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1.
Int J Mol Sci ; 25(12)2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38928461

RESUMEN

"Core/shell" composites are based on a ferrite core coated by two layers with different properties, one of them is an isolator, SiO2, and the other is a semiconductor, TiO2. These composites are attracting interest because of their structure, photocatalytic activity, and magnetic properties. Nanocomposites of the "core/shell" МFe2O4/SiO2/TiO2 (М = Zn(II), Co(II)) type are synthesized with a core of MFe2O4 produced by two different methods, namely the sol-gel method (SG) using propylene oxide as a gelling agent and the hydrothermal method (HT). SiO2 and TiO2 layer coating is performed by means of tetraethylorthosilicate, TEOS, Ti(IV) tetrabutoxide, and Ti(OBu)4, respectively. A combination of different experimental techniques is required to prove the structure and phase composition, such as XRD, UV-Vis, TEM with EDS, photoluminescence, and XPS. By Rietveld analysis of the XRD data unit cell parameters, the crystallite size and weight fraction of the polymorphs anatase and rutile of the shell TiO2 and of the ferrite core are determined. The magnetic properties of the samples, and their activity for the photodegradation of the synthetic industrial dyes Malachite Green and Rhodamine B are measured in model water solutions under UV light irradiation and simulated solar irradiation. The influence of the water matrix on the photocatalytic activity is determined using artificial seawater in addition to ultrapure water. The rate constants of the photocatalytic process are obtained along with the reaction mechanism, established using radical scavengers where the role of the radicals is elucidated.


Asunto(s)
Nanocompuestos , Rodaminas , Colorantes de Rosanilina , Titanio , Contaminantes Químicos del Agua , Nanocompuestos/química , Colorantes de Rosanilina/química , Catálisis , Contaminantes Químicos del Agua/química , Rodaminas/química , Titanio/química , Fotólisis , Dióxido de Silicio/química , Compuestos Férricos/química , Procesos Fotoquímicos , Difracción de Rayos X
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 320: 124655, 2024 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-38885572

RESUMEN

Rapid and quantitative detection of malachite green (MG) in aquaculture products is very important for safety assurance in food supply. Here, we develop a point-of-care testing (POCT) platform that combines a flexible and transparent surface-enhanced Raman scattering (SERS) substrate with deep learning network for achieving rapid and quantitative detection of MG in fish. The flexible and transparent SERS substrate was prepared by depositing silver (Ag) film on the polydimethylsiloxane (PDMS) film using laser molecular beam epitaxy (LMBE) technique. The wrinkled Ag NPs@PDMS film exhibits high SERS activity, excellent reproducibility and good mechanical stability. Additionally, the fast in situ detection of MG residues onfishscales was achieved by using the wrinkled Ag NPs/PDMS film and a portable Raman spectrometer, with a minimum detectable concentration of 10-6 M. Subsequently, a one-dimensional convolutional neural network (1D CNN) model was constructed for rapid quantification of MG concentration. The results demonstrated that the 1D CNN quantitative analysis model possessed superior predictive performance, with a coefficient of determination (R2) of 0.9947 and a mean squared error (MSE) of 0.0104. The proposed POCT platform, integrating a transparent flexible SERS substrate, a portable Raman spectrometer and a 1D CNN model, provides an efficient strategy for rapid identification and quantitative analysis of MG in fish.


Asunto(s)
Peces , Redes Neurales de la Computación , Colorantes de Rosanilina , Plata , Espectrometría Raman , Colorantes de Rosanilina/análisis , Colorantes de Rosanilina/química , Espectrometría Raman/métodos , Animales , Plata/química , Plata/análisis , Nanopartículas del Metal/química , Contaminación de Alimentos/análisis , Límite de Detección
3.
J Hazard Mater ; 474: 134742, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-38810577

RESUMEN

Developing a multifunctional material that can detect and remove carcinogens in water environments, simultaneously monitor their toxic metabolites in living organisms is significant for environmental remediation and human health. However, most research only focused on detection or adsorption carcinogens due to the difficulty of integrating multiple functions into one material, let alone monitoring their toxic metabolites. Here, a multifunctional Tb/Eu@TATB-HOF (1) is first developed to monitor two carcinogens, malachite green (MG) and its metabolites leucomalachite green (LMG), and simultaneously remove MG from the contaminated water. 1, as the dual-emission fluorescence sensor, can achieve ultrasensitive and highly visualized sensing for MG and LMG with different response modes. Even in actual samples, 1 still exhibits satisfactory sensing performances. As the adsorbent, 1 displays good recyclability and high adsorption capacity for MG. The sensing and adsorption mechanisms are explored through experiments and theoretical calculations. This work not only provides a novel insight for environmental remediation and human health through detection and removal of carcinogens, simultaneously monitoring their toxic metabolites, but first reveals the enormous potential of HOFs as multifunctional materials simultaneously for fluorescence sensing and adsorption.


Asunto(s)
Carcinógenos , Colorantes de Rosanilina , Contaminantes Químicos del Agua , Adsorción , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/química , Carcinógenos/análisis , Colorantes de Rosanilina/química , Colorantes de Rosanilina/análisis , Purificación del Agua/métodos , Colorantes Fluorescentes/química
4.
Zhongguo Zhong Yao Za Zhi ; 49(7): 1818-1825, 2024 Apr.
Artículo en Chino | MEDLINE | ID: mdl-38812194

RESUMEN

A label-free fluorescence method based on malachite green/aptamer was developed for the detection of ochratoxin A(OTA) in traditional Chinese medicines. Malachite green itself exhibits weak fluorescence. Upon interaction with the aptamer specific to OTA, the G-quadruplex structure of the aptamer provides a protective microenvironment for malachite green, which significantly enhances its fluorescence signal. After OTA is added, preferential binding occurs between the aptamer and OTA, and malachite green will be released from the aptamer, which weakens the fluorescence signal. According to this principle, this paper established a fluorescence method with the aptamer of OTA as the recognition element and malachite green as the fluorescent probe for the detection of OTA in traditional Chinese medicines. The key experimental factors such as the concentrations of metal ions, aptamer, and malachite green were optimized to improve the performance of the method. OTA was detected under the optimal experimental conditions, and the results showed that with the increase in OTA concentration, the fluorescence signal gradually weakened. Within the range of 20-1 000 nmol·L~(-1), the OTA concentration was linearly correlated with the fluorescence signal ratio ΔF/F(ΔF=F_0-F, where F_0 is the fluorescence signal of aptamer/malachite green, and F is the fluorescence signal of OTA/aptamer/malachite green), with R~2 of 0.995. The limit of detection of the established method was 7.1 nmol·L~(-1). Furthermore, three substances structurally similar to OTA and two mycotoxins that may coexist with OTA were selected for experiments, which aimed to examine the cross-reactivity and specificity of the established method. The cross-reactivity experiments demonstrated that the interferers did not significantly affect the fluorescence signal of the detection system. The specificity experiments revealed that when mycotoxins were mixed with OTA, the fluorescence signal generated by the mixture closely resembled that of OTA itself. The results indicated that even in the presence of interferents, the established method remained unaffected and demonstrated excellent specificity. Additionally, this method exhibited remarkable reproducibility and stability. In the case of simple centrifugation and dilution of traditional Chinese medicine samples(Puerariae Lobatae Radix, Sophorae Flavescentis Radix, and Periplocae Cortex), the OTA detection method was applicable, with recovery rates ranging from 91.5% to 121.3%. Notably, this approach does not need complex pretreatment of traditional Chinese medicines while offering simple operation, low detection costs, and short detection time. Furthermore, by incorporating aptamers into the quality evaluation of traditional Chinese medicines, this method expands the application scope of aptamers.


Asunto(s)
Aptámeros de Nucleótidos , Medicamentos Herbarios Chinos , Ocratoxinas , Colorantes de Rosanilina , Colorantes de Rosanilina/química , Colorantes de Rosanilina/análisis , Ocratoxinas/análisis , Ocratoxinas/química , Aptámeros de Nucleótidos/química , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/análisis , Espectrometría de Fluorescencia/métodos , Contaminación de Medicamentos/prevención & control , Fluorescencia , Medicina Tradicional China
5.
Chemosphere ; 360: 142376, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38777197

RESUMEN

Currently, adsorbents with high adsorption performance for eliminating pollutants from discharged wastewater have received many researchers' attention. To this aim, a novel AMXGO absorbent was fabricated by intercalating graphene oxide (GO) into alkalized MXene (Alk-MXene) layer which exhibited high efficacy for the removal of cationic Malachite Green (MG) and anionic Congo Red (CR). Analysis of FTIR, XRD, SEM and TG presented that AMXGO absorbent have a typical three-dimensional layer by layer structure and abundant oxygen-containing groups and its thermal stability was remarkably improved. BET results elucidated that AMXGO1 adsorbent has larger specific surface area and pore volume (16.686 m2 g-1, 0.04733 cm3 g-1) as compared to Alk-MXene (4.729 m2 g-1, 0.02522 cm3 g-1). A dependence of adsorption performance on mass ratio between Alk-MXene and GO, initial dye concentration, contact time, temperature and pH was revealed. Maximum adsorption capacity of MG (1111.6 mg/g) and CR (1133.7 mg/g) were particularly found for AMXGO1 absorbent with a mass ratio of 3:1 and its removal for both dyes were higher than 92%. The adsorption process of AMXGO1 adsorbent for both MG and CR complies with pseudo-second-order kinetic model and Freundlich isotherm model. In addition, adsorption mechanism was explored that synergism effects as electrostatic attraction, π-π conjugates, intercalation adsorption and pore filling were the main driving force for the high adsorption performance of dye. Therefore, AMXGO adsorbent has a potential application prospect in the purification of dye wastewater.


Asunto(s)
Rojo Congo , Grafito , Colorantes de Rosanilina , Aguas Residuales , Contaminantes Químicos del Agua , Grafito/química , Adsorción , Contaminantes Químicos del Agua/química , Colorantes de Rosanilina/química , Colorantes de Rosanilina/aislamiento & purificación , Rojo Congo/química , Aguas Residuales/química , Purificación del Agua/métodos , Cinética , Colorantes/química , Colorantes/aislamiento & purificación , Concentración de Iones de Hidrógeno
6.
Environ Res ; 252(Pt 3): 119046, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38704004

RESUMEN

Reports have shown that malachite green (MG) dye causes various hormonal disruptions and health hazards, hence, its removal from water has become a top priority. In this work, zinc oxide decorated plantain peels activated carbon (ZnO@PPAC) was developed via a hydrothermal approach. Physicochemical characterization of the ZnO@PPAC nanocomposite with a 205.2 m2/g surface area, porosity of 614.68 and dominance of acidic sites from Boehm study established the potency of ZnO@PPAC. Spectroscopic characterization of ZnO@PPAC vis-a-viz thermal gravimetric analyses (TGA), Fourier Transform Infrared Spectroscopy (FTIR), Powdered X-ray Diffraction (PXRD), Scanning Electron Microscopy and High Resolution - Transmission Electron Microscopy (HR-TEM) depict the thermal stability via phase transition, functional group, crystallinity with interspatial spacing, morphology and spherical and nano-rod-like shape of the ZnO@PPAC heterostructure with electron mapping respectively. Adsorption of malachite green dye onto ZnO@PPAC nanocomposite was influenced by different operational parameters. Equilibrium data across the three temperatures (303, 313, and 323 K) were most favorably described by Freundlich indicating the ZnO@PPAC heterogeneous nature. 77.517 mg/g monolayer capacity of ZnO@PPAC was superior to other adsorbents compared. Pore-diffusion predominated in the mechanism and kinetic data best fit the pseudo-second-order. Thermodynamics studies showed the feasible, endothermic, and spontaneous nature of the sequestration. The ZnO@PPAC was therefore shown to be a sustainable and efficient material for MG dye uptake and hereby endorsed for the treatment of industrial effluent.


Asunto(s)
Carbón Orgánico , Colorantes de Rosanilina , Termodinámica , Contaminantes Químicos del Agua , Óxido de Zinc , Colorantes de Rosanilina/química , Óxido de Zinc/química , Adsorción , Cinética , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/análisis , Carbón Orgánico/química , Colorantes/química
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 318: 124447, 2024 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-38761471

RESUMEN

Label-free nucleic acid fluorescent probes are gaining popularity due to their low cost and ease of application. However, the primary challenges associated with label-free fluorescent probes stem from their tendency to interact with other biomolecules, such as RNA, proteins, and enzymes, which results in low specificity. In this work, we have developed a simple detection platform that utilizes Fe3O4@PPy in combination with a label-free nucleic acid probe, 1,1,2,2-tetrakis[4-(2-bromo-ethoxy)phenyl]ethene (TTAPE) or Malachite Green (MG), for highly selective detection of metal ions, acetamiprid, and thrombin. Fe3O4@PPy not only adsorbs aptamers through electrostatic interactions, π-π bonding, and hydrogen bonding, but also quenches the fluorescence of the TTAPE/MG. Upon the addition of target compounds, the aptasensor separates from Fe3O4@PPy through magnetic separation. Moreover, by changing different aptamers, the aptasensor was applied to detect metal ions, acetamiprid, and thrombin, with the turned-on photoluminescence (PL) emission intensity recorded and showing linearity to the concentrations of targets. The robustness of method was demonstrated by applying it to real samples, which included vegetables (for detecting acetamiprid with LODs of 0.02 and 0.04 ng/L), serum samples (for detecting thrombin with LODs of 5.5 and 4.3 nM), and water samples (for detecting Pb2+ with an LOD of 0.17 nM). Therefore, due to its impressive selectivity and sensitivity, the Fe3O4@PPy aptasensor could be utilized as a universal detection platform for various clinical and environmental applications.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Colorantes Fluorescentes , Neonicotinoides , Espectrometría de Fluorescencia , Trombina , Aptámeros de Nucleótidos/química , Trombina/análisis , Colorantes Fluorescentes/química , Técnicas Biosensibles/métodos , Neonicotinoides/análisis , Espectrometría de Fluorescencia/métodos , Límite de Detección , Colorantes de Rosanilina/análisis , Colorantes de Rosanilina/química , Humanos , Polímeros/química
8.
Food Chem ; 452: 139543, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38735107

RESUMEN

Malachite green (MG), a widely used antiparasitic agent, poses health risks to human due to its genotoxic and carcinogenic properties. Herein, a stable dual-emission fluoroprobe of carbon dots/copper nanoclusters is prepared for highly selective detection of MG based on the inner filter effect. This probe exhibits characteristic emission bands at 435 and 625 nm when excited at 376 nm. After adding MG, the both emission signals were significantly quenched, and the ratio of fluorescence intensity (F435/F625) was linearly related to the concentration of MG in the range of 0.05-40 µmol L-1 with a limit of detection of 18.2 nmol L-1. Meanwhile, the two signals exhibit linear relationships with the concentration of MG, respectively, and the corresponding detection results were consistent. The fluoroprobe was successfully used for the detection of MG in fish samples with the recoveries ranging from 96.0% to 103.8% and a relative standard deviation of <3.3%.


Asunto(s)
Carbono , Cobre , Peces , Nanocompuestos , Puntos Cuánticos , Colorantes de Rosanilina , Colorantes de Rosanilina/química , Colorantes de Rosanilina/análisis , Cobre/química , Cobre/análisis , Animales , Puntos Cuánticos/química , Carbono/química , Nanocompuestos/química , Espectrometría de Fluorescencia/métodos , Contaminación de Alimentos/análisis , Límite de Detección , Fluorescencia , Colorantes Fluorescentes/química
9.
Anal Biochem ; 691: 115553, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38697592

RESUMEN

We describe a microwave-assisted, methanol and acetic acid-free, inexpensive method for rapid staining of SDS-PAGE proteins. Only citric acid, benzoic acid, and Coomassie brilliant blue G-250 (CBG) were used. Microwave irradiation reduced the detection duration, and proteins in a clear background were visualized within 30 min of destaining, after 2 min of fixing and 12 min of staining. By using this protocol, comparable band intensities were obtained to the conventional methanol/acetic acid method.


Asunto(s)
Ácido Acético , Electroforesis en Gel de Poliacrilamida , Metanol , Microondas , Proteínas , Electroforesis en Gel de Poliacrilamida/métodos , Metanol/química , Proteínas/análisis , Ácido Acético/química , Coloración y Etiquetado/métodos , Colorantes de Rosanilina/química
10.
Food Chem ; 451: 139454, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38703725

RESUMEN

Morphology regulation of heterodimer nanoparticles and the use of their asymmetric features for further practical applications are crucial because of the rich optical properties and various combinations of heterodimers. This work used silicon to asymmetrically wrap half of a gold sphere and grew gold branches on the bare gold surface to form heterogeneous nano pineapples (NPPs) which can effectively improve Surface-enhanced Raman scattering (SERS) properties through chemical enhancement and lightning-rod effect respectively. The asymmetric structures of NPPs enabled them to self-assemble into the monolayer membrane with consistent branch orientation. The prepared substrate had high homogeneity and better SERS ability than disorganized substrates, and achieved reliable detection of malachite green (MG) in clams with a detection limit of 7.8 × 10-11 M. This work provided a guide to further revise the morphology of heterodimers and a new idea for the use of asymmetric dimers for practically photochemical and biomedical sensing.


Asunto(s)
Oro , Colorantes de Rosanilina , Silicio , Espectrometría Raman , Colorantes de Rosanilina/química , Espectrometría Raman/métodos , Oro/química , Silicio/química , Animales , Ananas/química , Nanopartículas del Metal/química , Bivalvos/química , Límite de Detección , Propiedades de Superficie
11.
Talanta ; 274: 126039, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38604043

RESUMEN

The development of intelligent, sensitive, and visual methods for the rapid detection of veterinary drug residues is essential to ensure food quality and safety. Here, a smartphone-based dual inverse signal MOFs fluorescence sensing system was proposed for intelligent in-site visual detection of malachite green (MG). A UiO-66-NH2@RhB-dual-emission fluorescent probe was successfully synthesized in one step using a simple one-pot method. The inner filter effect (IFE) quenches the red fluorescence, while hydrogen bonding interaction enhances the blue fluorescence, enabling highly sensitive, accurate, and visual detection of MG dual inverse signals through fluorescence analysis. The probe showed great linearity over a wide range of 0.1-100 µmol/L, with a limit of detection (LOD) of 20 nmol/L. By integrating smartphone photography and RGB (red, green, and blue) analysis, accurate quantitative analysis of MG in water and actual fish samples can be achieved within 5 min. This developed platform holds great promise for the on-site detection of MG in practical applications, with the advantages of simplicity, cost-effectiveness, and rapidity. Consequently, it may open up a new pathway for on-site evaluation of food safety and environmental health.


Asunto(s)
Colorantes Fluorescentes , Colorantes de Rosanilina , Teléfono Inteligente , Colorantes de Rosanilina/análisis , Colorantes de Rosanilina/química , Colorantes Fluorescentes/química , Espectrometría de Fluorescencia/métodos , Animales , Límite de Detección , Fluorescencia , Peces , Contaminantes Químicos del Agua/análisis
12.
Food Chem ; 451: 139399, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38663240

RESUMEN

Malachite green (MG) has been illicitly employed in aquaculture as a parasiticide, however, its teratogenic and carcinogenic effects pose a significant human health threat. Herein, a dual-mode colorimetric and electrochemical aptasensor was fabricated for MG detection, capitalizing on the robust catalytic and peroxidase-like activity of P-CeO2NR@Mxene and good capture efficiency of a tetrahedral DNA nanostructure (TDN) designed with multiple aptamers (m-TDN). P-CeO2NR@Mxene-modified complementary DNA (cDNA) served as both colorimetric and electrochemical probe. m-TDN was attached to AuE to capture MG and P-CeO2NR@Mxene/cDNA. The superior aptamer and MG binding to cDNA regulated signals and enabled precise MG quantification. The further introduced Exo I enabled aptamer hydrolysis, releasing MG for further binding rounds, allowing target recycling amplification. Under the optimal conditions, the aptasensor reached an impressively low detection limit 95.4 pM in colorimetric mode and 83.6 fM in electrochemical mode. We believe this dual-mode approach holds promise for veterinary drug residue detection.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Colorimetría , Técnicas Electroquímicas , Colorantes de Rosanilina , Aptámeros de Nucleótidos/química , Colorantes de Rosanilina/química , Colorantes de Rosanilina/análisis , Técnicas Biosensibles/instrumentación , Exodesoxirribonucleasas/química , Exodesoxirribonucleasas/metabolismo , Límite de Detección , Contaminación de Alimentos/análisis
13.
Int J Phytoremediation ; 26(9): 1453-1464, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38505937

RESUMEN

The improvement of biosorption efficiency for selective dye removal in a multi-dye aqueous system has become an increasingly significant research topic. However, the competitive effects of coexisting dyes and the target dye in such systems remain uncertain due to complex interactions between adsorbent and coexisting dyes. Therefore, in this research, response surface methodology (RSM) model was effectively employed to investigate the competitive effects of allura red (AR) and malachite green (MG) on methylene blue (MB) removal in a ternary dye aqueous system using three different parts of rape straw powders. In the current design of RSM, the initial concentrations of AR and MG dyes ranging from 0 mg·L-1 to 500 mg·L-1 were considered as influencing factors, while the removal rates of MB on adsorbents at an initial concentration of 500 mg·L-1 were established as response values. The RSM models exhibited high correlation coefficients with adjusted R2 values of 0.9908 (pith core), 0.9870 (seedpods), and 0.9902 (shells), respectively, indicating a close fitted between predicted and actual values. The proposed models indicated that the perturbation effects of initial AR and MG concentrations were observed on the removal rates of MB by three types of rape straw powders in a ternary dye aqueous system, resulting in a decrease in MB removal rates, particularly at higher initial AR concentration due to stronger competitive effects compared to initial MG concentration. The structures of rape straw powders, including pith core, seedpods and shell, were analyzed using scanning eletron microscoe (SEM), energy dispersive spectroscopy (EDS), N2 physisorption isotherm, frourier transform infared spectroscopy (FTIR), Zeta potential classes and fluorescence spectrum before and after adsorption of MB in various dye aqueous systems. The characteristics of rape straw powders suggested that similar adsorption mechanisms, such as electrostatic attraction, pore diffusion, and group complex formation for MB, AR, and MG, respectively, occurred on the surfaces of adsorbents during their respective adsorption processes. This leads to significant competitive effects on the removal rates of MB in a ternary dye aqueous system, which are particularly influenced by initial AR concentrations as confirmed through fluorescence spectrum analysis.


Impact of AR and MG on MB removal was analyzed using simple methodologies.Competitive behaviors between AR, MG and MB were understood through RSM.Intense restrain effects on MB removal were revealed by AR concentration.


Asunto(s)
Biodegradación Ambiental , Colorantes , Azul de Metileno , Polvos , Contaminantes Químicos del Agua , Adsorción , Colorantes/química , Colorantes de Rosanilina/química , Brassica rapa , Compuestos Azo , Eliminación de Residuos Líquidos/métodos
14.
Chemosphere ; 355: 141696, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38499077

RESUMEN

The present study investigated the removal of malachite green dye from aquifers by means of microalgae-derived mesoporous diatom biosilica. The various process variables (dye concentration, pH, and adsorbent dose) influencing the removal of the dye were optimized and their interactive effects on the removal efficiency were explored by response surface methodology. The pH of the solution (pH = 5.26) was found to be the most dominating among other tested variables. The Langmuir isotherm (R2 = 0.995) best fitted the equilibrium adsorption data with an adsorption capacity of 40.7 mg/g at 323 K and pseudo-second-order model (R2 = 0.983) best elucidated the rate of dye removal (10.6 mg/g). The underlying mechanism of adsorption was investigated by Weber-Morris and Boyd models and results revealed that the film diffusion governed the overall adsorption process. The theoretical investigations on the dye structure using DFT-based chemical reactivity descriptors indicated that malachite green cations are electrophilic, reactive and possess the ability to accept electrons, and are strongly adsorbed on the surface of diatom biosilica. Also, the Fukui function analysis proposed the favorable adsorption sites available on the adsorbent surface.


Asunto(s)
Diatomeas , Microalgas , Contaminantes Químicos del Agua , Adsorción , Cinética , Colorantes de Rosanilina/química , Concentración de Iones de Hidrógeno , Contaminantes Químicos del Agua/química , Termodinámica
15.
Environ Sci Pollut Res Int ; 31(18): 26806-26823, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38453761

RESUMEN

Toxic organic dyes-containing wastewater treatment by adsorption and photocatalytic techniques is widely applied, but adsorbents and photocatalysts are often synthesized through chemical methods, leading to secondary pollution by released chemicals. Here, we report a benign method using Tecoma stans floral extract to produce MgFe2O4/ZnO (MGFOZ) nanoparticles for adsorption and photocatalytic degradation of coomassie brilliant blue (CBB) dye. Green MGFOZ owned a surface area of 9.65 m2/g and an average grain size of 54 nm. This bio-based nanomaterial showed higher removal percentage and better recyclability (up to five cycles) than green MgFe2O4 and ZnO nanoparticles. CBB adsorption by MGFOZ was examined by kinetic and isotherm models with better fittings of Bangham and Langmuir or Temkin. RSM-based optimization was conducted to reach an actual adsorption capacity of 147.68 mg/g. Moreover, MGFOZ/visible light system showed a degradation efficiency of 89% CBB dye after 120 min. CBB adsorption can be controlled by both physisorption and chemisorption while •O2- and •OH radicals are responsible for photo-degradation of CBB dye. This study suggested that MGFOZ can be a promising adsorbent and catalyst for removal of organic dyes in water.


Asunto(s)
Colorantes de Rosanilina , Contaminantes Químicos del Agua , Óxido de Zinc , Adsorción , Colorantes de Rosanilina/química , Óxido de Zinc/química , Contaminantes Químicos del Agua/química , Catálisis , Nanopartículas/química , Extractos Vegetales/química , Colorantes/química , Flores/química , Compuestos Férricos/química
16.
Environ Res ; 251(Pt 1): 118647, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38460666

RESUMEN

In this work, the self-assembled SrTiO3 (STO) microstructures were synthesized via a facile one-step solvothermal method. As the solvothermal temperature increased from 140 °C to 200 °C, the STO changed from a flower-like architecture to finally an irregularly aggregated flake-like morphology. The photocatalytic performance of as-synthesized samples was assessed through the degradation of rhodamine B (RhB) and malachite green (MG) under simulated solar irradiation. The results indicated that the photocatalytic performance of STO samples depended on their morphology, in which the hierarchical flower-like STO synthesized at 160 °C demonstrated the highest photoactivities. The photocatalytic enhancement of STO-160 was benefited from its large surface area and mesoporous configuration, hence facilitating the presence of more reactive species and accelerating the charge separation. Moreover, the real-world practicality of STO-160 photocatalysis was examined via the real printed ink wastewater-containing RhB and MG treatment. The phytotoxicity analyses demonstrated that the photocatalytically treated wastewater increased the germination of mung bean seeds, and the good reusability of synthesized STO-160 in photodegradation reaction also promoted its application in practical scenarios. This work highlights the promising potential of tailored STO microstructures for effective environmental remediation applications.


Asunto(s)
Óxidos , Fotólisis , Estroncio , Titanio , Contaminantes Químicos del Agua , Titanio/química , Contaminantes Químicos del Agua/química , Óxidos/química , Estroncio/química , Catálisis , Colorantes de Rosanilina/química , Rodaminas/química , Colorantes/química , Luz Solar , Aguas Residuales/química , Eliminación de Residuos Líquidos/métodos
17.
Environ Res ; 250: 118510, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38387495

RESUMEN

The literature rarely compiles studies devoted to the removal of pollutants in aqueous media comparing adsorption and photocatalytic degradation, and does not pay enough attention to the analysis of combined adsorption-photocatalytic oxidation processes. In the present manuscript, the removal of malachite green (MG) from aqueous solutions has been investigated in three different sustainable scenarios: i) adsorption on activated carbon (AC) derived from a residue, luffa cylindrica, ii) photocatalytic oxidation under simulated solar light using titanium dioxide (TP) and iii) combined adsorption-photocatalytic oxidation using TP-AC (70/30 wt./wt.) under simulated solar light. The study has revealed that in the three scenarios and studied conditions, the total removal of this endocrine-disrupting dye from the solution takes place in the assayed time, 2 h, in some cases just in a few minutes. MG adsorption in the AC is a very fast and efficient removal method. MG photocatalytic oxidation with TP also occurs efficiently, although the oxidized MG is not totally mineralized. MG removal using the TP-AC composite under simulated solar light occurs only slightly faster to the MG adsorption in the AC, being adsorption the dominating MG removal mechanism for TP-AC. Thus, more than 90% of the removed MG with TP-AC under simulated solar light is adsorbed in this carbon-containing composite. The obtained results highlight the interest in adsorption, being the selection of the most suitable removal method dependent on several factors (i.e., the cost of the AC regeneration, for adsorption, or the toxicity of the intermediate oxidation species, for photooxidation). Paying attention to MG photooxidation with TiO2, comparison of two working photodegradation schemes shows that the direct photodegradation of MG from solution, avoiding any initial dark equilibrium period, is more efficient from a time perspective. The use of scavengers has proved that MG photodegradation occurs via an oxidation mechanism dominated by superoxide anion radicals.


Asunto(s)
Oxidación-Reducción , Colorantes de Rosanilina , Titanio , Contaminantes Químicos del Agua , Colorantes de Rosanilina/química , Titanio/química , Adsorción , Contaminantes Químicos del Agua/química , Catálisis , Carbón Orgánico/química , Purificación del Agua/métodos , Fotólisis , Procesos Fotoquímicos
18.
Nucleic Acids Res ; 52(7): e36, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38407347

RESUMEN

Cellular RNA is asymmetrically distributed in cells and the regulation of RNA localization is crucial for proper cellular functions. However, limited chemical tools are available to capture dynamic RNA localization in complex biological systems with high spatiotemporal resolution. Here, we developed a new method for RNA proximity labeling activated by near-infrared (NIR) light, which holds the potential for deep penetration. Our method, termed FAP-seq, utilizes a genetically encoded fluorogen activating protein (FAP) that selectively binds to a set of substrates known as malachite green (MG). FAP binding restricts the rotation of MG and rapidly activates its fluorescence in a wash-free manner. By introducing a monoiodo modification to MG, we created a photosensitizer (MG-HI) with the highest singlet oxygen generation ability among various MG derivatives, enabling both protein and RNA proximity labeling in live cells. New insights are provided in the transcriptome analysis with FAP-seq, while a deeper understanding of the symmetry-breaking structural arrangement of FAP-MG-HI was obtained through molecular dynamics simulations. Overall, our wash-free and NIR light-inducible RNA proximity labeling method (FAP-seq) offers a powerful and versatile approach for investigating complex mechanisms underlying RNA-related biological processes.


Asunto(s)
Colorantes Fluorescentes , Rayos Infrarrojos , Fármacos Fotosensibilizantes , ARN , Colorantes de Rosanilina , Colorantes de Rosanilina/química , Fármacos Fotosensibilizantes/química , Humanos , Colorantes Fluorescentes/química , ARN/química , ARN/metabolismo , Oxígeno Singlete/metabolismo , Oxígeno Singlete/química , Simulación de Dinámica Molecular , Células HeLa
19.
Int J Phytoremediation ; 26(8): 1321-1335, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38409765

RESUMEN

This research explores the feasibility of using date seeds (DS), an agricultural waste, for the adsorption of malachite green (MG) dye from synthesized wastewater. The characterization of the DS before and after adsorption was accomplished by FTIR, SEM, BET, and EDX measurements. Batch adsorption experiments were investigated for MG dye adsorption from aqueous solution onto the DS. The effect of different parameters such as solution pH, adsorbent dose, contact time, temperature, and the initial dye concentration were studied. The optimum pH, adsorbent dose, temperature, and contact time for the dye removal were found to be 5, 0.1 g, 25 °C, and 30 min, respectively. The equilibrium studies for the data with Langmuir, Freundlich, and Temkin isotherms showed that Freundlich isotherm is the best model to describe the adsorption of MG onto the DS particles which has a heterogeneous surface. It was found that the adsorption process follows a pseudo-second-order kinetic model which revealed that the intra-particle diffusion stage is the rate-controlling stage for the process. The thermodynamic parameters ΔG, ΔS, and ΔH suggest the possibility of chemisorption and physisorption simultaneously and indicate the exothermic and spontaneous characters of the adsorption of MG dye on DS with negative values of ΔH and ΔG.


This study used agriculture waste (date seeds) which is proved to be an environmentally friendly and low-cost adsorbent. The date seeds were shown to be a promising adsorbent, demonstrating high surface area and well-developed porosity. The prepared adsorbent will have a great impact on wastewater treatment technology and possible applications at a large scale. Thus, widespread and great progress in this area can be expected in the future.


Asunto(s)
Colorantes de Rosanilina , Semillas , Termodinámica , Eliminación de Residuos Líquidos , Aguas Residuales , Contaminantes Químicos del Agua , Colorantes de Rosanilina/química , Adsorción , Aguas Residuales/química , Cinética , Semillas/química , Eliminación de Residuos Líquidos/métodos , Biodegradación Ambiental , Colorantes/química
20.
Int J Phytoremediation ; 26(8): 1193-1211, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38226539

RESUMEN

In this work, green method to synthesize chromium-doped zinc oxide (ZnO) nanorods (NRs) using an aqueous flower extract from Rhododendron arboretum is explored. Herein, chromium-doped ZnO NRs were prepared with different amount of chromium doping, varied as 2-10%. The green synthesized products underwent substantial analysis through X-ray diffraction (XRD), spectroscopic such as ultraviolet spectroscopy(UV-Vis) and scanning electron microscopy (SEM) methods. All samples were found to have hexagonal wurtzite ZnO, with average particle sizes of 52.41, 56.6, 54.44, 53.05, and 56.99 nm, respectively, for 2, 4, 6, 8, and 10% chromium doping in ZnO NRs. The Cr-doped ZnO NRs exhibited remarkable photocatalytic degradation activity of cationic dyes under UV-light, i.e., Malachite Green and Fuchsin Basic with degradation of 99.604 and 99.881%, respectively in 90 min. The reusability tests for these green synthesized Cr-doped ZnO NRs have also been carried out, showed 9-11 cycles with 85% of degradation efficiency. In addition, the Cr-doped ZnO NRs exhibited high selectivity for cationic dyes when experiments against mixture of dyes were performed. Photodegradation kinetics followed the pseudo-first-order model. The flower-extract-stabilized chromium-doped ZnO NRs demonstrated high photocatalytic activity toward malachite green and fuchsin basic dyes, potential material for pollution remediation.


Cr-doped ZnO NRs by green method using flower extract of Rhododendon arboretum were prepared for the first time under ambient reaction conditions.Effect of Dopant i.e. Cr on Photocatalytic activity have been exploited.Selective photocatalytic degradation of cationic dyes i.e. MG, and FB has been achieved in 60­90 minutes.Optimization of reaction condition and various parameters has also been carried out.Recyclability of Cr-doped ZnO NRs was also evaluated and were found to be reusable for 11 cycles for degradation.


Asunto(s)
Cromo , Flores , Nanotubos , Extractos Vegetales , Rhododendron , Colorantes de Rosanilina , Óxido de Zinc , Nanotubos/química , Cromo/química , Colorantes de Rosanilina/química , Flores/química , Extractos Vegetales/química , Óxido de Zinc/química , Rhododendron/química , Tecnología Química Verde , Biodegradación Ambiental , Catálisis , Colorantes/química , Fotólisis , Contaminantes Químicos del Agua/química
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