RESUMO
In this study, a hydrothermal process was utilized to grow mixed-valence CuFe2O4/Cu0 nanosheets on carbon fiber paper, forming a three-dimensional hierarchical electrode (CuFe2O4/Cu0@CFP). The ordered array structure, coupled with the porous bowl-like structure, enhances the exposure of more electrode active sites and facilitates analyte penetration, thus enhancing the electrode sensing performance. As a binder-free sensor, the CuFe2O4/Cu0@CFP sensor exhibited remarkable sensitivity in detecting Malachite Green (MG), Sunset Yellow (SY) and Tartrazine (TA) over wide concentration ranges: 0.1-300 µM for MG (R2 = 0.994), 0.005-200 µM for SY (R2 = 0.996), and 0.005-300 µM for TA (R2 = 0.995) with low detection limits of 0.033 µM for MG, 0.0016 µM for SY, and 0.0016 µM for TA (S/N = 3), respectively. Additionally, the 3D CuFe2O4/Cu0@CFP sensor detected MG, SY, and TA in a mixed solution with satisfactory results. It also performs well in beverage, fruit juice powder, and jelly samples, with results matching those from HPLC.
Assuntos
Compostos Azo , Cobre , Nanoestruturas , Corantes de Rosanilina , Tartrazina , Cobre/química , Cobre/análise , Tartrazina/análise , Tartrazina/química , Nanoestruturas/química , Corantes de Rosanilina/química , Corantes de Rosanilina/análise , Compostos Azo/química , Compostos Azo/análise , Fibra de Carbono/química , Contaminação de Alimentos/análise , Técnicas Eletroquímicas/instrumentação , Limite de Detecção , Corantes de Alimentos/análise , Corantes de Alimentos/química , PapelRESUMO
SERS measurements for monitoring bactericides in dairy products are highly desired for food safety problems. However, the complicated preparation process of SERS substrates greatly impedes the promotion of SERS. Here, we propose acoustofluidic one-step synthesis of Ag nanoparticles on paper substrates for SERS detection. Our method is economical, fast, simple, and eco-friendly. We adopted laser cutting to cut out appropriate paper shapes, and aldehydes were simultaneously produced at the cutting edge in the pyrolysis of cellulose by laser which were leveraged as the reducing reagent. In the synthesis, only 5 µL of Ag precursor was added to complete the reaction, and no reducing agent was used. Our recently developed acoustofluidic device was employed to intensely mix Ag+ ions and aldehydes and spread the reduced Ag nanoparticles over the substrate. The SERS substrate was fabricated in 1 step and 3 min. The standard R6G solution measurement demonstrated the excellent signal and prominent uniformity of the fabricated SERS substrates. SERS detection of the safe concentration of three bactericides, including tetracycline hydrochloride, thiabendazole, and malachite green, from food samples can be achieved using fabricated substrates. We take the least cost, time, reagents, and steps to fabricate the SERS substrate with satisfying performance. Our work has an extraodinary meaning for the green preparation and large-scale application of SERS.
Assuntos
Antibacterianos , Nanopartículas Metálicas , Papel , Prata , Análise Espectral Raman , Prata/química , Nanopartículas Metálicas/química , Antibacterianos/análise , Propriedades de Superfície , Tetraciclina/análise , Corantes de Rosanilina/análise , Corantes de Rosanilina/química , Tiabendazol/análise , Tamanho da PartículaRESUMO
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.
Assuntos
Peixes , Redes Neurais de Computação , Corantes de Rosanilina , Prata , Análise Espectral Raman , Corantes de Rosanilina/análise , Corantes de Rosanilina/química , Análise Espectral Raman/métodos , Animais , Prata/química , Prata/análise , Nanopartículas Metálicas/química , Contaminação de Alimentos/análise , Limite de DetecçãoRESUMO
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.
Assuntos
Aptâmeros de Nucleotídeos , Medicamentos de Ervas Chinesas , Ocratoxinas , Corantes de Rosanilina , Corantes de Rosanilina/química , Corantes de Rosanilina/análise , Ocratoxinas/análise , Ocratoxinas/química , Aptâmeros de Nucleotídeos/química , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/análise , Espectrometria de Fluorescência/métodos , Contaminação de Medicamentos/prevenção & controle , Fluorescência , Medicina Tradicional ChinesaRESUMO
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.
Assuntos
Carcinógenos , Corantes de Rosanilina , Poluentes Químicos da Água , Adsorção , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Carcinógenos/análise , Corantes de Rosanilina/química , Corantes de Rosanilina/análise , Purificação da Água/métodos , Corantes Fluorescentes/químicaRESUMO
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%.
Assuntos
Carbono , Cobre , Peixes , Nanocompostos , Pontos Quânticos , Corantes de Rosanilina , Corantes de Rosanilina/química , Corantes de Rosanilina/análise , Cobre/química , Cobre/análise , Animais , Pontos Quânticos/química , Carbono/química , Nanocompostos/química , Espectrometria de Fluorescência/métodos , Contaminação de Alimentos/análise , Limite de Detecção , Fluorescência , Corantes Fluorescentes/químicaRESUMO
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.
Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Corantes Fluorescentes , Neonicotinoides , Espectrometria de Fluorescência , Trombina , Aptâmeros de Nucleotídeos/química , Trombina/análise , Corantes Fluorescentes/química , Técnicas Biossensoriais/métodos , Neonicotinoides/análise , Espectrometria de Fluorescência/métodos , Limite de Detecção , Corantes de Rosanilina/análise , Corantes de Rosanilina/química , Humanos , Polímeros/químicaRESUMO
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.
Assuntos
Corantes Fluorescentes , Corantes de Rosanilina , Smartphone , Corantes de Rosanilina/análise , Corantes de Rosanilina/química , Corantes Fluorescentes/química , Espectrometria de Fluorescência/métodos , Animais , Limite de Detecção , Fluorescência , Peixes , Poluentes Químicos da Água/análiseRESUMO
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.
Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Colorimetria , Técnicas Eletroquímicas , Corantes de Rosanilina , Aptâmeros de Nucleotídeos/química , Corantes de Rosanilina/química , Corantes de Rosanilina/análise , Técnicas Biossensoriais/instrumentação , Exodesoxirribonucleases/química , Exodesoxirribonucleases/metabolismo , Limite de Detecção , Contaminação de Alimentos/análiseRESUMO
Concerns about food safety have been arisen due to the improper use of chemicals in aquaculture. Malachite green (MG) has attracted attention because of its illegal usage and its potential negative impacts on the environment and public health. Surface-enhanced Raman scattering (SERS) platforms coupled with different SERS substrates have been employed for rapid analysis of MG residues in food. However, the most commonly used SERS substrates were non-reusable and showed limited detection sensitivity. In this study, a novel SERS substrate with a good recyclability and a high sensitivity was prepared by electrostatically assembling together a metal-organic framework material called materials of institute lavoisie-100(Fe) (MIL-100(Fe)) and Au NPs. The lowest detectable concentration of MG was 10-13 M based on the optimal substrate. The SERS sensor was applied for the detection of the trace MG in fish pond water, which was accomplished with the correlation coefficients R2 = 0.991-0.996 in a concentration range of 10-6-10-13 M. Moreover, MIL-100(Fe)/Au was recycled at least five times, realizing a "detection to degradation", showing great potential for food contamination monitoring due to its distinguished performance.
Assuntos
Nanopartículas Metálicas , Análise Espectral Raman , Animais , Lagoas/análise , Corantes de Rosanilina/análise , Peixes , Água/análise , Ouro/química , Nanopartículas Metálicas/químicaRESUMO
It is necessary to determine whether synthetic dyes are present in food since their excessive use has detrimental effects on human health. For the simultaneous assessment of tartrazine and Patent Blue V, a novel electrochemical sensing platform was developed. As a result, two artificial azo colorants (Tartrazine and Patent Blue V) with toxic azo groups (-NN-) and other carcinogenic aromatic ring structures were examined. With a low limit of detection of 0.06 µM, a broad linear concentration range 0.09µM to 950µM, and a respectable recovery, scanning electron microscopy (SEM) was able to reveal the excellent sensing performance of the suggested electrode for patent blue V. The electrochemical performance of an electrode can be characterized using cyclic and differential pulse voltammetry, and electrochemical impedance spectroscopy. Moreover, the classification model was created by applying binary classification assessment using enhanced artificial intelligence comprises of support vector machine (SVM) and Genetic Algorithm (GA), respectively, a support vector machine and a genetic algorithm, which was then validated using the 50 dyes test set. The best binary logistic regression model has an accuracy of 83.2% and 81.1%, respectively, while the best SVM model has an accuracy of 90.3% for the training group of samples and 81.1% for the test group (RMSE = 0.644, R2 = 0.873, C = 205.41, and = 5.992). According to the findings, Cu-BTC MOF (copper (II)-benzene-1,3,5-tricarboxylate) has a crystal structure and is tightly packed with hierarchically porous nanomaterials, with each particle's edge measuring between 20 and 37 nm. The suggested electrochemical sensor's analytical performance is suitable for foods like jellies, condiments, soft drinks and candies.
Assuntos
Inteligência Artificial , Compostos Azo , Técnicas Eletroquímicas , Corantes de Alimentos , Contaminação de Alimentos , Corantes de Rosanilina , Tartrazina , Humanos , Compostos Azo/análise , Compostos Azo/isolamento & purificação , Técnicas Eletroquímicas/métodos , Eletrodos , Corantes de Alimentos/análise , Corantes de Alimentos/isolamento & purificação , Contaminação de Alimentos/prevenção & controle , Corantes de Rosanilina/análise , Corantes de Rosanilina/isolamento & purificaçãoRESUMO
In this research, we designed a rapid tricolour immunochromatographic test strip with double test lines (TS-DTL) and two-colour AuNP probes, which realised the simultaneous detection of tricaine mesylate (TMS) and malachite green (MG). Through a distinct tricolour system (red T1 line, blue T2 line and purple C line), a visual identification of TMS (0.2 µg/mL) and MG (0.5 µg/mL) was quickly achieved on site, which improved the accuracy of naked eye observations. The LODs of TMS in aquaculture water, fish and shrimp were 11.0, 29.6 and 61.4 ng/mL, respectively. MG LODs were 47.0 ng/mL (aquaculture water), 82.8 ng/mL (fish) and 152.4 ng/mL (shrimp). The LOD of MG was close to the similar TS methods. However, visual detection of TMS could meet the requirements of the residue limit (1 µg/mL) of TMS in the USA, and the quantitative detection of TMS was over 16 times lower than the USA standard. The developed platform was rapid (~20 min, HPLC~3 h) and accurate, which was verified using a traditional HPLC method. The recovery rates ranged from 82.2% to 108.6% in three types of real samples, indicating a potential application in on-site fast screening or multiple detection for TMS and MG residues in aquatic products.
Assuntos
Peixes , Corantes de Rosanilina , Aminobenzoatos , Animais , Imunoensaio , Limite de Detecção , Corantes de Rosanilina/análise , Água/análiseRESUMO
Magenta lilly pilly (Syzygium paniculatum) is an Australian native tree that produces berry fruits that are rich in phytochemicals reportedly beneficial to human health. Here we explored the biological activities of polyphenol-enriched extracts from the magenta lilly pilly fruit, benchmarking it against traditional sources including purple sweet potato and blackberry. We show that the extracts exert potent antioxidant and neuroprotective properties as well as antimicrobial activity against Staphylococcus aureus. The phenolic composition of lilly pilly was investigated using liquid chromatography coupled to mass spectrometry (HPLC-DAD-MS), revealing anthocyanins to be the primary component in high abundance compared to traditional anthocyanin-containing plants. Three anthocyanins from lilly pilly, along with their glycosylation patterns and stability, were characterised. Altogether, our results demonstrate the potential to exploit magenta lilly pilly fruits as a high-yielding source of phenolics with beneficial biological properties of potential interest for multiple downstream applications.
Assuntos
Polifenóis , Syzygium , Antocianinas/química , Antioxidantes/química , Austrália , Cromatografia Líquida de Alta Pressão , Frutas/química , Humanos , Fenóis/química , Extratos Vegetais/química , Polifenóis/análise , Polifenóis/farmacologia , Corantes de Rosanilina/análise , Syzygium/químicaRESUMO
Malachite green (MG) is an organic dye compound that is frequently used as a fungicide and antiseptic in aquaculture. However, human or animal exposure to MG causes carcinogenic, teratogenic and mutagenic effects. Herein, a novel fluorescent assay was designed for the detection of MG using manganese dioxide nanosheets (MnO2 NS) as an energy acceptor to quench the fluorescence of branched poly(ethylenimine) carbon dots (BPEI-CDs) via Förster resonance energy transfer. When butyrylcholinesterase is introduced to form thiocholine in the presence of S-butyrylthiocholine iodide, MnO2 NS can be recovered by thiocholine to Mn2+, resulting in restoration of the fluorescence of BPEI-CDs. Exploiting these changes in fluorescence intensity in the above system, a fluorescence probe was successfully developed for the quantitative detection of MG. Besides, this assay was applied to fish samples, verifying the high potential for practical application of the proposed sensor for the monitoring of MG in aquatic products.
Assuntos
Medições Luminescentes , Pontos Quânticos , Animais , Aquicultura , Butirilcolinesterase , Carbono/química , Peixes , Corantes Fluorescentes/química , Limite de Detecção , Medições Luminescentes/métodos , Compostos de Manganês/química , Nanoestruturas/química , Óxidos , Polietilenoimina , Pontos Quânticos/química , Corantes de Rosanilina/análise , Corantes de Rosanilina/química , TiocolinaRESUMO
Accurate and rapid quantitative detection of pesticide and pollutant levels in the actual sample can aid in protecting food security, environmental security, and human health. A high Raman enhancement factor and good repeatability of the surface-enhanced Raman spectroscopy (SERS) substrates are favorable to quantitative analysis. Herein, a quantitative SERS sensor based on constructed self-assembled plasmonic Au@Ag heterogeneous nanocuboids (Au@Ag NCs) monolayer was developed. The sensor was used to quantitatively detect the trace pesticides extracted from pear surfaces and pollutants in fishpond water. Densely packed Au@Ag NCs fabricated into large-scale monolayer films were chemically functionalized using 4-methyl-thiobenzoic acid (4-MBA) at the organic/aqueous interface, in which plentiful nanogaps contribute to increase hotspots. Their sharp corners and edges make the sensor have high SERS performance through providing abundant "hot spots." The obtained optically SERS-based sensor with uniform liquid-state interfacial nanoparticle arrays appeared to have nice SERS performance and uniformity using crystal violet (CV) as a probe molecule. In particular, the proposed SERS sensor was applied for quantitative detection of thiabendazole (TBZ) extracted from pear surfaces and malachite green (MG) in fishpond water down to levels of 0.0105 nM and 0.87 nM for SERS assay respectively. As a result, our proposed SERS quantitative detection strategy is quite preferred to on-site analysis and supervision of contaminant in food samples.
Assuntos
Ouro/química , Nanopartículas Metálicas/química , Praguicidas/análise , Prata/química , Análise Espectral Raman/métodos , Poluentes Químicos da Água/análise , Água Doce/análise , Frutas/química , Nanopartículas Metálicas/ultraestrutura , Pyrus/química , Corantes de Rosanilina/análise , Tiabendazol/análiseRESUMO
With growing human culture and industrialization, many pollutants are being introduced into aquatic ecosystems. In recent years, dyes have become a major water pollutant used in the manufacture of paints and other production purposes. In this research, the potential of duckweed (Lemna gibba) plant was investigated spectrophotometrically as an obvious bioagent for the biological decolorization of the organic dye C.I. Basic Green 4 (Malachite Green, BG4). Photosynthetic efficiency analysis showed that the photosynthetic apparatus of L. gibba is very tolerant to BG4. Significant induction of reactive oxygen species (ROS) scavenging enzymes was observed after 24h of biodecolorization process in L. gibba treated with 15 and 30 mg/l BG4. The experimental results showed that L. gibba has a strong ability to extract BG4 from contaminated water and the best results were obtained at 25-30°C and pH 8.0. We conclude that duckweed L. gibba can be used as a potent decolorization organism for BG4.
Assuntos
Araceae/crescimento & desenvolvimento , Corantes de Rosanilina/análise , Poluentes Químicos da Água/análise , Araceae/metabolismo , Biodegradação Ambiental , Fotossíntese , Espécies Reativas de Oxigênio/metabolismo , EspectrofotometriaRESUMO
A qualitative and quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the sensitive and exhaustive analysis of residues from triarylmethane dyes, triarylmethane-derivative dyes, phenothiazines, phenoxazines and xanthenes in aquaculture samples. For a wider and more robust detection of dye misuse on farms, other residue markers were also included the leuco forms of brilliant green, crystal violet and malachite green; one direct metabolite of Victoria pure blue BO and methylene blue and three bile acids, which are endogenous markers of the effects of dye contamination in fish. We optimised the extraction method by comparing several extraction solvents and sample solvents reported in the literature to have the best extraction efficiency. The residues were determined using a positive electrospray ionisation source. We assessed the parameters of this LC-MS/MS method by evaluating the matrix effects, identification and quantitative parameters according to the criteria stipulated in the European Commission Decision No. 2002/657/EC. A study on the applicability of the method was conducted on various aquaculture species and on a positive catfish.
Assuntos
Aquicultura/métodos , Corantes/análise , Uso Indevido de Medicamentos/prevenção & controle , Resíduos de Drogas/análise , Contaminação de Alimentos/análise , Poluentes Químicos da Água/análise , Animais , Ácidos e Sais Biliares/análise , Peixes-Gato , Cromatografia Líquida de Alta Pressão , Corantes/efeitos adversos , Violeta Genciana/análise , Humanos , Músculos/química , Compostos de Amônio Quaternário/análise , Corantes de Rosanilina/análise , Espectrometria de Massas em Tandem , Extratos de Tecidos/químicaRESUMO
Film wrap nanoparticle system (FWPS) is proposed and fabricated to perform SERS effect, where the Ag nanoparticle was completely wrapped by Au film and the double-layered graphene was selected as the sub-nano spacer. In this system, the designed nanostructure can be fully rather than partly used to generate hotspots and absorb probe molecules, compared to the nanoparticle to nanoparticle system (PTPS) or nanoparticle to film system (PTFS). The optimal fabricating condition and performance of this system were studied by the COMSOL Multiphysics. The simulation results show that the strongly large-scale localized electromagnetic field appears in the whole space between the Ag nanoparticle and Au film. The experimental results show that the FWPS presents excellent sensitivity (crystal violet (CV): 10-11 M), uniformity, stability and high enhancement factor (EF: 2.23×108). Malachite green (MG; 10-10 M) on the surface of fish and DNA strands with different base sequence (A, T, C) were successfully detected. These advanced results indicate that FWPS is highly promising to be applied for the detection of environmental pollution and biomolecules.
Assuntos
DNA/análise , Violeta Genciana/análise , Grafite/química , Nanopartículas Metálicas/química , Corantes de Rosanilina/análise , Análise Espectral Raman/métodos , Poluentes Químicos da Água/análise , Animais , Peixes/fisiologia , Prata/químicaRESUMO
An ingenious nanoscale fluorescent sensor derived from Eu3+-postfunctionalized MIL-53 (Al) (Eu3+@MIL-53 [Al]) was fabricated though a simple and effective approach. Malachite green (MG) effectively turned off the luminescence of Eu3+@MIL-53 (Al) via fluorescence resonance energy transfer (FRET), thus enabling MG sensing. The developed probe exhibited instantaneous reusability after being cleaned with deionized water. The fluorescence intensity, quenching efficiency, and crystal structure of the recoverable sensor after five recycling processes were unchanged compared with those of the original sample. Moreover, the potential mechanism of MG detection was revealed in detail. This work represents the first attempt to determine MG in aquaculture water and products by using metal-organic frameworks (MOFs). The Eu3+@MIL-53 (Al) probe proved to be a remarkable fluorescence probe for MG with high selectivity, sensitivity, and excellent regeneration capability. It provides a promising functional platform for the recognition of illegal MG addition to aquaculture water and products.
Assuntos
Európio/química , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes/química , Estruturas Metalorgânicas/química , Nanoestruturas/química , Corantes de Rosanilina/análise , Corantes de Rosanilina/química , Água/químicaRESUMO
To determine malachite green (MG) and its major metabolite, leucomalachite green (LMG) residual levels in tilapia fish, chemiluminescent enzyme immunoassay (CLEIA) was developed based on a single-chain variable fragment (scFv)-alkaline phosphatase (AP) fusion protein. At first, VH and VL gene sequences were cloned from hybridoma cell lines secreting monoclonal antibody against LMG, and then thoroughly by database-assisted sequence analysis. Finally, the productive VH and VL were assembled to an intact scFv sequence and engineered to produce scFv-AP fusion protein. The fusion protein was further identified as a bifunctional reagent for immunoassay, then a sensitive one-step CLEIA against LMG was developed with a half-maximal inhibitory concentration (IC50) and limit of detection (LOD) of 1.3 and 0.04 ng/mL, respectively. The validation results of this novel competitive CLEIA was in line with those obtained by classical HPLC method for determination of total MG in spiked and field incurred samples.