier , Volatilización
4.
Food Chem ; 345: 128841, 2021 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-33360062

RESUMEN

In this study, a novel porous composite (Fe3O4@TAPB-COF@ZIF-8) consisting of metal-organic and covalent organic frameworks was developed and applied to the magnetic solid-phase extraction (MSPE) of bisphenols. The extraction parameters such as the extraction time, solution pH, amounts of adsorbent, and ionic strength were investigated to obtain the best extraction conditions. By optimizing the MSPE, a convenient and sensitive analytical method was established in combination with high-performance liquid chromatography. The method achieved low detection limits (0.04-0.05 ng mL-1), wide linear range (0.25-1000 ng mL-1), good repeatability (1.20-4.30%), good reproducibility (1.34-4.03%), and satisfactory recoveries of four functional beverages (66.2-116.6%).


Asunto(s)
Compuestos de Bencidrilo/análisis , Compuestos de Bencidrilo/aislamiento & purificación , Bebidas/análisis , Límite de Detección , Fenómenos Magnéticos , Estructuras Metalorgánicas/química , Fenoles/análisis , Fenoles/aislamiento & purificación , Extracción en Fase Sólida/métodos , Adsorción , Compuestos de Bencidrilo/química , Cromatografía Líquida de Alta Presión , Óxido Ferrosoférrico/química , Concentración Osmolar , Fenoles/química , Porosidad , Reproducibilidad de los Resultados
5.
Food Chem ; 338: 127656, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-32798821

RESUMEN

Bisguaiacols are promising lignin-derivable alternatives to bisphenol A (BPA), but limited bioassay data are available on their estrogenic activity (EA). Herein, we investigated the estrogen receptor alpha (ERα)-mediated EA of six newly synthesized bisguaiacols, which differed in the number and location of methoxy substituents, through in vitro assays: MCF-7 cell proliferation and VM7Luc4E2 transactivation. The six bisguaiacols had undetectable EA at concentrations less than 10-7 M, most importantly, with significantly lower EA than BPA over an environmentally relevant range of 10-10-10-7 M. Adding a single methoxy group led to significant reduction in EA in all cases, relative to BPA and one petroleum-derived BPA analogue (bisphenol F, BPF), and the incorporation of more methoxy groups had subtler, but pronounced, impacts on either ERα binding or MCF-7 cell proliferation. In short, the six lignin-inspired bisguaiacols presented herein are viewed as promising sustainable alternatives to BPA and BPF.


Asunto(s)
Compuestos de Bencidrilo/química , Estrógenos/química , Lignina/química , Fenoles/química , Compuestos de Bencidrilo/farmacología , Proliferación Celular/efectos de los fármacos , Estrógenos/metabolismo , Estrógenos/farmacología , Humanos , Células MCF-7 , Oxidación-Reducción , Fenoles/farmacología , Unión Proteica , Relación Estructura-Actividad , Activación Transcripcional/efectos de los fármacos
6.
J Oleo Sci ; 69(11): 1389-1401, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33132278

RESUMEN

The oral route is the most prevalent route of drug administration among various routes. Dapagliflozin is an oral hypoglycemic drug used for lowering the blood glucose level. The objective of this work is to developed and optimized dapagliflozin loaded nanostructured lipid carriers (DG-NLCs) for the improvement of oral delivery. DG-NLCs were prepared by a high-pressure homogenization method (hot) and optimized by Box-Behnken design software using lipid, surfactant, and homogenization cycle as an independent variable. DG-NLCs were evaluated for particle size (Y1), entrapment efficiency (Y2), drug release (Y3). The DG-NLCs were further evaluated for morphology, thermal and X-ray diffraction analysis, ex-vivo intestinal permeation, and stability study. Particle size (nm), entrapment efficiency (%) and drug release (%) of all seventeen formulations were found in the range of 113.71-356.22 nm, 60.43-96.54% and 63.44-83.62% respectively. Morphology of optimized formulation exhibited spherical in shape confirmed by transmission electron microscopy. Thermal and X-ray diffraction analysis of NLCs showed the drug was solubilized and lost the crystallinity. DG-NLCs-opt exhibited dual release pattern initial fast and later sustained-release (90.01±2.01% in 24 h) whereas DG-dispersion showed 31.54±1.87% release in 24 h. Korsmeyer-Peppas model was found to be the best fit model (R2=0.999). The DG-NLCs-opt exhibited significant-high (p < 0.05, 1.293 µg/cm2/h) flux than DG-dispersion (0.2683 µg/cm2/h). Apparent permeation coefficient of DG-NLCs-opt was found to be significantly higher (p < 0.05, 4.14×10-5 cm/min) than DG-dispersion (8.61×10-6 cm/min). The formulation showed no significant changes (p < 0.05) on six months of storage study at 25±2°C/60±5%RH. The finding concluded that quality by design (QbD) based lipid nanocarrier for oral delivery could be a promising approach of dapagliflozin for the management of diabetes.


Asunto(s)
Compuestos de Bencidrilo , Portadores de Fármacos , Composición de Medicamentos , Sistemas de Liberación de Medicamentos/métodos , Liberación de Fármacos , Glucósidos , Hipoglucemiantes , Absorción Intestinal , Lípidos , Nanopartículas , Nanoestructuras , Administración Oral , Compuestos de Bencidrilo/química , Compuestos de Bencidrilo/metabolismo , Formas de Dosificación , Portadores de Fármacos/química , Diseño de Fármacos , Estabilidad de Medicamentos , Glucósidos/química , Glucósidos/metabolismo , Hipoglucemiantes/química , Hipoglucemiantes/metabolismo , Modelos Biológicos , Tamaño de la Partícula
7.
Ecotoxicol Environ Saf ; 204: 111093, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32805502

RESUMEN

Phenolic Endocrine Disrupting Chemicals (EDCs) have drawn more and more interest due to their prevalence and persistence in aquatic environment. To study the adsorption of various phenolic EDCs on river sediments under natural conditions, we first sought to analyze the distribution characteristics of phenol and bisphenol A (BPA) in sediment from the Bahe River. The static adsorption experiments contained either single- or dual-contaminant of phenol and/or BPA in the system; they were conducted to characterize the adsorption of these two pollutants in the surface sediments and the main factors affecting the adsorption processes of the dual-contaminant system, including particle size, humic acid (HA) concentration, pH, and temperature. Results showed that in certain seasons, there was a significant correlation between the levels of phenol and BPA in Bahe sediments. When comparing the adsorption behaviors of phenol and BPA on sediments in single- and dual-contaminant systems, we found that the phenol adsorption behavior varied, while that of BPA remained consistent across the different systems. Moreover, different effects were observed with regards to a single factor and the interaction of multiple factors on the adsorption of pollutants. Of the four single factors, only HA concentration had a significant effect on the phenol adsorption in sediment. When considering the interaction of multiple factors, the interaction between HA concentration and temperature significantly promoted the adsorption of phenol. The influence of factors on the adsorption of BPA was in the following order: particle size > HA concentration > pH > temperature. Particle size significantly inhibited BPA adsorption in the sediment, while the interaction between particle size and pH increased BPA adsorption.


Asunto(s)
Compuestos de Bencidrilo/química , Fenol/química , Fenoles/química , Contaminantes Químicos del Agua/química , Adsorción , Disruptores Endocrinos/análisis , Contaminantes Ambientales , Sedimentos Geológicos/química , Concentración de Iones de Hidrógeno , Tamaño de la Partícula , Fenoles/análisis , Ríos/química , Temperatura , Contaminantes Químicos del Agua/análisis
8.
Free Radic Res ; 54(7): 535-539, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32838569

RESUMEN

The relationship between radical-scavenging rate constants (k) in an aprotic medium and thermodynamic parameters calculated by density functional theory (DFT) was investigated for 7 flavonols, which are myricetin (Myr), quercetin (Que), morin (Mor), kaempferol (Kae), 2'-methylquercetin (2'-MeQue), 5'-methylquercetin (5'-MeQue), and 2',5'-dimethylquercetin (Me2Que). The k values were determined for the reaction between the flavonols and galvinoxyl radical used as a reactivity model of reactive oxygen species in deaerated acetonitrile at 298 K. The energy difference values (D HT, HT: hydrogen transfer) between the flavonols and the corresponding radicals, which equal to the relative O-H bond dissociation energies of the OH groups in the flavonols and ionisation potentials (IP) were calculated by DFT at the B3LYP/6-31++G(d) level with C-PCM solvation model parameterised for acetonitrile. Among the 7 flavonols used in this study, calculated IP values of 4 flavonols exhibited a linear correlation with log k, suggesting that the radical-scavenging reaction of these flavonols may proceed via an electron transfer as the rate determining step.


Asunto(s)
Flavonoles/química , Depuradores de Radicales Libres/química , Antioxidantes/química , Compuestos de Bencidrilo/química , Teoría Funcional de la Densidad , Cinética , Especies Reactivas de Oxígeno/química , Relación Estructura-Actividad , Termodinámica
9.
Chemosphere ; 261: 127715, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32717514

RESUMEN

Advanced oxidation processes (AOPs) based on the activation of hydrogen peroxide (H2O2) and persulfate (PS) by minerals have received increasing interest for environmental remediation. Herein, H2O2 and PS activation systems employing goethite as a catalyst were discovered for the rapid degradation of BPA with the generation of reactive oxidation species (ROS) and for the reduction of total organic carbon (TOC) in aqueous solutions. The morphology of goethite were characterized by XRD, SEM, BET, TEM, etc. As a result, the oxidant efficiency of the goethite/H2O2 system (75.9%) was higher than that of the goethite/PS system (61.4%) after 240 min due to the restricted radical scavenging. According to the results of electron paramagnetic resonance (EPR) and radical quenching experiments, the main active ROS during the BPA degradation process were OH and SO4-. The two reaction systems were all pH-dependent that BPA can be effectively degraded in the goethite/PS system under acidic, neutral and weakly alkaline conditions, while the most inefficient degradation under alkaline conditions in the goethite/H2O2 system. Moreover, goethite showed good structural stability in the two systems. Several reaction products were detected using LC-MS, and the mechanisms for three systems were proposed. Density functional theory (DFT) was employed to study the conceivable degradation pathways of BPA in the two processes. This work reveals novel mechanistic insights regarding H2O2 and PS activation over goethite and implies the great potential application of the PS/mineral process in water and wastewater treatment.


Asunto(s)
Compuestos de Bencidrilo/química , Fenoles/química , Contaminantes Químicos del Agua/química , Restauración y Remediación Ambiental , Peróxido de Hidrógeno/química , Compuestos de Hierro , Minerales , Oxidantes , Oxidación-Reducción , Sulfatos/química , Aguas Residuales , Contaminantes Químicos del Agua/análisis
10.
Food Chem ; 331: 127326, 2020 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-32674069

RESUMEN

A precise and accurate GC-MS/MS method with ng L-1 LLOQs, acceptable recovery (78-107%) and estimated uncertainty (U > 20%, except at LLOQ) was developed following the Eurachem guidelines. We established the migration and stability of twelve bisphenols in two food simulants (C: 20% ethanol, and B: 3% acetic acid) from beverage cans (n = 16) and reusable metal and plastic sports bottles (n = 51). Bisphenols were stable in dried (eight weeks, -20 °C) and derivatised extracts (seven days, 21 °C). Cans leached BPA (<5865 ng L-1), three BPF isomers (8.2-1286 ng L-1) and BPAP (1.6 ng L-1), while bottles leached BPA (<222 ng L-1) and BPF, BPE, BPB and BPZ (1.1-4.6 ng L-1). Simulant C was more aggressive than simulant B, and concentrations of bisphenols decreased with consecutive exposure to simulants. Levels of BPA migrating from cans did not exceed the specific migration limits.


Asunto(s)
Compuestos de Bencidrilo/química , Bebidas/análisis , Equipo Reutilizado , Embalaje de Alimentos , Fenoles/química , Deportes , Contaminación de Alimentos/análisis
11.
Food Chem ; 331: 127311, 2020 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-32569967

RESUMEN

A magnetic hydrophilic molecularly imprinted material (MIM) with multiple stimuli-responses was prepared for efficient recognition of bisphenol A (BPA). MIM consisted of a magnetic core, an inner silica dioxide shell and an outer hydrophilic polymer shell, responsive for rapid magnetic separation, protection of the magnetic core and pH-/thermo-sensitivity to BPA, respectively. Controlled adsorption and release of BPA by pH/temperature regulation were realized through the reversible components of poly[N-isopropylacrylamide-co-2-(dimethylamino)ethyl methacrylate (NIPAM-DMAEMA)] (PND). The resultant MIM possessed superior affinity, selectivity and kinetics to BPA in aqueous solution. MIM was successfully applied to detect BPA in beverages via dispersive solid-phase extraction (d-SPE) coupled with high performance liquid chromatography (HPLC), exhibiting satisfactory recoveries of 80.70-108.18% with relative standard deviations (RSD) below 6.08%. The limit of detection of BPA was obtained as low as 3.75 nmol/L. The versatile MIM could be a promising alternative for extraction/removal of BPA in complicated samples by multiple-stimuli regulations.


Asunto(s)
Compuestos de Bencidrilo/química , Bebidas/análisis , Imanes/química , Impresión Molecular , Fenoles/química , Polímeros/química , Polímeros/síntesis química , Adsorción , Compuestos de Bencidrilo/análisis , Compuestos de Bencidrilo/aislamiento & purificación , Interacciones Hidrofóbicas e Hidrofílicas , Metacrilatos/química , Fenoles/análisis , Fenoles/aislamiento & purificación , Dióxido de Silicio/química , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación
12.
Chemosphere ; 259: 127431, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32593823

RESUMEN

Designing heterostructure of photocatalyst as an efficient approach to boost visible light-driven photocatalytic degradation, we prepared a series of cobalt-based ZIF coordinated with defective TiO2-x, denoted as B-TiO2-x@ZIF-67 composites, through wrapping defective B-TiO2-x on ZIF-67 for promoting photocatalytic degradation efficiency of biphenyl A. The B-TiO2-x@ZIF-67 composites displayed superior photocatalytic performance to pure TiO2-x or ZIF-67 because of faster separation of photogenerated charge carriers and more suitable redox potentials. Such a novel photo-Fenton-like system composed of B-TiO2-x@ZIF-67/H2O2/visible light accelerated the peroxidative degradation of biphenyl An up to a removal efficiency of 95.30%, which is also higher than that of photocatalysis or Fenton-like reaction alone. In addition, the degradation efficiency of biphenyl A is unchanged after catalyst reuse of four cycles. Integrating the trapping experiments and electrochemical analysis, we found the oxygen vacancy on B-TiO2-x capturing the electrons to promote the separation of photogenerated charges, meanwhile the Co(II) in the composite decomposed hydrogen peroxide (H2O2) to produce more •OH radical. Both of them mutually boosted the removal efficiency. Finally, feasible degradation pathways of biphenyl A were proposed based on the assay of LC-MS spectrometry. This strategy offers a novel insight into fabrication of Co-ZIF-based TiO2-x materials and application to visible light-driven photocatalytic and Fenton-like degradation reaction.


Asunto(s)
Compuestos de Bencidrilo/química , Cobalto/química , Fenoles/química , Catálisis , Peróxido de Hidrógeno/química , Luz , Procesos Fotoquímicos , Titanio/química
13.
Chemosphere ; 259: 127439, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32593825

RESUMEN

The presence of emerging micropollutants and dyes in water resource has raised global concern about their intense effects to aquatic environments, ecosystem and human health in general. So far, various adsorbents have been suggested for reducing the levels of bisphenol A, methylene blue and neutral red contamination in wastewaters. However, a number of these adsorbents seemed to have low adsorptive capacities and regeneration performances. In view of these, batch experiment was performed to decontaminate these pollutants from aqueous solutions using an optimized bagasse-ß-cyclodextrin polymer (SB-ß-CD). Characterization studies of SB-ß-CD were performed using FTIR, pH point of zero charge, XRD and BET methods. Adsorption of BPA, MB and NR was favored at lower temperature (298 K) and pH of 7.0, 9.0 and 6.0, respectively. The maximum adsorption capacity of BPA, MB and NR at 298 K was 121, 963 and 685 mg g-1, respectively. Hydrogen bonding through host-guest inclusion and electrostatic interactions could respectively attribute to uptake of BPA and MB/NR onto SB-ß-CD. Adsorption kinetics of three pollutants followed pseudo-second-order model. Langmuir and Freundlich models were fitted to describe the adsorption of BPA and MB/NR, respectively. Thermodynamic parameters confirmed the occurrence of physical adsorption which is spontaneous and exothermic in nature. SB-ß-CD loaded with BPA and MB/NR was certainly reused by 75% ethanol and 0.1 mol L-1 HCl solutions, respectively. Novel SB-ß-CD showed better adsorptive capacity and regeneration performances; consequently can offers practical application for removal of BPA, MB and NR from wastewaters.


Asunto(s)
Compuestos de Bencidrilo/química , Celulosa/química , Ciclodextrinas/química , Azul de Metileno/química , Rojo Neutro/química , Fenoles/química , Adsorción , Ecosistema , Polímeros , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , beta-Ciclodextrinas
14.
Chemosphere ; 256: 127104, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32470734

RESUMEN

Iron(III)-tetraamidomacrocyclic ligand (FeIII-TAML) activators have drawn great attentions due to the high reactivity to degrade organic pollutants. However, previous studies showed that the reactivity and stability of FeIII-TAML were both strongly pH-dependent, which dramatically decrease at lower pH levels. Herein, FeIII-TAML/DODMA (dimethyldioctadecylammonium chloride) microspheres with diameters ranging from 100 to 2000 nm were synthesized via a surfactant-assisted self-assembly technique. The newly synthesized FeIII-TAML/DODMA composite exhibits superior reactivity compared to free FeIII-TAML as indicated by the degradation of bisphenols (i.e., bisphenol A and its analogues) over a wide pH range (i.e., pH 4.5-10.0). Based on the adsorption results and quantitative structure-activity relationship (QSAR) models, the enhanced reactivity of FeIII-TAML/DODMA is mainly ascribed to the hydrophobic sorption of bisphenols. Moreover, the enhanced ionization of the axial water molecule associated with FeIII-TAML could further enhance the reactivity of synthesized microcomposites, which was confirmed by the results of infrared and Raman spectra. Furthermore, FeIII-TAML/DODMA shows distinct acid-resistance as explained by the protection of the hydrophobic alkyl chains of DODMA. This novel method would provide a simple and effective strategy to expand the application of FeIII-TAML in a wide pH range and render FeIII-TAML/DODMA microstructure as a potential catalyst for treatment of bisphenol compounds.


Asunto(s)
Compuestos de Bencidrilo/química , Modelos Químicos , Fenoles/química , Catálisis , Compuestos Férricos/química , Peróxido de Hidrógeno/química , Hierro/química , Ligandos , Oxidación-Reducción
15.
Mikrochim Acta ; 187(5): 262, 2020 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-32270383

RESUMEN

A hybrid conjugate of reduced graphene oxide/ferrous-ferric oxide nanoparticles (rGO-Fe3O4 NPs) is characterized and assembled with chitosan and laccase to form a layered functional superstructure. After its characterization by field-effect scanning electron microscopy, energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, attenuated total reflectance Fourier transform infrared, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), the nanocomposite has been deposited on glassy carbon for the enzyme-mediated electrochemical determination of the endocrine disruptor bisphenol A (BPA). Proof-of-concept assays conducted by using CV, EIS, and square wave voltammetry reveal that the enzymatic biosensor provides linear response in a wide range of BPA concentrations (6-228 ppb), very high sensitivities, and excellent durability (over 1-month storage). Using amperometric detection, remarkable sensitivities (2080 µA µM-1 cm-2) and detection limits (18 nM) are attained. Applications to real samples of bottled water proved feasible with recoveries in the range 107-124%. Graphical abstract Reduced graphene oxide conjugated with magnetite nanoparticles (rGO-Fe3O4) was assembled with laccase (wine-colored dots) and chitosan for the electrochemical determination of bisphenol A. The enzymatic biosensor exhibited excellent linearity (6-228 ppb) and stability. Best sensitivity (2080 µA µM-1 cm-2, detection limit 18 nM) was obtained by amperometry.


Asunto(s)
Compuestos de Bencidrilo/análisis , Técnicas Biosensibles/métodos , Técnicas Electroquímicas/métodos , Grafito/química , Nanopartículas de Magnetita/química , Nanocompuestos/química , Fenoles/análisis , Compuestos de Bencidrilo/química , Quitosano/química , Agua Potable/análisis , Lacasa/química , Límite de Detección , Oxidación-Reducción , Fenoles/química , Prueba de Estudio Conceptual , Reproducibilidad de los Resultados , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/química
16.
Food Chem ; 317: 126459, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32113141

RESUMEN

The widespread exposure of bisphenol A (BPA) presents a significant risk to human health. A rapid, ultra-sensitive and label-free colorimetric aptasensor using high affinity truncated aptamers was developed for BPA detection. Truncated 38-mer and 12-mer aptamers specific for BPA were obtained through rationally truncation from 63-mer BPA aptamer. The dissociation constants (Kd) of 38-mer and 12-mer aptamers were determined to be 13.17 nM and 27.05 nM. Then, truncated aptamers were used in label-free colorimetric detection assays based on gold nanoparticles (AuNPs). The limit of detections of aptasensors using 38-mer and 12-mer aptamers were 7.60 pM and 14.41 pM, which were 265-fold and 140-fold lower than that of the aptasensor using 63-mer aptamer, respectively. The recovery rates in milk, orange juice and mineralized water samples were 93.88% to 107.30%. Therefore, the developed BPA colorimetric aptasensor using truncated aptamers has great application prospects in food safety control and environmental monitoring.


Asunto(s)
Aptámeros de Nucleótidos/química , Compuestos de Bencidrilo/análisis , Colorimetría/métodos , Análisis de los Alimentos/métodos , Fenoles/análisis , Animales , Aptámeros de Nucleótidos/metabolismo , Compuestos de Bencidrilo/química , Compuestos de Bencidrilo/metabolismo , Análisis de los Alimentos/instrumentación , Contaminación de Alimentos/análisis , Jugos de Frutas y Vegetales/análisis , Oro/química , Límite de Detección , Nanopartículas del Metal/química , Leche/química , Simulación del Acoplamiento Molecular , Fenoles/química , Fenoles/metabolismo , Sensibilidad y Especificidad
17.
Environ Res ; 182: 109090, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32069761

RESUMEN

A new photocatalyst of TiO2/C3N4 composite (TiO2/g-C3N4) was synthesized by the hydrothermal method. The characterization showed that TiO2/g-C3N4 extended absorption light range and enhanced generation efficiency of photo-induced electron. Under the simulated solar irradiation, the photodegradation rate of bisphenol A (BPA) by TiO2/g-C3N4 was twice as fast as that of g-C3N4. Furthermore, TiO2/g-C3N4 presented the good stability and excellent selectivity for BPA degradation. The high degradation rate of BPA by TiO2/g-C3N4 was demonstrated to be superoxide radical (·O2-) and singlet oxygen (1O2) by radical quenching experiment, which was further evidenced by EPR, XPS, DRS and PL analysis. These findings revealed that TiO2/g-C3N4 can be used as a potential photocatalyst for removing organic pollutants in actual environmental remediation.


Asunto(s)
Compuestos de Bencidrilo , Luz , Fenoles , Compuestos de Bencidrilo/química , Catálisis , Fenoles/química , Fotólisis , Titanio
18.
Adv Mater ; 32(12): e1907932, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32026524

RESUMEN

Water contamination by organic pollutants is ubiquitous and hence a global concern due to detrimental effects on the environment and human health. Here, it is demonstrated that amyloid fibrils aerogels are ideal adsorbers for removing organic pollutants from water. To this end, amyloid fibrils prepared from ß-lactoglobulin, the major constituent of milk whey protein, are used as building blocks for the fabrication of the aerogels. The adsorption of Bentazone, Bisphenol A, and Ibuprofen, as model pollutants, is evaluated under quasi-static conditions, without use of energy or pressure. Through adsorption by amyloid fibrils aerogel, excellent removal efficiencies of 92%, 78%, and 98% are demonstrated for Bentazone, Bisphenol A, and Ibuprofen, respectively. Furthermore, the maximum adsorption capacity of amyloid fibrils aerogel for Bentazone, Bisphenol A, and Ibuprofen is 54.2, 50.6, and 69.6 mg g-1 , respectively. To shed light on the adsorption equilibrium process, adsorption isotherms, binding constants, saturation limits, and the effect of pH are evaluated. Finally, the regeneration of the aerogel over three consecutive cycles is studied, exhibiting high reusability with no significant changes in its removal performance. These results point at amyloid fibrils aerogels as a sustainable, efficient, and inexpensive technology for alleviating the ubiquitous water contamination by organic pollutants.


Asunto(s)
Amiloide/química , Geles/química , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Adsorción , Compuestos de Bencidrilo/química , Benzotiadiazinas/química , Ibuprofeno/química , Lactoglobulinas/química , Fenoles/química
19.
Environ Pollut ; 259: 113907, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32023790

RESUMEN

B cells contribute to produce inflammatory cytokines and antibodies, to present autoantigens, and to interact with T cells, which lead to body defense and disease control. Nuclear factor (erythroid-derived 2)-like 2(Nrf2) is responsible for gene expression of antioxidant enzymes to protect cells from oxidative stress by reactive oxygen species(ROS) production. Bisphenol A(BPA) may not be safe due to the effect on body's physiological functions. The chemicals that substitute for BPA may still have similar effects in the body. Tritan™ copolyester is a novel plastic form using BPA substitutes, 1,4-cyclohexanedimethanol(CHDM), dimethyl terephthalate(DMT), and 2,2,4,4-tetramethyl-1,3-cyclobutanediol(TMCD). Isosorbide(ISO) was also used as a substitute for TMCD and DMT. Here, we investigated whether B cell viability is influenced by BPA and its substitutes via Nrf2 induction using WiL2-NS human B lymphoblast cells. When cytotoxicity was measured by using assays with MTT, CellTiter-Glo, trypan blue and propidium iodide, cytotoxicity by BPA was higher than that by substitutes. BPA and its substitutes showed significant cytotoxicity and ROS production, which were attenuated by the treatment with N-acetylcysteine(NAC), a ROS scavenger. In addition, BPA treatment enhanced gene expression of antioxidant enzymes, heme oxygenase(HO)-1, catalase, superoxide dismutase(SOD) 1 and 2. As H2O2 treatment induced cell death and Nrf2 amount in WiL2-NS cells, BPA treatment increased Nrf2. Cell death by H2O2 was increased in doxycycline-inducible Nrf2-knockdown(KD) cells. In Cytotoxicity by the treatment with BPA or its substitutes was also enhanced in Nrf2-KD cells but that was reduced by Nrf2 overexpression compared to control cells. Taken together, these results implicate that B cell cytotoxicity by substitutes should be lower than BPA and Nrf2 can prevent B cells from BPA- or BPA substitutes-induced cytotoxicity via ROS production. Data suggest that the comprehensive studies or evaluation could be necessary to replace BPA in manufacture by other substitutes.


Asunto(s)
Linfocitos B , Compuestos de Bencidrilo , Regulación de la Expresión Génica , Peróxido de Hidrógeno , Factor 2 Relacionado con NF-E2 , Fenoles , Linfocitos B/citología , Linfocitos B/efectos de los fármacos , Compuestos de Bencidrilo/química , Compuestos de Bencidrilo/toxicidad , Supervivencia Celular/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Factor 2 Relacionado con NF-E2/genética , Estrés Oxidativo/efectos de los fármacos , Oxidorreductasas/genética , Fenoles/química , Fenoles/toxicidad , Especies Reactivas de Oxígeno
20.
Chemosphere ; 248: 126053, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32041067

RESUMEN

Nitrogen-containing carbon materials (NCC-x) are promising metal-free catalysts for activation of peroxymonosulfate (PMS) to treat with aqueous organic pollutants. In this study, NCC-x were synthesized via a facile thermal polymerization method using urea and terephthalaldehyde as precursors. This method was derived from the polymerization method of graphitic carbon nitride (g-C3N4) and the reaction between the precursors was based on Schiff base chemistry. Compared with the synthesis of g-C3N4 using urea as the precursor, formation of a melamine ring was inhibited and the cyano groups were produced in NCC-x during the polymerization process. The obtained NCC-x catalysts had high specific surface areas, many graphite-nitrogen active sites, and high degrees of graphitization, thus exhibiting excellent activities for the degradation of bisphenol A via PMS activation. This study introduces a convenient method to obtain a highly efficient nitrogen-containing carbon PMS activator and the results are useful for the development of bisphenol A treatment by PMS activation using carbon-containing materials.


Asunto(s)
Compuestos de Bencidrilo/química , Nitrógeno/química , Peróxidos/química , Fenoles/química , Carbono/química , Catálisis , Contaminantes Ambientales , Grafito , Metales , Compuestos de Nitrógeno , Polimerizacion , Agua
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