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1.
Food Chem ; 366: 130594, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34303207

RESUMO

In this work, a single-emission, dual-enzyme immunofluorometric magnetosensor was fabricated to simultaneously detect three illegal colorants in chili seasoning. Specifically, two enzymatic reactions catalyzed by horse radish peroxidase-labeled Rhodamine (RhB) antibody and glucose oxidase-labeled Sudan dyes (SuDs) antibody were performed within a functional microfluidic chip, leading to production of strongly fluorescent Resorufin. In addition, a compact analyzer assisted by a smartphone was developed to quantify signals. Compared with the available multiplex optical biosensors, this work demonstrated four superiorities: 1) Simple optical structure. Only single wavelength excitation/emission module was needed; 2) High multiplexing capacity through spatial resolution and signal resolution; 3) Precise determination by discriminant analysis; 4) Easy-operated and high-throughput parallel detection on 16-channel chips. Ultralow detection limits for RhB (0.0072 ng/mL), Sudan I (0.0040 ng/mL) and Sudan II (0.0260 ng/mL) were obtained by this magnetosensor, which opens a new approach in field detection of multiplex illegal dyes in food system.


Assuntos
Corantes , Fluorimunoensaio
2.
Food Chem ; 367: 130660, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34390907

RESUMO

In this work, a quantitative image analysis method based on cyanine dye-upconversion nanoparticles composite luminescent nanoprobe for the detection of nitrite was developed. The nanoprobe was constructed by combining the NaYF4:Yb,Tm@NaYF4 upconversion nanoparticles (UCNPs) and the new cyanine dye IR-790. The upconversion nanoparticles transferred energy to IR-790, resulting in the luminescence quenching, while the luminescence of UCNPs was recovered after adding NO2-. The increase in photons was related to the concentration of NO2-. Under the optimal experimental conditions, the detection range was 0.20-140 µM and the limit of detection was 0.030 µM. The measurement for NO2- can be completed in 29 min. The method has the characteristics of fast response (~0.1 s), low sample consumption (10 µL) and powerful data support (550 frame time series images). Furthermore, the quantitative image analysis method was successfully applied for the analysis of nitrite in environmental water and food samples.


Assuntos
Luminescência , Nanopartículas , Corantes , Nitritos
3.
World J Gastroenterol ; 27(36): 5989-6003, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34629815

RESUMO

Laparoscopic cholecystectomy (LC) is one of the most frequently performed gastrointestinal surgeries worldwide. Bile duct injury (BDI) represents the most serious complication of LC, with an incidence of 0.3%-0.7%, resulting in significant perioperative morbidity and mortality, impaired quality of life, and high rates of subsequent medico-legal litigation. In most cases, the primary cause of BDI is the misinterpretation of biliary anatomy, leading to unexpected biliary lesions. Near-infrared fluorescent cholangiography is widely spreading in clinical practice to delineate biliary anatomy during LC in elective and emergency settings. The primary aim of this article was to perform an up-to-date overview of the evolution of this method 12 years after the first clinical application in 2009 and to highlight all advantages and current limitations according to the available scientific evidence.


Assuntos
Doenças dos Ductos Biliares , Colecistectomia Laparoscópica , Colangiografia , Colecistectomia Laparoscópica/efeitos adversos , Corantes , Humanos , Qualidade de Vida
4.
J Contemp Dent Pract ; 22(7): 812-828, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34615789

RESUMO

AIM: The assessment of hyalinization to determine aggressive behavior in oral pathological lesions is a scarcely researched field that requires further exploration. The current study aims to predict the biological behavior of oral hyalinizing extraosseous lesions (OHEOL) by employing four differential stains with clinicopathologic correlation. MATERIALS AND METHODS: The study was performed on retrospectively diagnosed formalin-fixed paraffin-embedded cases of salivary gland tumors (SGTs) (n = 13), benign soft tissue (BST) lesions (n = 24), and oral submucous fibrosis (OSMF) (n = 53). The hematoxylin and eosin-stained sections were analyzed for the severity of hyalinization (SOH). Differential stains periodic acid Schiff (PAS), Alcian blue, safranin O, and picrosirius red with polarizing microscopy were used to assess the components of hyalinized tissue. The SOH was correlated with differential staining characteristics and clinicopathologic features to analyze possible correlation with aggressive potential in BST, advancement of disease in OSMF, and recurrence in SGT. RESULTS: Intensity of picrosirius red stain significantly correlated with SOH of SGTs (p = 0.044). The intensity of PAS stain (p = 0.040), picrosirius red polarizing greenish-yellow color (p = 0.002), and pattern of distribution of picrosirius red (p = 0.023) significantly correlated with recurrence of SGTs. The intensity of differential stains increased with the SOH in BST lesions indicating their correlation with SOH. The intensity (p = 0.008) and pattern (p = 0.010) of Alcian blue staining and intensity of safranin O stain (p = 0.003) significantly correlated with SOH in OSMF. Picrosirius red polarizing color reddish and yellowish red (p = 0.002) significantly correlated with SOH distinguishing early and advanced OSMF. CONCLUSION: Picrosirius red and PAS stains are reliable indicators of SOH and recurrence potential in SGT. Alcian blue, safranin O, and picrosirius red polarizing colors enable detection of SOH and accurately distinguish early from advanced OSMF. CLINICAL SIGNIFICANCE: SOH can be considered as a histological predictor of aggressive biologic behavior in OHEOL. These findings will result in appropriate management protocols.


Assuntos
Corantes , Microscopia , Estudos Retrospectivos , Coloração e Rotulagem
5.
Anal Chim Acta ; 1182: 338953, 2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34602199

RESUMO

This work describes the development of a miniaturized paper-based pH detection platform using natural dye extracted from red cabbage (Brassica oleracea). The easily available paper was used as a substrate and the requisite patterned zone was created with the aid of a punching machine. Experimental parameters were optimized to obtain the best signal readout. The performance of the device at different pH values was quantitatively assessed using digital image analysis with various color space models. Regression analysis suggested that a∗ parameter in CIEL∗a∗b∗ color space model, which captures the variations on the red-green scale, exhibited the best fit with experimental data (R2 = 0.9754). This parameter was used for the quantitative estimation of pH variations in a wide range of pH (1-12). A series of real test samples were examined using the paper-based device and results validated with a standard pH meter. The use of paper and natural dye makes the device eco-friendly. The simplicity of fabrication, ease of usage and low reagent and sample volume requirements render the methodology suitable for in situ measurements of pH. The approach demonstrated here would pave the way for the development of clean, sustainable and intensified chemical sensor technologies.


Assuntos
Corantes , Concentração de Íons de Hidrogênio
6.
Water Sci Technol ; 84(5): 1146-1158, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34534112

RESUMO

A novel copper doped graphitic carbon nitride (Cu-C3N4) was successfully synthesized and used as an effective Fenton-like catalyst. Cu-C3N4 was characterized by scanning electron microscopy, surface area analyzer, Fourier transform infrared spectroscopy, X-ray diffractometer, and X-ray photoelectron spectroscopy. Effect of process parameters including catalyst dosage, hydrogen peroxide (H2O2) concentration, solution pH, and initial methylene blue (MB) concentration was investigated to evaluate catalytic performance. The pseudo first-order kinetic model was used to describe the catalytic process. The enhancement of MB degradation is observed assisted by ultrasound. MB degradation of 96% is obtained within 30 min in Cu-C3N4/H2O2/ultrasound system, and the corresponding rate constant is 0.099 min-1. Effective MB degradation is obtained over a broad pH range (3.3-9.9). The catalytic mechanism is examined by ultraviolet-visible spectra, quenching test, and electron spin resonance determination. The dominant mechanism of MB degradation is ascribed to the ultrasonic H2O2 activation by Cu-C3N4 for hydroxyl radical generation. Cu-C3N4 has good reusability and is effective to degrade rhodamine B and acid orange 7. This work not only contributes to the field of wastewater treatment, but also provides insights into the synthesis of Fenton-like catalysts. The results manifest that Cu-C3N4 is a promising Fenton-like catalyst for dye degradation in the field of environmental pollution remediation.


Assuntos
Corantes , Peróxido de Hidrogênio , Cobre , Grafite , Compostos de Nitrogênio
7.
Water Sci Technol ; 84(5): 1217-1227, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34534118

RESUMO

Published literature describes the formation of the Fe (II)-phenanthroline complex (ferroin) as a stop way for Fenton processes, reducing radical yield. By contrast, this study presents evidence that ferroin can be activated by UVA in mildly acidic media in a photo-Fenton-like process. Because ferroin is the main waste from total iron determination in environmental samples, a recycling approach is suggested. Based on the best practices of waste management planning, an application of the proposed method for treating another chemical waste is presented. Titrimetric ammonia determination waste containing 2.67 mg L-1 methyl red azo dye and 1.33 mg L-1 methylene blue was degraded using the optimized experimental conditions: pH = 5.2-5.4; [H2O2] = 310 mg L-1; [ferroin] = 1.4 mg L-1; temperature = 36 ± 1 °C; reaction time = 165 min under UVA irradiation. Attenuation of most intense spectroscopic bands for the dyes achieved 94% (510 nm) and 96% (665 nm) reduction for methyl red and methylene blue, respectively, with degradation of ferroin itself. The present work brings empirical evidence that is possible to recycle ferroin as photo-Fenton-like process catalyst, as well as determine the best conditions for providing less acidic treated effluents with negligible suspended solid concentration, better than that obtained from classical photo-Fenton processes.


Assuntos
Corantes , Poluentes Químicos da Água , Peróxido de Hidrogênio , Oxirredução , Fenantrolinas
8.
Sci Total Environ ; 792: 148546, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34465057

RESUMO

During the latest several decades, the continuous development of the economy and industry has brought more and more serious organic pollutants to the natural environment, which have inevitably aroused severe menace to human health and the environmental system. The nano zero-valent iron (NZVI) particles and NZVI-based materials have widely applied to remove organic pollutants. This article reviews the key advancements of different methods for the synthesis of NZVI and NZVI-based materials. Different modification methods (e.g., doped NZVI, encapsulated NZVI and supported NZVI) are also introduced detailedly for overcoming the defects of NZVI such as aggregation and easy oxidation. The removal of different organic pollutants including dyes, halogenated organic compounds, nitro-organic compounds, phenolic compounds, pesticides, and antibiotics are summarized. The interaction mechanisms, including adsorption, reduction, and active oxidation of organic pollutants by NZVI/NZVI-based composites, are discussed. The dyes are mainly removed by destroying their chromogenic group according to the reduction or the Fenton-like reaction with NZVI. The removal of halogenated organic compounds (HOCs) is realized by the dehalogenation process, including reductive elimination, hydrogenolysis, and hydrogenation. As for the nitro-organic compounds, three different reduction pathways as nitro-reduction (into amino), cleavage at the carbon­nitrogen bond or denitration of the NO2 group may take effect. The phenolic compounds can be mineralized into inorganic molecules, including CO2 and H2O, by Fenton oxidation. This review might provide the basis for future studies on developing more effective NZVI-based materials for the treatment of wastewaters contaminated by organic pollutants.


Assuntos
Ferro , Poluentes Químicos da Água , Adsorção , Corantes , Humanos , Águas Residuárias , Poluentes Químicos da Água/análise
9.
J Hazard Mater ; 416: 125864, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492812

RESUMO

Reactive red 2 (RR2) is a highly recalcitrant and toxic azo dye that can cause the collapse of biological treatment system. Although MFC can decolorize RR2 effectively, its performance is still inevitably affected by toxicity. Anthraquinone can enhance MFCs' performance through mediating electron transfer. In this study, an anthraquinone-rich natural plants (B.rheum (Rheum offcinale Baill)) was extracted and then added to MFCs. The optimal dosage was selected and the enhanced effects were investigated. The results showed that adding 5%(V/V) extract resulted in the optimal performance elevation of MFC. When 5% extract was added together with RR2, 15.63% and 1.33-fold improvement in RR2 decolorization efficiency and rate were achieved compared with the control group. Meanwhile, higher power density (2.75 W/m3), coulombic efficiency (6.45%), and lower internal resistance (233.69 Ω) were also observed when 5% B.rheum extract and RR2 were added. B.rheum extract in MFCs enhanced microbial activity and enriched the dye-degrading microorganisms, such as Enterobacter, Raoultella, Comamonas and Shinella. B.rheum extract acts as "antidote" in alleviating the biotoxicity of RR2 was firstly illustrated in this study. The results provided a new strategy for using plant-source electron mediators to simultaneously improve biological detoxification, bioelectricity generation and dye decolorization in bioelectrochemical system.


Assuntos
Compostos Azo , Fontes de Energia Bioelétrica , Compostos Azo/toxicidade , Corantes/toxicidade , Eletricidade , Eletrodos , Transporte de Elétrons , Elétrons
10.
J Hazard Mater ; 416: 125897, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492835

RESUMO

Interconnected macro-porous cryogels with robust and pore-tunable structures have been fabricated using chemically crosslinked microfibrillated cellulose (MFC). Periodate oxidation was initially conducted to introduce aldehyde groups into the MFC surface, followed by the freeze-induced chemical crosslinking via the formation of hemiacetal bonds between aldehyde and hydroxyl at -12 °C. The cryogels with pore-tunable structures and sharply enhanced mechanical strengths were finally achieved by re-assembly of MFCs through soaking in NaIO4 solution. Furthermore, the MFC cryogels were post-crosslinked by polyethyleneimine (PEI), bestowing the cryogels with the capability of adsorbing anionic dyes. The stress of the PEI-MFC cryogel at the 80% strain was determined to be 304.5 kPa, which is the maximum value for the nanocellulose-based cryogels reported so far. Finally, the adsorption performances of PEI-MFC cryogels for methyl orange (MO) were evaluated. Maximum adsorption capacity of 500 mg/g could be obtained by the Langmuir model, outperforming that of previous absorbent materials. Reuse experiments indicated that over 90% of adsorption capacity was retained after 6 cycles. Continuous clean-up experiments demonstrated excellent MO removal abilities of the PEI-MFC cryogel. This study shows that the novel, green strategy to fabricate the robust cryogel extends the practical applications of nanocellulose adsorbents for environmental remediation.


Assuntos
Criogéis , Nanofibras , Adsorção , Compostos Azo , Celulose , Corantes , Porosidade
11.
Nanoscale ; 13(37): 15569-15575, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34519326

RESUMO

Near-infrared two-zone (NIR-II) fluorescence imaging has attracted attention as a non-invasive imaging technology that provides centimeter-level depth and micron-level resolution. However, producing a NIR-II fluorescent nanoprobe with uniform size, high bio-identical capacity, and fluorescence intensity, while being metabolizable in vivo, remains a challenge. We first produce a hydrophobic NIR-II fluorescent molecule with AIE properties, and subject it to ultrasonic and extrusion treatments to generate a DSPE-PEG-encapsulated NIR-II nanoprobe with an ultra-homogeneous particle size. The current study based on in vitro and mouse tumor-bearing model-based experiments indicate that cancer cells could efficiently take up this nanoprobe, which aggregates in tumor tissues, is susceptible to metabolization, and enables ideal photothermal therapeutic effects. Thus, this NIR-II nanoprobe with AIE properties shows great potential for precise clinical diagnosis and treatment of cancer.


Assuntos
Terapia Fototérmica , Neoplasias da Próstata , Animais , Corantes , Fluorescência , Corantes Fluorescentes , Humanos , Masculino , Camundongos , Imagem Óptica , Tamanho da Partícula , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/terapia
12.
Vet Clin Pathol ; 50(3): 404-409, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34472131

RESUMO

Although oral cytology using Papanicolaou stain is useful for the early detection of oral premalignant lesions and squamous cell carcinoma (SCC) in people, little work has been conducted on this topic in veterinary medicine. This paper describes the features of oral cytology using Papanicolaou stain and immunocytochemistry on liquid-based cytology slides in a case of oral SCC in an Indo-Pacific bottlenose dolphin (Tursiops aduncus). In this case, dysplastic cells with koilocyte-like changes and SCC cells were identified using the Papanicolaou stain. These cells were positive for p53 using an immunocytochemistry analysis. A cytologic diagnosis of SCC was made. We believe that the early detection of premalignant oral lesions and SCC in dolphins can be significantly improved with cytology using liquid-based cytology, Papanicolaou staining, and immunocytochemistry.


Assuntos
Golfinho Nariz-de-Garrafa , Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Animais , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/veterinária , Corantes , Neoplasias de Cabeça e Pescoço/veterinária , Imuno-Histoquímica , Neoplasias Bucais/diagnóstico , Neoplasias Bucais/veterinária , Carcinoma de Células Escamosas de Cabeça e Pescoço/veterinária
13.
J Hazard Mater ; 416: 125929, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492859

RESUMO

A cobalt oxide graphene nanocomposite functionalized with polypyrrole (COPYGO) having a heterogenous porous structure was synthesized using hydrothermal method. Microscopic imaging of the COPYGO surface revealed its highly porous and ordered features. The adsorption performance of the COPYGO composite was systemically investigated for Methylene Blue (MB), Congo red (CR) dyes and toxic lead (Pb(II)) and Cadmium (Cd(II)) metals. These were selected as they are the common pollutants in industrial wastewater. The COPYGO was found to be thermally stable up to 195 oC with a specific surface area of 133 m2 g-1. Experimental data indicates that the COPYGO follows Langmuir and Temkin adsorption isotherm. The COPYGO was efficient in removing MB (92.8%), CR (92.2%), Pb(II) (93.08%) and Cd(II) (95.28%) pollutants at pH 7.2, 5.0, 5.5 and 6.1 respectively from the simulated effluents. The maximum adsorption capacity (Qmax) observed for MB 663.018 mg g-1, CR 659.056 mg g-1, Pb(II) 780.363 mg g-1 and Cd(II) 794.188 mg g-1 pollutants. The thermodynamic analysis of the COPYGO indicates that the adsorption is endothermic and spontaneous in nature. COPYGO showed very high efficient removal rate for the pollutants in simulated effluents which guaranteed its benefits and efficacy in industrial wastewater treatment.


Assuntos
Poluentes Ambientais , Grafite , Metais Pesados , Nanocompostos , Poluentes Químicos da Água , Adsorção , Cobalto , Corantes , Cinética , Óxidos , Polímeros , Pirróis , Poluentes Químicos da Água/análise
14.
J Hazard Mater ; 416: 126195, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492959

RESUMO

The fluorescent emission wavelengths of nanostructures derived from bulk graphitic carbon nitride were commonly lower than those of their bulk due to the quantum confinement effect, which are disadvantageous for bioimaging and sensing applications. Herein, a new strategy to engineer graphitic carbon nitride nanomaterials with tunable fluorescent wavelength and intensity was proposed via thermal treatment of bulk graphitic carbon nitride at high temperature and then hydrolysis in alkali solution. Highly fluorescent g-C3N4 nanobelts with emission peak at 494 nm, 19 nm higher than that of bulk graphitic carbon nitride and 23.6% quantum yield were successfully obtained by controlling the heating temperature at 750 °C for 2 h and the hydrolysis in 4 mol L-1 NaOH solution for 8 h. Finally, a home-made portable gas sensor for reversibly sensing of toxic NO2 gas at room temperature was designed by utilizing graphitic carbon nitride nanobelts as the fluorescent nanoprobe, which can overcome the disadvantages of high operation temperature or the interference of humidity resulting from the common chemiresistive sensors.


Assuntos
Nanoestruturas , Dióxido de Nitrogênio , Corantes , Temperatura
15.
Anal Chem ; 93(38): 12944-12953, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34523923

RESUMO

For sensing low abundance of biomarkers, utilizing nanocarriers to load dyes is an efficient method to amplify the detected signal. However, the non-specific leak of the internal dyes in this approach is accompanied by false positive signals, resulting in inaccurate signal acquirement. To address this issue, in this work, we reported a novel signal amplification strategy with dye as a scaffold to construct a self-immolative dye-doped polymeric probe (SDPP). In our proposed approach, the dyes were covalently integrated into the main chain of a polymer, which can avoid the non-specific leak of the dye when used in a rigorous biological environment, thus evading the false positive signal. As a prototype of this concept, a SDPP, which responds to hydroxyl radicals (•OH), was rationally fabricated. Upon being activated by •OH, SDPP will liberate the dye through a self-immolative reaction to bind with protein for amplifying the fluorescence signal. Compared with a dye-loaded nanoprobe, SDPP can precisely track intracellular basal •OH levels and visualize the •OH associated with myocarditis in vivo. More importantly, the attempt in this work not only provides an effective molecular tool to investigate the role of •OH in cardiopathy, but also puts forward a new direction to current signal-amplifying strategies for precisely and reliably acquiring the intracellular molecular information.


Assuntos
Corantes , Radical Hidroxila , Diagnóstico por Imagem , Corantes Fluorescentes , Polímeros , Espectrometria de Fluorescência
16.
J Environ Manage ; 299: 113589, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34467861

RESUMO

In this study, two multifunctional nano-chitosan flocculants (CPAM-NCS1 and CPAM-NCS2) were made through the graft modification of cationic monomer and carboxymethylchitosan (CMCTS) to remove combined contaminants. The effects of various factors (pH, flocculant dosage and hydraulic mixing conditions) on the flocculation performance under single and composite pollution conditions were systematically investigated, the optimal chemical oxygen demand (COD) and the chromaticity removal rates in the dye wastewater were 79.9% and 83.9% at wastewater pH 7, the fast stirring rate 300 rpm, the fast stirring time 8 min, and the dosage of CPAM-NCS1 80 mg/L, respectively. The optimal removal rates of Cu (II) obtained by CPAM-NCS1 and CPAM-NCS2 at were 80.3% and 75.2% at 60 mg/L and the wastewater pH 7, respectively. The optimal removal rates of Cu (II) and disperse orange were 85.3% and 89.4%, respectively, in a composite pollutant system in which Cu (II) and disperse orange coexisted when the pH of the composite system was 9 and the dosage of CPAM -NCS1 was 60 mg/L. This study proved that nanoflocculants made by modifying CMCTS with different structures can demonstrate ideal flocculation removal performance for dye and heavy metal wastewaters.


Assuntos
Metais Pesados , Águas Residuárias , Cátions , Corantes , Floculação
17.
J Environ Manage ; 299: 113619, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34467865

RESUMO

By virtue of screening, purification, and properties characterization, this study captures a new pH- and temperature-stable laccase, designated Galacc-F, from Ganoderma australe for dye bioremediating applications. The enzyme was purified to homogeneity by salt precipitation, ionic exchange, and size exclusion chromatography with a final specific activity of 22.214 U mg-1, yielding a purification fold of 23.989 and recovery of 38.44%. Its molecular weight was estimated to be 48.0 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, zymography, Sephadex G-100 column, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, which confirmed its monomeric nature. Galacc-F exhibited high levels of activity and stability over wide ranges of pH (5.0-8.0) and temperature (10-60 °C), which are highly valuable properties in industrial processes. Broad substrate specificity was observed, wherein a better affinity was found for 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) with a low value of Km (164.137 µM) and higher kcat/Km ratio (1.663 s-1 µM-1). Activity was stimulated by Cu2+ and ß-mercaptoethanol but inhibited by ethylenediaminetetraacetic acid, diethylpyrocarbonate, iodoacetic acid, phenylmethylsulfonyl fluoride, and Hg2+, indicating that Galacc-F is a metalloprotease containing a typical histidine-cysteine-serine catalytic triad. It had high tolerance to surfactants, oxidants, and salts. Additionally, a fabricated protocol for native Galacc-F immobilization onto Fe3O4@Chitosan composite nanoparticles using glutaraldehyde as a crosslinker was developed. Most importantly, the enzyme was determined to be ideal for use in efficient treatment of dye effluents as compared with the laccases requiring redox mediators.


Assuntos
Ganoderma , Lacase , Biodegradação Ambiental , Corantes , Estabilidade Enzimática , Ganoderma/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Lacase/metabolismo , Temperatura , Têxteis
18.
An Acad Bras Cienc ; 93(4): e20191581, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34586315

RESUMO

Environmental pollution may be considered one of the main problems affecting the world population. As the effluents from textile industries are the largest representatives of sources of pollution of water bodies due to the disposal of colored compounds in the environment. Microorganisms capable of thriving in textile wastewater may exhibit metabolic machinery to synthesize a wide variety of enzymes and/or secondary metabolites of industrial interest. The present work investigated the biotechnological potential of filamentous fungi from wastewater of a textile industry for the production of laccase, cellulase, amylase and lipase enzymes and their potential for discoloration capacity of Remazol Brilliant Blue R synthetic dye. The isolate Aspergillus sydowii (ITF 30) presented the best cellulase (46.74 U mL-1), amylase, lipase and laccase (0.0273 U L-1) production, as well as RBBR dye discoloration ability in solid medium, followed by isolate Aspergillus sydowii (ITF 27) able to synthesize cellulase, amylase and laccase and had the capacity to discolor 74.7% of RBBR in liquid medium. The results of the present work encourage future studies of characterization, optimization and purification of the enzymes encountered, aiming to be used in bioremediation processes of textile industrial effluents.


Assuntos
Corantes , Lacase , Aspergillus , Indústria Têxtil , Têxteis
19.
Water Res ; 204: 117614, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34492363

RESUMO

Fluorescence spectroscopy has become a fundamental tool for the qualitative and quantitative fingerprinting of dissolved organic matter. Due to the inherent sensitivity of the technique, a strict sampling protocol should be followed to ensure sample integrity. A literature survey conducted as part of this research determined that 27% of fluorescence sampling has been conducted in polymeric containers, while 52% did not report. Given the potential for fluorescence leachates to arise from plastics commonly used in sampling bottles, a systematic laboratory investigation was undertaken to assess the likelihood of leachate contamination and consequent interferences. It was observed that characteristic fluorescent dissolved organic matter (FDOM) leachates from standard polypropylene sampling containers were produced at environmentally relevant peaks, Peak T (λEx/λEm: 250/349 nm) and B (λEx/λEm: 250/306 nm), commonly attributed to tryptophan-like and tyrosine-like molecular origins. Leachate fluorescence and concentration generally increased with elevated storage temperatures (>4 °C), sample acidification, container steam sterilisation and in new containers, with variability across different manufactured batches. For example, at ambient storage temperatures, the highest observed leachate intensity could contribute an error equivalent to as much as 98% (Peak T) and 2062% (Peak B) for highly treated water or 28% (Peak T) and 398% (Peak B) for surface water. For leachates formed under typical conditions, i.e., 3-day fridge storage, this reduced to 9% (Peak T) and 15% (Peak B) or 3% (Peak T/B) for the same water samples. In addition, PP was found to be typically unsuitable for DOC measurements, except under strict conditions (well-aged containers in short term cold storage). Consequently, we demonstrate the need for container material reporting, refrigerated storage, steam sterilisation avoidance, and the importance of glass usage for low FDOM samples. Future research should investigate the potential for polymer-based pollution as a potential origin of environmentally sampled FDOM.


Assuntos
Polímeros , Poluentes Químicos da Água , Corantes , Plásticos , Espectrometria de Fluorescência , Poluentes Químicos da Água/análise
20.
J Environ Manage ; 300: 113707, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34534759

RESUMO

Selective removal of contaminants from water by membranes is of practical importance for water purification and environmental protection. In the present study, through an in-situ polymerization process, a novel composite of Fe3O4/molecularly imprinted resorcinol -formaldehyde-melamine resin (Fe3O4/MIRFMR) was synthesized. Then, the novel membrane was prepared from a tea filter bag (TFB) as a base substrate which was subsequently coated by a casting solution containing polyvinylidene fluoride (PVDF) matrix, Prunus scoparia gum as a hydrophilic agent and Fe3O4/MIRFMR as selective filler by phase inversion technique. Resorcinol as functional monomers with multiple hydrophilic groups such as -OH, -NH2 and -NH-, were used for selective removal of Rhodamine B (RhB) as target molecule. The Fe3O4/MIRFMR/PVDF/TFB membranes were characterized by FE-SEM, XRD, FTIR, BET, VSM, water contact angle (WCA) and mechanical analysis. The filtration and adsorption of RhB on the prepared membrane was investigated parameters in a cross-module filtration setup. Casting solution containing 0.01 g of Fe3O4/MIRFMR as optimum value showed good wettability, high water flux (42.5 L/m2 h), flux recovery ratio (88.9%), RhB removal efficiency (95.8%). The selectivity of 4.9, 3.3, 2.1 and 2.5 was found to be for RhB compared to AB, MG, EB, and TB dye. It seems that the fabricated membrane could be an effective and selective option for wastewater containing pollutants. The high removal efficiency, fouling resistance, good wettability and stability of the fabricated membrane are promising for use in practical water filtration, especially for selective removal of dyes.


Assuntos
Corantes , Membranas Artificiais , Fenômenos Magnéticos , Polivinil
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