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1.
Biosens Bioelectron ; 169: 112604, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32980805

RESUMO

Virus severely endangers human life and health, and the detection of viruses is essential for the prevention and treatment of associated diseases. Metal-organic framework (MOF), a novel hybrid porous material which is bridged by the metal clusters and organic linkers, has become a promising biosensor platform for virus detection due to its outstanding properties including high surface area, adjustable pore size, easy modification, etc. However, the MOF-based sensing platforms for virus detection are rarely summarized. This review systematically divided the detection platforms into nucleic acid and immunological (antigen and antibody) detection, and the underlying sensing mechanisms were interpreted. The nucleic acid sensing was discussed based on the properties of MOF (such as metal ion, functional group, geometry structure, size, porosity, stability, etc.), revealing the relationship between the sensing performance and properties of MOF. Moreover, antibodies sensing based on the fluorescence detection and antigens sensing based on molecular imprinting or electrochemical immunoassay were highlighted. Furthermore, the remaining challenges and future development of MOF for virus detection were further discussed and proposed. This review will provide valuable references for the construction of sophisticated sensing platform for the detection of viruses, especially the 2019 coronavirus.


Assuntos
Técnicas Biossensoriais/métodos , Estruturas Metalorgânicas/química , Viroses/virologia , Vírus/isolamento & purificação , Animais , Anticorpos Antivirais/análise , Antígenos Virais/análise , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Humanos , Imunoensaio/instrumentação , Imunoensaio/métodos , Modelos Moleculares , Impressão Molecular/instrumentação , Impressão Molecular/métodos , Ácidos Nucleicos/análise , Espectrometria de Fluorescência/instrumentação , Espectrometria de Fluorescência/métodos , Viroses/diagnóstico
2.
J Chromatogr A ; 1627: 461387, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823095

RESUMO

A simple and efficient magnetic solid-phase extraction (MSPE) method was established with magnetic covalent organic framework (COF) as adsorbent to enrich organophosphorus pesticides from fatty milk samples, followed by the sensitive determination via LC-MS/MS. The key parameters influencing the MSPE efficiency were comprehensively investigated to afford an optimized procedure. All the target analytes could be captured directly by magnetic COF from milk without protein precipitation, making the pretreatment rapid and convenient. Systematic method validation demonstrated its satisfactory linearity, recoveries (80.0-105 %), and precision (RSDs <12.3 %). The method limits of quantification were 0.2-0.5 µg L-1. A comparison experiment to the reported solid-phase extraction fully verified the present MSPE more rapid, accurate, and environment-friendly. Furthermore, FT-IR and XPS analysis were performed to reveal the adsorption mechanisms of magnetic COF to organophosphorus pesticides, which could offer guidance on the rational design of COF adsorbent for various target analytes.


Assuntos
Fenômenos Magnéticos , Estruturas Metalorgânicas/química , Leite/química , Compostos Organofosforados/análise , Praguicidas/análise , Extração em Fase Sólida/métodos , Acetonitrilos/análise , Adsorção , Animais , Limite de Detecção , Espectroscopia Fotoeletrônica , Padrões de Referência , Reprodutibilidade dos Testes , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier
3.
Ecotoxicol Environ Saf ; 205: 111110, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32810646

RESUMO

ZIF-8 nanoparticles (NPs) has been demonstrated with good potential in drug delivery, which causes an increasing attention on relevant toxicity study. In this work, MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide), glutathione (GSH), reactive oxygen species (ROS), stain analysis and gene detection assays were performed on ZIF-8 (50, 90 and 200 nm) incubated HepG2 cells. Moreover, time-resolved inductively coupled plasma mass spectrometry (TRA-ICP-MS) was applied for single cell analysis; the variation in cellular zinc amount and the proportion of zinc up-taken cells was investigated as a function of NPs size, incubation concentration/time and elimination. Smaller size of ZIF-8 NPs would lead to higher zinc accumulation and toxicity. The function of ZIF-8 on cells is assumed to be mainly related to zinc intracellular accumulation. The possible action path is presented as high accumulation of zinc in ZIF-8 incubated cells lead to high ROS level and cellular inflammation, ultimately inducing necrocytosis. For better understanding of the bio-effect of ZIF-8, ZnO NPs and Zn2+ incubated HepG2 cells were evaluated in the same way. Higher accumulation of zinc in larger part of the cell population was found in ZIF-8 incubated cells than that in ZnO NPs incubated cells. It demonstrated higher bioavailability for ZIF-8 over ZnO NPs. While, in drug delivery application, the possible risk of the remained intracellular ZIF-8 cannot be ignored.


Assuntos
Imidazóis/química , Estruturas Metalorgânicas/toxicidade , Nanopartículas/toxicidade , Óxido de Zinco/toxicidade , Zinco/química , Bioensaio , Disponibilidade Biológica , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Glutationa/farmacologia , Células Hep G2 , Humanos , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/metabolismo , Nanopartículas/química , Tamanho da Partícula , Espécies Reativas de Oxigênio/metabolismo , Análise de Célula Única , Óxido de Zinco/química
4.
J Chromatogr A ; 1626: 461328, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797818

RESUMO

Ferric oxide/carbon (Fe2O3@C) was fabricated via direct carbonization of metal-organic framework of iron (MOF-235) under argon atmosphere. The magnetic Fe2O3 nanoparticles are evenly embedded in porous carbon matrix, while original morphology of MOF-235 was well-maintained. The synthesized Fe2O3@C was used as magnetic sorbent for extracting five benzoylurea insecticides (BUs). The materials exhibited excellent extraction performance, which benefited not only from the strong π-π interaction and hydrophobic interaction (π-conjugated system), but also to the abundant adsorption sites and flexible transport channel (the interconnected 3D porous structure). A three-factor-three-level Box-Behnken design (BBD) was selected to optimize three greatly influential parameters: amount of adsorbent (A), desorption time (B) and volume of desorption solvent (C) by response surface methodology. The established method coupled to HPLC-UV detection showed wide linearity with the range of 0.2-450 µg•L-1, relatively low limits of detection (0.05-0.10 µg•L-1) with the relative standard deviation (RSD) (n = 7) lower t than 5.47%. Moreover, the proposed method was successfully applied to analyze BUs in tea samples and investigate the removal effect of different washing on BUs residues from tea leaf. These results indicated that the synthesized Fe2O3@C is a promising adsorbent material for magnetic solid phase extraction of BUs at trace concentrations from tea samples.


Assuntos
Inseticidas/análise , Nanopartículas de Magnetita/química , Estruturas Metalorgânicas/química , Chá/química , Ureia/análise , Adsorção , Carbono/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida de Alta Pressão/normas , Compostos Férricos/química , Inseticidas/isolamento & purificação , Inseticidas/normas , Limite de Detecção , Porosidade , Padrões de Referência , Extração em Fase Sólida , Espectrofotometria Ultravioleta , Chá/metabolismo , Ureia/análogos & derivados , Ureia/isolamento & purificação , Ureia/normas
5.
J Chromatogr A ; 1626: 461386, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797858

RESUMO

In this study, the microcrystalline cellulose/metal-organic framework 199 hybrid (MCC/MOF-199) was applied as sorbent for the dispersive micro-solid phase-extraction (D-µSPE) of chlorophenols. The D-µSPE method combined with high-performance liquid chromatography- ultraviolet detection (HPLC-UV) was employed to determine of four chlorophenols including 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,3-dichlorophenol (2,3-DCP), and 2,5-dichlorophenol (2,5-DCP) in aqueous. The main parameters of the D-µSPE process that influence the extraction (i.e. the amount of sorbent, elution condition, extraction time, and pH) were investigated and optimized. Based on the outputs, the presence of MCC on the surface of MOF-199 leads to improve the properties of MOF-199 and the MCC/MOF-199 has the highest sorption capacity, durability, and porosity in comparison with MCC and MOF-199. According to the validation study at the optimized conditions, the linearity for the analytes was achieved in the range from 0.1 to 200 ng mL-1 for 2-CP and 4-CP and 0.15 to 200 ng mL-1 for 2,3-DCP and 2,5-DCP with correlation coefficients between 0.9928 and 0.9965. The limits of detection calculated at S/N=3 were in the range of 0.03-0.05 ng mL-1. Besides, the relative standard deviations (RSDs) for three spiking levels (0.2, 10,100 ng mL-1) do not exceed 6.8% and extraction recoveries are between 81.0% and 88.3%. Finally, the D-µSPE-HPLC-UV method was successfully applied to the analysis of CPs in real water samples (mineral, river and wastewater samples) with good recoveries (95.8 to 99.5%) and satisfactory precisions (RSD < 6.8%).


Assuntos
Celulose/química , Clorofenóis/análise , Estruturas Metalorgânicas/química , Microextração em Fase Sólida/métodos , Clorofenóis/química , Clorofenóis/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Água Doce/análise , Concentração de Íons de Hidrogênio , Limite de Detecção , Rios/química , Espectrofotometria Ultravioleta , Águas Residuárias/análise
6.
Ecotoxicol Environ Saf ; 204: 111066, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32781344

RESUMO

In this study, an iron-doped metal-organic framework (MOF) Fe/ZIF-8 was synthesized from ZIF-8 at room temperature. Direct carbonization of Fe/ZIF-8 under a nitrogen atmosphere produced nanoporous nitrogen doped carbon nanoparticles decorated with Fe component (Fe/NC). The Fe/NC exhibited a large surface area (1221.185 m2 g-1) and narrow pore-size distribution (3-5 nm). The nanoporous Fe/NC components along with Nafion were used to modify a glassy carbon electrode for the electrochemical determination of chloramphenicol and metronidazole via linear sweep voltammetry. Under optimal conditions, the reduction peak currents (observed at -0.237 V and -0.071 V vs. Ag/AgCl) of these analytes increased linearly with increasing chloramphenicol and metronidazole concentrations in the range of 0.1-100 µM and 0.5-30 µM, with the detection limits estimated to be 31 nM and 165 nM, respectively. This result was attributed to the large surface area, porous structure, high nitrogen content, and as well as the electrocatalytic effect of Fe atoms embeded in the carbon support. The proposed sensor was used for chloramphenicol and metronidazole analysis in samples, providing satisfactory results.


Assuntos
Carbono/química , Cloranfenicol/análise , Técnicas Eletroquímicas/métodos , Ferro/química , Estruturas Metalorgânicas/química , Metronidazol/análise , Nitrogênio/química , Animais , Cloranfenicol/urina , Eletrodos , Humanos , Limite de Detecção , Metronidazol/urina , Leite/química , Nanoporos , Soluções Oftálmicas/química , Porosidade , Comprimidos/química
7.
J Chromatogr A ; 1626: 461364, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797843

RESUMO

A new type of restricted access media-imprinted nanomaterials (RAM-MIPs) were successfully prepared on the surface of metal-organic framework by reversible addition fragmentation chain transfer polymerization technology. Then it was applied as a dispersed solid phase extraction (DSPE) material in analysis of fluoroquinolones (ofloxacin, pefloxacin, norfloxacin, enrofloxacin and gatifloxacin) in untreated milk and river water by HPLC-UV detection. The resulted material has a good binding amounts (60.81 mg g-1), rapid binding kinetic (15 min) and satisfactory selectivity as well as has a good ability to eliminate matrix interference. Several major factors affecting DSPE efficiency, pH of sample solution, dosage of RAM-MIPs, adsorption time and volume ratios of elution solvent were primarily optimized. In optimization conditions, RAM-MIPs-DSPE was combined with HPLC-UV to enrich fluoroquinolones in untreated milk and river water, achieving satisfactory linear correlation (R2 > 0.9988), good limits of detection (LOD, 1.02-3.15 µg L-1 for milk and 0.93-2.87 µg L-1 for river water) and better recoveries (80.7-103.5% and 85.1-105.9% with relative standard deviation (RSD) of not higher than 5.3% and 4.7% for milk and river water samples, respectively). The research results illustrate that it provides a simple and efficient method for the direct detection of FQs in complex samples.


Assuntos
Antibacterianos/análise , Fluoroquinolonas/análise , Estruturas Metalorgânicas/química , Leite/química , Nanoestruturas/química , Rios/química , Extração em Fase Sólida/métodos , Adsorção , Animais , Antibacterianos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Fluoroquinolonas/isolamento & purificação , Impressão Molecular , Polimerização
8.
J Chromatogr A ; 1628: 461428, 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32822999

RESUMO

A covalent organic framework modified graphitic carbon nitride (g-C3N4@TpBD) was synthesized by modifying the graphitic carbon nitride (g-C3N4) with a covalent organic framework (COF-TpBD). The synthesis conditions including the mass ratio between g-C3N4 and benzidine (BD), solvent type, reaction temperature and reaction time were optimized. Under the optimal synthetic conditions, a novel spiny dendritic g-C3N4@TpBD adsorbent was obtained. The g-C3N4@TpBD was then coated on stainless-steel wire by sol-gel technique and the coated fiber was used for the solid phase microextraction of polycyclic aromatic hydrocarbons prior to gas chromatography-mass spectrometric detection. The established method was successfully applied to determine eight PAHs in six environmental water samples. Under the optimal extraction conditions, a wide linear quantification range for the analytes was obtained from 0.07 to 60.0 ng mL-1 with the coefficients of determination varying from 0.9979 to 0.9998, and the limits of detection (S/N = 3) ranged from 0.02 to 0.05 ng mL-1. The relative recoveries of the analytes for the six environmental water samples at the spiked concentrations of 0.2, 0.5, 3.0 and 30.0 ng mL-1 were between 83.6% and 118% with the relative standard deviations ranging from 2.4% to 11.3%.


Assuntos
Grafite/química , Estruturas Metalorgânicas/química , Compostos de Nitrogênio/química , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação , Microextração em Fase Sólida/métodos , Poluentes Químicos da Água/isolamento & purificação , Benzidinas/química , Limite de Detecção , Reprodutibilidade dos Testes , Temperatura
9.
J Chromatogr A ; 1627: 461395, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823100

RESUMO

Nowadays, enantioseparation of racemic pharmaceuticals in preparations is a prime concern by drug authorities across the globe. In the present work, it was attempted to develop novel enantioselective extraction method for five clinically used drugs (atenolol, propranolol, metoprolol, racecadotril, and raceanisodamine in their tablets) as racemates. The enantioselective solid-liquid extraction of these racemic drugs was carried out successfully by the use of chiral ionic liquid (CIL) in combination with a metal organic framework (MOF) for the first time. The composite CIL@MOF was synthesized from tropine based chiral ionic liquids with L-proline anion ([CnTr][L-Pro], n=3-6) and HKUST-1 type MOF, which was comprehensively characterized before being used as sorbent for enantioselective dispersive solid-liquid extraction. Preliminary selection of appropriate CIL was carried out on thin layer chromatography (TLC); under the joint participation of copper ion in the developing reagent, [C3Tr][L-Pro] ionic liquid showed better resolution performance with ΔRf value of 0.35 between the enantiomers was obtained for racemic atenolol. Moreover, the effect of copper salt dosage, amount of CIL, soli-liquid ratio and extraction time were investigated. The optimal conditions were obtained after thorough investigations; i.e. sample solution: ethanol, elution solvent: methanol, solid-liquid ratio: 12.5 mg:50 mL, amount of copper salt: 8 mg L-1, amount of impregnated CIL: 30% and extraction time of 30 min. As a result, enantiomeric excess values are 90.4%, 95%, 92%, 81.6% and 83.2% for atenolol, propranolol, metoprolol, racecadotril and raceanisodamine, respectively. The developed enantioselective method was validated following ICH guidelines and it was proved to be simple, effective and enantioselective way for separation of racemic pharmaceuticals with similar behaviors.


Assuntos
Líquidos Iônicos/química , Estruturas Metalorgânicas/química , Preparações Farmacêuticas/isolamento & purificação , Extração em Fase Sólida/métodos , Antagonistas Adrenérgicos beta/análise , Antagonistas Adrenérgicos beta/isolamento & purificação , Atenolol/análise , Atenolol/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Cobre/química , Metoprolol/análise , Metoprolol/isolamento & purificação , Preparações Farmacêuticas/análise , Propranolol/análise , Propranolol/isolamento & purificação , Solventes/química , Estereoisomerismo
10.
J Chromatogr A ; 1625: 461275, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709327

RESUMO

Efficient extraction of polar sulfonamides antibiotics from aqueous samples and food is very challenging, because they are hydrophilic, their concentration is very low, and the matrix is complex. Covalent organic frameworks (COFs), a novel porous organic material, have attracted great attention. In this work, the spherical triphenylbenzene-dimethoxyterephthaldehyde-COFs (TPB-DMTP-COFs) were synthesized by a simple room temperature method, and due to their attractive properties, such as high outstanding acid-base stability, large specific surface area, low skeletal density, inherent porosity and high crystallinity, so TPB-DMTP-COFs as ideal solid phase extraction adsorbents showed excellent adsorption performance for trace polar sulfonamides in food and water. TPB-DMTP-COFs were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, powder X-ray diffraction, and so on. The important parameters were optimized to improve the extraction efficiency of TPB-DMTP-COFs toward sulfonamides. Analysis of sulfonamides was performed by liquid chromatography-tandem mass spectrometry. The developed method based on TPB-DMTP-COFs material achieved low limits of detection (0.5-1.0 ng L-1), wide linearity (5-1000 ng L-1), and good repeatability (2.5%-8.7%). The possible extraction mechanism was also discussed. Finally, the method was successfully applied to the enrichment and detection of sulfonamides in environmental water samples and food samples. The present study indicated that TPB-DMTP-COFs had splendid prospects in highly sensitive analysis of other pollutants in complex matrix.


Assuntos
Análise de Alimentos , Estruturas Metalorgânicas/química , Extração em Fase Sólida/métodos , Sulfonamidas/análise , Espectrometria de Massas em Tandem/métodos , Poluentes Químicos da Água/análise , Adsorção , Animais , Cromatografia Líquida , Contaminação de Alimentos/análise , Leite/química , Carne de Porco/análise , Porosidade , Sulfonamidas/química , Água/química
11.
J Chromatogr A ; 1625: 461337, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709361

RESUMO

Monitoring the levels of perfluorinated compounds (PFCs) in the environment is of vital importance, owing to their sustained environmental presence, extensive distribution, and associated health risks. The development of cost-effective and efficient sorbents for the establishment of sensitive analytical methods is critical for achieving trace-level detection. In this study, a graphitic carbon nitride (g-C3N4)-based sorbent is synthesized by a facile sonication-assisted method exfoliated by zeolitic imidazolate framework-67 (ZIF-67) in situ. The novel ZIF-67/g-C3N4 composites were systematically characterized by transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and N2 adsorption-desorption analysis, exhibiting good dispersity and a large surface area. Moreover, molecular dynamics simulations indicated that g-C3N4 structures can be effectively exfoliated by the introduced ZIF-67 molecules. The hybrid material was successfully utilized as a dispersive solid-phase extraction sorbent, and the extraction factors were systematically optimized by response surface methodology. Under optimal conditions, the synthesized sorbent exhibited desirable linear correlations (R2 > 0.99), a low detection limit (0.3-2 ng L-1), and good repeatability (relative standard deviation <15%, n = 6). The developed method was applied for the analysis of natural and spiked water samples. The study demonstrated that the ZIF-67/g-C3N4 composites are promising materials for pollutant adsorption from drinking water samples.


Assuntos
Água Potável/química , Fluorcarbonetos/análise , Grafite/química , Estruturas Metalorgânicas/química , Compostos de Nitrogênio/química , Extração em Fase Sólida/métodos , Sonicação , Poluentes Químicos da Água/análise , Adsorção , Simulação de Dinâmica Molecular
12.
Food Chem ; 332: 127427, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32619936

RESUMO

A magnetic porous organic framework (M-POF) was rationally designed and served as a sorbent for magnetic solid-phase extraction of six nitroimidazoles from chicken meat prior to their assay by high-performance liquid chromatography with diode array detection. The M-POF exhibited good magnetic responsiveness and outstanding affinity to nitroimidazoles with large adsorption capacity up to 36 mg g-1. Under optimal conditions, the developed method offered good linearity (r greater than 0.992) in the range of 1.5-100.0 ng g-1, low limits of detection (S/N = 3) of 0.5-0.8 ng g-1, low limits of quantification of 1.5-2.5 ng g-1 and high enrichment factors of 80-175 for the nitroimidazoles. The method was successfully applied to analyze nitroimidazoles in chicken meat. The recoveries were 80.2-118% with relative standard deviations lower than 12%. The adsorption mechanism was further explored and the results showed that the M-POF exhibited adsorption potential for compounds with strong polar interactions.


Assuntos
Antibacterianos/isolamento & purificação , Contaminação de Alimentos/análise , Magnetismo/métodos , Carne/análise , Estruturas Metalorgânicas/química , Nitroimidazóis/isolamento & purificação , Extração em Fase Sólida/métodos , Adsorção , Animais , Antibacterianos/análise , Bioensaio , Galinhas , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Magnetismo/instrumentação , Músculo Esquelético/química , Nitroimidazóis/análise , Porosidade , Extração em Fase Sólida/instrumentação
13.
Chemosphere ; 260: 127583, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32698115

RESUMO

A series of superhydrophobic polycarbonate porous monoliths modified with metal organic framework (Z8/PC) were firstly fabricated through a facile thermally impacted non-solvent induced phase separation method for efficient selective oil/water separation. The performance of the monoliths on oil/water separation was evaluated in terms of selectivity, equilibrium adsorption capacity, corrosion resistance, kinetics, and circulation. The results showed that the use of ZIF-8 significantly compensated for the shortage of pure monolith. Compared with pure PC monolith, the hydrophobic angle of the Z8/PC-2 monolith promoted from 136.18° to 154.25° due to the micro-nano flower surface. Meanwhile, the Z8/PC-2 monolith displayed a more intricate and continuous interconnected 3D hierarchical micro-nano structure, which possessed the monolith a higher specific surface area of 146.84 m2 g-1 and porosity of 89.5%. What's more, more superior oil/water separation abilities of Z8/PC-2 monolith were manifested by the selective removal of oil or organic solvent from water within 30s, high equilibrium adsorption capacity, and excellent corrosion resistance. In addition, the ten-cycle regeneration of porous monoliths via centrifugation or evaporation displayed additional attractiveness. Therefore, porous Z8/PC monolith will be a promising candidate for the efficient selective oil/water separation of oil spills and organic solvents.


Assuntos
Estruturas Metalorgânicas/química , Nanoestruturas/química , Poluição por Petróleo/análise , Cimento de Policarboxilato/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Zinco/química , Adsorção , Interações Hidrofóbicas e Hidrofílicas , Modelos Teóricos , Porosidade
14.
Int J Mol Sci ; 21(14)2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32698479

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the COVID-19 pandemic that has been spreading around the world since December 2019. More than 10 million affected cases and more than half a million deaths have been reported so far, while no vaccine is yet available as a treatment. Considering the global healthcare urgency, several techniques, including whole genome sequencing and computed tomography imaging have been employed for diagnosing infected people. Considerable efforts are also directed at detecting and preventing different modes of community transmission. Among them is the rapid detection of virus presence on different surfaces with which people may come in contact. Detection based on non-contact optical techniques is very helpful in managing the spread of the virus, and to aid in the disinfection of surfaces. Nanomaterial-based methods are proven suitable for rapid detection. Given the immense need for science led innovative solutions, this manuscript critically reviews recent literature to specifically illustrate nano-engineered effective and rapid solutions. In addition, all the different techniques are critically analyzed, compared, and contrasted to identify the most promising methods. Moreover, promising research ideas for high accuracy of detection in trace concentrations, via color change and light-sensitive nanostructures, to assist fingerprint techniques (to identify the virus at the contact surface of the gas and solid phase) are also presented.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/diagnóstico , Estruturas Metalorgânicas/química , Nanotecnologia/métodos , Pneumonia Viral/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito , Genoma Viral/genética , Humanos , Nanopartículas Metálicas/química , Pandemias , RNA Viral/genética , Sequenciamento Completo do Genoma
15.
J Chromatogr A ; 1623: 461197, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505286

RESUMO

Trifluoromethyl covalent organic framework (CF3-COF) is facilely synthesized at room temperature using for solid-phase microextraction (SPME). The CF3-COF coating displays an improved extraction performance for per- and polyfluorinated alkyl substances (PFASs) comparing to amorphous polymer coating, non-contained fluorine covalent organic framework coating and commercially available SPME coating. The fluorine affinity of trifluoromethyl in CF3-COF for PFASs is demonstrated using the density functional theory calculation. Following the microextraction with CF3-COF-coated fiber, the targeted PFASs are eluted with 1 mL acetonitrile and quantified by ultrahigh performance liquid chromatography tandem mass spectrometry. The low limits of detection are 0.1-0.7 pg g-1 for milk and 0.2-0.8 pg g-1 for milk powder, suggesting the outstanding sensitivity. The precision for the method ranges between 2.9 and 9.9%. The fiber-to-fiber repeatability is in the range of 4.2-9.5%. Under the optimum conditions, the relative recoveries are 91.0-110% with RSDs ≤ 10% for milk and 89.8-111% with RSDs ≤ 10% for milk powder.


Assuntos
Hidrocarbonetos Halogenados/isolamento & purificação , Estruturas Metalorgânicas/química , Leite/química , Microextração em Fase Sólida/métodos , Adsorção , Animais , Citrullus/química , Sucos de Frutas e Vegetais/análise , Glioxal/química , Concentração de Íons de Hidrogênio , Estruturas Metalorgânicas/síntese química , Fenóis/química , Reprodutibilidade dos Testes , Resinas Sintéticas/química , Ureia/química
16.
J Chromatogr A ; 1623: 461198, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505287

RESUMO

Microcystins (MCs) and nodularin (NOD) are tumor promoters produced by cyanobacteria and present in surface water. In this work, a novel mesoporous metal-organic framework-5@chitosan (MOF-5@CS) material was synthesized and applied for the enrichment of MCs and NOD in water and fish samples. The mesoporous MOF-5@CS material was firstly synthesized via a one-step hydrothermal method, and the chitosan was combined with MOF-5 via chemical bonding assembly. As a new adsorbent, the as-synthesized material was found having a large specific surface area and good thermal stability. Under the optimized conditions, MCs and NOD were enriched by the MOF-5@CS material and detected by ultra-performance liquid chromatography-tandem mass spectrometry. The limit of detection of the new method for MCs and NOD were in the range of 0.0018-0.077 ng/mL. The value of relative standard deviation for repeatability were 2.69-6.30%, and the recovery of the analytes ranged from 84.36% to 118.51%. Compared with other reported method for MCs and NOD detection in complex matrices, better adsorption performance for MCs and NOD were obtained by our new method, and the sensitivity of MCs-RR and NOD were improved nearly 20 times and 30 times, respectively.


Assuntos
Quitosana/química , Cromatografia Líquida de Alta Pressão/métodos , Estruturas Metalorgânicas/química , Microcistinas/análise , Peptídeos Cíclicos/análise , Espectrometria de Massas em Tandem/métodos , Adsorção , Microcistinas/química , Peptídeos Cíclicos/química , Padrões de Referência , Reprodutibilidade dos Testes , Extração em Fase Sólida , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise
17.
Food Chem ; 330: 127212, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32526650

RESUMO

In this work, a facile solid phase extraction (SPE) method was developed for the analysis of trace Pb2+ and Cd2+ by using chitosan/thiol modified metal-organic frameworks (CS/MOF-SH) composite as adsorbent followed by graphite furnace atomic absorption spectrometer (GF-AAS) detection. The potential influencing factors, such as solution pH, adsorbent dosage, and extraction time, were fully estimated. Under the optimized extraction conditions, the detection limits of Pb2+ and Cd2+ were 0.033 µg L-1 and 0.008 µg L-1, respectively. Compared to other studies, CS/MOF-SH not only possessed superior adsorption performance, but also had the advantages of ease of handling and recyclability. Encouragingly, the developed method was of high accuracy and could monitor trace Pb2+ and Cd2+ in various certified reference materials (rice, wheat and tea) with complicated matrices, demonstrating its practical potential for regular monitoring of trace heavy metal ions in real food samples.


Assuntos
Cádmio/análise , Quitosana/química , Chumbo/análise , Estruturas Metalorgânicas/química , Compostos de Sulfidrila/química , Cádmio/química , Cátions Bivalentes , Análise de Alimentos , Chumbo/química , Oryza/química , Extração em Fase Sólida/métodos , Chá/química , Triticum/química
18.
Nat Commun ; 11(1): 3080, 2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32555154

RESUMO

The exact chemical structure of non-crystallising natural products is still one of the main challenges in Natural Sciences. Despite tremendous advances in total synthesis, the absolute structural determination of a myriad of natural products with very sensitive chemical functionalities remains undone. Here, we show that a metal-organic framework (MOF) with alcohol-containing arms and adsorbed water, enables selective hydrolysis of glycosyl bonds, supramolecular order with the so-formed chiral fragments and absolute determination of the organic structure by single-crystal X-ray crystallography in a single operation. This combined strategy based on a biomimetic, cheap, robust and multigram available solid catalyst opens the door to determine the absolute configuration of ketal compounds regardless degradation sensitiveness, and also to design extremely-mild metal-free solid-catalysed processes without formal acid protons.


Assuntos
Produtos Biológicos/química , Hidrolases/química , Estruturas Metalorgânicas/química , Adsorção , Álcoois/química , Catálise , Cristalografia por Raios X , Glicólise , Hidrólise , Cinética , Metais , Conformação Molecular , Estrutura Molecular , Porosidade , Relação Estrutura-Atividade , Difração de Raios X
19.
Food Chem ; 328: 127105, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32464556

RESUMO

Synthetic dyes have been widely applied to food processing, but abuse of colourants in food may pose risks to human health. To analyze new coccine (NC) and orange II (OII) in food, a versatile surface-enhanced Raman scattering (SERS) platform was proposed. A metal-organic framework (MOF, UiO-66(NH2)) with octahedral crystal structure was synthesized and gold nanoparticles were grown on the MOF surface to fabricate UiO-66(NH2)@Au versatile SERS platform. The UiO-66(NH2)@Au displayed much better SERS performance than gold nanoparticles with high R2 of 0.9684 for NC and 0.9912 for OII and low LOD of 0.4015 mg/L for NC and 0.0546 mg/L for OII. The recoveries of NC and OII in Mirinda soft drink and paprika ranged from 82.92 to 109.63%. This study provided a sensitive and rapid method for determination of NC and OII through UiO-66(NH2)@Au, and the proposed SERS platform revealed great potential for analyzing synthetic colourants in food samples.


Assuntos
Compostos Azo/análise , Benzenossulfonatos/análise , Análise de Alimentos/métodos , Nanopartículas Metálicas/química , Estruturas Metalorgânicas/química , Naftalenossulfonatos/análise , Análise Espectral Raman/métodos , Adsorção , Corantes/análise , Ouro/química , Limite de Detecção
20.
Artigo em Inglês | MEDLINE | ID: mdl-32400276

RESUMO

Herein, we report a novel composite material of Nb2O5@MIL-125 that exhibited enhanced photoreduction of hexavalent chromium. The composite material was fabricated through an impregnation approach, which comprised of a two-step hydrothermal synthesis. As-prepared Nb2O5 nanospheres exhibited very poor charge separation; MIL-125 (Ti) which is a Ti-based metal-organic framework was introduced into the lattice of the spheres to improve charge recombination rate. The synthesized material's phase, crystallinity, textural and morphological studies were investigated utilizing XRD, Raman, TEM, SEM, and EDS, respectively. While the optical and photoelectrochemical behavior of the samples were obtained from UV-vis-DRS, PL, and EIS data. This data combined, illustrated the successful formation of a functional and effective heterointerface between Nb2O5 and MIL-125 (Ti). Ti introduced as the MOF in the lattice of Nb2O5 had an essential synergetic effect as the composite bearing the highest mole ratio of Ti showed higher effective photoreduction of hexavalent chromium. This was further complemented the PL and XPS data which highlighted the Nb-MIL-125 (2-3) composite to have excellent charge separation and rapid photoreduction of chromium.


Assuntos
Cromo/análise , Estruturas Metalorgânicas/química , Nióbio/química , Óxidos/química , Titânio/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Catálise , Luz , Oxirredução , Fotoquímica
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