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1.
Chembiochem ; 25(7): e202300742, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38426686

RESUMO

Pesticides are essential in agricultural development. Controlled-release pesticides have attracted great attentions. Base on a principle of spatiotemporal selectivity, we extended the photoremovable protective group (PRPG) into agrochemical agents to achieve controllable release of active ingredients. Herein, we obtained NP-TBZ by covalently linking o-nitrobenzyl (NP) with thiabendazole (TBZ). Compound NP-TBZ can be controlled to release TBZ in dependent to light. The irradiated and unirradiated NP-TBZ showed significant differences on fungicidal activities both in vitro and in vivo. In addition, the irradiated NP-TBZ displayed similar antifungal activities to the directly-used TBZ, indicating a factual applicability in controllable release of TBZ. Furthermore, we explored the action mode and microcosmic variations by SEM analysis, and demonstrated that the irradiated NP-TBZ retained a same action mode with TBZ against mycelia growth.


Assuntos
Praguicidas , Tiabendazol , Tiabendazol/farmacologia , Tiabendazol/análise , Preparações de Ação Retardada , Antifúngicos/farmacologia
2.
Talanta ; 272: 125829, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38422907

RESUMO

Development of efficient and intelligent method for detecting harmful agrochemicals in resource-limited settings remains an urgent need to ensure food and environmental safety. Herein, a novel dual-emitting Tb3+-modified hydrogen-bonded organic framework (Tb@TBTC, TBTC is the ligand of HOF-TBTC.) with visible green fluorescence has been prepared through coordination post-synthetic modification. Tb@TBTC can be designed as a fluorescence sensor for the identification of two harmful carcinogenic pesticides, thiabendazole (TBZ) and 2-chlorophenol (2-CP) with high sensitivity, high efficiency and excellent selectivity. Tb@TBTC can also adsorb 2-CP with high adsorption rate. In realistic fruit juice and river water samples, the detection limits of Tb@TBTC toward TBZ and 2-CP are as low as 2.73 µM and 2.18 µM, respectively, demonstrating the feasibility in practical application. Furthermore, an intelligent real-time and on-site monitoring platform for 2-CP detection is constructed based on Tb@TBTC-agarose hydrogel films with the assistance of back propagation neural network, which can efficiently and accurately determine the concentration of 2-CP from fluorescence images through human-machine interaction. This work presents a facile pathway to prepare Tb@HOF fluorescent sensor for food and ecological environment safety, which is highly promising for preventing human disease and improving global public health.


Assuntos
Clorofenóis , Alimentos , Tiabendazol , Humanos , Tiabendazol/análise , Sucos de Frutas e Vegetais
3.
Anal Bioanal Chem ; 416(2): 497-508, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38001372

RESUMO

Pesticides that linger in the environment and ecosystems for an extended period can cause severe and dangerous health problems in humans. To detect pesticides in foods, the development of high-sensitivity and quick screening technologies was required. This research investigated the performance of Au@Ag NPs with varying thicknesses of the silver shell for detecting trace quantities of thiabendazole (TBZ) in apples using surface-enhanced Raman spectroscopy (SERS). The Au@Ag NPs were synthesized by coating 32 nm gold seeds with different thicknesses of silver shell ranging from 2.4 to 8.7 nm, achieved by adjusting the incorporation of AgNO3 and ascorbic acid. The optimized Au@Ag NPs with a 7.3 nm silver shell demonstrated outstanding SERS activity, high sensitivity, and a detection limit of 0.05 µg/mL for TBZ. The R2 values, representing the goodness of fit, were found to be 0.990 and 0.986 for standard and real TBZ samples, respectively, indicating a strong correlation between the measured signal and the TBZ concentration. The recovery analysis showed a reliable and accurate detection capability (96 to 105%), suggesting good reliability and accuracy of the SERS-based detection using the optimal Au@Ag NPs. Overall, this research highlights the potential of SERS with optimal Au@Ag NPs for rapid and effective monitoring of pesticides in the food industry.


Assuntos
Malus , Nanopartículas Metálicas , Praguicidas , Humanos , Malus/química , Tiabendazol/análise , Prata/química , Reprodutibilidade dos Testes , Ecossistema , Nanopartículas Metálicas/química , Análise Espectral Raman/métodos , Praguicidas/análise , Ouro/química
4.
Food Chem ; 440: 138214, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38150903

RESUMO

Pesticide residue poses a significant global public health concern, necessitating improved detection methods. Here, a novel platform was introduced based on surface-enhanced Raman spectroscopy (SERS) to detect ten distinct types of pesticides. Notably, the sensitivity of this approach is exemplified by detecting trace amounts of 50 pM (10 ppt) thiabendazole. The correlation between the characteristic peak intensity of coexisting pesticides and their concentrations displays an exceptional linear relationship (R2 = 0.9999), underscoring its utility for quantitative mixed pesticide detection. Additionally, qualitative analysis of five mixed pesticides was conducted leveraging distinctive peak labeling. Harnessing machine learning techniques, a model for classifying and predicting pesticides on pericarps was developed. Remarkably, the convolutional neural network achieved classification accuracy of 100 % and prediction accuracy of 99.62 %. This innovative approach accurately identifies and quantifies diverse pesticides, thus offering a feasible scheme for in-situ detection of pesticide residues. Ultimately, this strategy contributes to ensuring food safety and public health.


Assuntos
Resíduos de Praguicidas , Praguicidas , Resíduos de Praguicidas/análise , Análise Espectral Raman/métodos , Praguicidas/análise , Inocuidade dos Alimentos , Tiabendazol/análise
5.
J Am Soc Mass Spectrom ; 34(11): 2461-2468, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37804228

RESUMO

There is an increasing need for developing a strategy to analyze the penetration of pesticides in cultures during postharvest control with minimal or no sample preparation. This study explores the combined use of laser ablation electrospray ionization mass spectrometry imaging (LAESI imaging) and tissue spray ionization mass spectrometry (TSI-MS) to investigate the penetration of thiabendazole (TBZ) in fruits, simulating a postharvest procedure. Slices of guava and apple were prepared, and an infrared laser beam was used, resulting in the ablation of TBZ directly ionized by electrospray and analyzed by mass spectrometry. The experiments were conducted for 5 days of fruit storage after TBZ administration to simulate a postharvest treatment. During postharvest treatment, TBZ is applied directly to the fruit peel after harvesting. Consequently, TBZ residues may remain on the peel if the consumer does not wash the fruit properly before its consumption. To evaluate the effectiveness of household washing procedures, TSI-MS was employed as a rapid and straightforward technique to monitor the remaining amount of TBZ in guava and apple peels following fruit washing. This study highlights the advantages of LAESI imaging for evaluating TBZ penetration in fruits. Moreover, the powerful capabilities of TSI-MS are demonstrated in monitoring and estimating TBZ residues after pesticide application, enabling the comprehensive unveiling of pesticide contaminants in fruits.


Assuntos
Praguicidas , Praguicidas/análise , Frutas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Tiabendazol/análise
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 303: 123189, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37506455

RESUMO

In recent years, the excessive use of pesticides has posed significant hazards to the ecological environment and human health in the pursuit of high crop yields. In this work, we developed a simple, sensitive, and eco-friendly approach for rapid detection of thiabendazole in apple juice using surface-enhanced Raman scattering (SERS) coupled with silver-coated gold nanoparticles (Au@Ag NPs). The developed Au@Ag NPs exhibited excellent sensitivity, allowing for the detection of thiabendazole in standard solutions at a minimum concentration of 50 ng/mL. Furthermore, two sample preparation methods were compared for detecting thiabendazole in apple juice. As the direct detection method for SERS analysis failed to detect thiabendazole at levels below the maximum residue limit based on the Chinese standard (3000 ng/mL), the effects of main matrix components in apple juice on the detection of thiabendazole were further investigated. The results revealed that both sugars and organic acids in apple juice interfered with the SERS measurement to varying degrees. Consequently, we optimized the QuEChERS method for sample preparation and achieved a higher sensitivity with a minimum detectable concentration of 250 ng/mL, a limit of detection of 0.06 mg/L and the recoveries of spiked samples were ranged from 80.2 % to 108.6 %. This study demonstrated the feasibility of proposed SERS method for pesticide residue analysis, addressing the need for food safety monitoring.


Assuntos
Malus , Nanopartículas Metálicas , Humanos , Malus/química , Ouro/química , Tiabendazol/análise , Prata/química , Análise Espectral Raman/métodos , Contaminação de Alimentos/análise , Nanopartículas Metálicas/química
7.
Food Chem ; 424: 136479, 2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37263093

RESUMO

In this study, surface-enhanced Raman spectroscopy (SERS) combined with chemometric methods were developed for qualitative and quantitative analysis of four benzimidazole (BMZs) residues in corn. Sulfhydryl functionalized Fe3O4@SiO2@Ag-SH magnetic SERS substrates were prepared to obtain the SERS spectra of four BMZs for chemometric analysis. The partial least squares regression discrimination analysis (PLS-DA) model performed best, with a recall rate upwards 99.17%, and could successfully distinguish four BMZs. Under the support vector machine regression (SVR) model, the detection limits of carbendazim, benomyl, thiophanate-methyl and thiabendazole were 0.055 mg/L, 0.056 mg/L, 0.067 mg/L and 0.093 mg/L, respectively; the average recovery was in the range of 85.6%-107.5%. Furthermore, the method verified by HPLC, and the results showed that there was no significant difference between two methods (p > 0.05). Therefore, the strategy based on SERS coupling chemometrics can be served as a promising tool for rapid determination of BMZs residues in food.


Assuntos
Nanopartículas Metálicas , Análise Espectral Raman , Análise Espectral Raman/métodos , Quimiometria , Dióxido de Silício , Benzimidazóis/análise , Tiabendazol/análise , Nanopartículas Metálicas/química
8.
J Biosci Bioeng ; 136(2): 123-128, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37296042

RESUMO

Cold atmospheric plasma (CAP) irradiation has a sterilizing effect without thermal denaturation or the production of residual substances. Hence, it is considered to be a safe sterilization technology with minimal damage for fresh foods. In addition, its decomposition effect on chemical substances has also been confirmed, and the application of CAP in the food and agricultural domains is increasing. In this study, we examined the potential of CAP to detoxify pesticide residues. Post-harvest chemical treatments using pesticides, such as fungicides, are frequently employed in imported agricultural products and are often disapproved by consumers. Therefore, we assessed the detoxification of thiabendazole (TBZ), a widely used post-harvest pesticide, using low-cost air plasma irradiation. We found that CAP irradiation conditions that detoxified TBZ caused little damage to the edible parts of mandarin oranges. The results of the present study suggest that CAP irradiation is useful for detoxifying and degrading pesticide residues without damaging agricultural products and that CAP irradiation is an effective means of maintaining food safety.


Assuntos
Resíduos de Praguicidas , Praguicidas , Gases em Plasma , Antifúngicos , Tiabendazol/análise
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 301: 122954, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37270975

RESUMO

Pesticide active ingredients (AIs) are often applied with adjuvants to facilitate the stability and functionality of AIs in agricultural practice. The objective of this study is to investigate the role of a common non-ionic surfactant, alkylphenol ethoxylate (APEO), on the surface-enhanced Raman spectroscopic (SERS) analysis of pesticides as well as its impact on pesticide persistence on apple surfaces, as a model fresh produce surface. The wetted areas of two AIs (thiabendazole and phosmet) mixed with APEO were determined respectively to correct the unit concentration applied on apple surfaces for a fair comparison. SERS with gold nanoparticle (AuNP) mirror substrates was applied to measure the signal intensity of AIs with and without APEO on apple surfaces after a short-term (45 min) and a long-term (5 days) exposure. The limit of detection (LOD) of thiabendazole and phosmet using this SERS-based method were 0.861 ppm and 2.883 ppm, respectively. The result showed that APEO decreased the SERS signal for non-systemic phosmet, while increased SERS intensity of systemic thiabendazole on apple surfaces after 45 min pesticide exposure. After 5 days, the SERS intensity of thiabendazole with APEO was higher than thiabendazole alone, and there was no significant difference between phosmet with and without APEO. Possible mechanisms were discussed. Furthermore, a 1% sodium bicarbonate (NaHCO3) washing method was applied to test the impact of APEO on the persistence of the residues on apple surfaces after short-term and long-term exposures. The results indicated that APEO significantly enhanced the persistence of thiabendazole on plant surfaces after a 5-day exposure, while there was no significant impact on phosmet. The information obtained facilitates a better understanding of the impact of the non-ionic surfactant on SERS analysis of pesticide behavior on and in plants and helps further develop the SERS method for studying complex pesticide formulations in plant systems.


Assuntos
Malus , Nanopartículas Metálicas , Praguicidas , Fosmet , Praguicidas/análise , Malus/química , Fosmet/análise , Tensoativos , Ouro/química , Tiabendazol/análise , Nanopartículas Metálicas/química , Lipoproteínas
10.
Molecules ; 28(9)2023 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-37175335

RESUMO

Thiabendazole (TBZ) is a fungicide and anthelmintic drug commonly found in food products. Due to its toxicity and potential carcinogenicity, its determination in various samples is important for public health. Different analytical methods can be used to determine the presence and concentration of TBZ in samples. Liquid chromatography (LC) and its subtypes, high-performance liquid chromatography (HPLC) and ultra-high-performance liquid chromatography (UHPLC), are the most commonly used methods for TBZ determination representing 19%, 18%, and 18% of the described methods, respectively. Surface-enhanced Raman spectroscopy (SERS) and fluorimetry are two more methods widely used for TBZ determination, representing 13% and 12% of the described methods, respectively. In this review, a number of methods for TBZ determination are described, but due to their limitations, there is a high potential for the further improvement and development of each method in order to obtain a simple, precise, and accurate method that can be used for routine analysis.


Assuntos
Fungicidas Industriais , Tiabendazol , Tiabendazol/análise , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Fungicidas Industriais/análise , Fluorometria
11.
Food Chem ; 402: 134379, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36179525

RESUMO

The development of effective electrochemical methods for the determination of pesticide residues is highly desirable for food safety requirements. Herein, a novel electrochemical sensing strategy for indirect detection of thiabendazole (TBZ) was achieved by monitoring the anodic stripping peak signal change of media Cu2+ induced by a significant activity difference between active Cu2+ and inactive Cu2+-TBZ complexes. In this sensing system, a heterostructured Ti3C2Tx-TiO2 composite synthesized via a simple in-situ-oxidization strategy is used as the electrode material to boost the anodic stripping peak signal. After optimizing various conditions, the developed sensor presents satisfactory analytical performance for TBZ assay with a linear range from 0.3 to 100.0 nM and a limit of detection as low as 0.1 nM (S/N = 3). Furthermore, the proposed sensing platform also exhibits outstanding anti-interference, repeatability, and stability, which is effective for the determination of TBZ in fruit and water samples.


Assuntos
Resíduos de Praguicidas , Tiabendazol , Tiabendazol/análise , Frutas/química , Resíduos de Praguicidas/análise , Titânio/análise , Água/análise , Eletrodos
12.
Food Chem ; 405(Pt A): 134794, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36368104

RESUMO

Pesticide residues in fruit and vegetable constitute a great threat to mankind's health, and a technique of rapid, cost-effective, ultra-sensitive and non-destructive analysis is especially critical for on-site detection in practical application. A strategy was utilized to fabricate highly viscous and flexible WPU@AgNPs sticky tape for the rapid extraction and Surface-enhanced Raman Scattering (SERS) assay of thiabendazole residues on the surface of fruits. Simply put, the novel WPU@AgNPs tapes were constructed by decorating the waterborne polyurethane (WPU) film with silver nanoparticles (AgNPs), and demonstrated excellent sensitivity with 4-Mercaptopyridine (4-Mpy) as the probe molecule. Meanwhile, the enhancement factor of the novel SERS substrate could reach 7.01 × 106, which was consistent with the finite difference time domain (FDTD) theoretical simulation results. What's more, the high viscosity and flexibility of WPU@AgNPs sticky tapes allowed them to detect the thiabendazole residues on the pear, apple and banana surfaces by a straightforward "paste and peel off" approach. The results showed that the detection limit could reach 1.44, 1.12 and 1.63 ng/cm2. This strategy would be as a common method for prompt, on-site and ultra-sensitive assay of thiabendazole residues in chemical and biological fields.


Assuntos
Nanopartículas Metálicas , Resíduos de Praguicidas , Resíduos de Praguicidas/análise , Análise Espectral Raman/métodos , Nanopartículas Metálicas/química , Tiabendazol/análise , Prata/química
13.
Food Chem ; 405(Pt A): 134713, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36335731

RESUMO

Thiabendazole (TBZ), a benzimidazole fungicide used for post-harvest treatment, may be a trace contaminant of food matrices. In this work, we report the first EC-SERS (electrochemical-surface enhanced Raman spectroscopy) detection of TBZ in spiked apple juice using electrochemically (EC) roughened, gold-based screen-printed electrodes (AuSPEs) and portable instrumentation. Polarizing the substrate (-0.8 V vs Ag/AgCl) improves the recorded SERS signal of TBZ, allowing to reach a limit of detection (LOD) in juice of 0.061 ppm with a relatively wide linear range (0.5-10 µM) and good intermediate precision (%RSD < 10). The recovery of TBZ from unprocessed juice was found to be more than 82 %. Furthermore, a proof-of-concept integration of AuSPEs with a miniaturized flow cell for the preconcentration of TBZ and the controlled delivery of sample and reagents has been demonstrated. This approach paves the way for integrated, portable analytical systems applicable for on-site sample collection, processing, and analysis.


Assuntos
Malus , Nanopartículas Metálicas , Tiabendazol/análise , Malus/química , Ouro/química , Sucos de Frutas e Vegetais/análise , Análise Espectral Raman/métodos , Eletrodos , Nanopartículas Metálicas/química
14.
Molecules ; 27(23)2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36500391

RESUMO

During the postharvest period, citrus fruits are exposed to Penicillium italicum, Penicillium digitatum, and Geotrichum candidum. Pesticides such as imazalil (IMZ), thiabendazole (TBZ), orthophenylphenol (OPP), and guazatine (GUA) are commonly used as antifungals. Glyphosate (GP) is also used in citrus fields to eliminate weed growth. The sensitivity of fungal pathogens of citrus fruit to these pesticides and 1,8-cineole was evaluated, and the effect of GP on the development of cross-resistance to other chemicals was monitored over a period of 3 weeks. IMZ most effectively inhibited the mycelial growth and spore germination of P. digitatum and P. italicum, with minimum inhibitory concentrations (MICs) of 0.01 and 0.05 mg/mL, respectively, followed by 1,8-cineole, GP, and TBZ. 1,8-Cineole and GP more effectively inhibited the mycelial growth and spore germination of G. candidum, with minimum inhibitory concentrations (MICs) of 0.2 and 1.0 mg/mL, respectively, than OPP or GUA. For the spore germination assay, all substances tested showed a total inhibitory effect. Subculturing the fungal strains in culture media containing increasing concentrations of GP induced fungal tolerance to GP as well as to the fungicides. In soil, experiments confirmed that GP induced the tolerance of P. digitatum to TBZ and GP and the tolerance of P. italicum to IMZ, TBZ, and GP. However, no tolerance was recorded against 1,8-cineole. In conclusion, it can be said that 1,8-cineole may be recommended as an alternative to conventional fungicides. In addition, these results indicate that caution should be taken when using GP in citrus fields.


Assuntos
Citrus , Fungicidas Industriais , Penicillium , Citrus/química , Eucaliptol/farmacologia , Fungicidas Industriais/farmacologia , Fungicidas Industriais/análise , Tiabendazol/análise , Antifúngicos/farmacologia , Antifúngicos/análise , Frutas/química
15.
Sensors (Basel) ; 22(24)2022 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-36560348

RESUMO

Rapid analysis of components in complex matrices has always been a major challenge in constructing sensing methods, especially concerning time and cost. The detection of pesticide residues is an important task in food safety monitoring, which needs efficient methods. Here, we constructed a machine learning-assisted synchronous fluorescence sensing approach for the rapid and simultaneous quantitative detection of two important benzimidazole pesticides, thiabendazole (TBZ) and fuberidazole (FBZ), in red wine. First, fluorescence spectra data were collected using a second derivative constant-energy synchronous fluorescence sensor. Next, we established a prediction model through the machine learning approach. With this approach, the recovery rate of TBZ and FBZ detection of pesticide residues in red wine was 101% ± 5% and 101% ± 15%, respectively, without resorting complicated pretreatment procedures. This work provides a new way for the combination of machine learning and fluorescence techniques to solve the complexity in multi-component analysis in practical applications.


Assuntos
Resíduos de Praguicidas , Vinho , Tiabendazol/análise , Resíduos de Praguicidas/análise , Vinho/análise , Fluorescência , Benzimidazóis
16.
Food Chem ; 370: 131276, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34662790

RESUMO

This study presented an effective and sensitive SERS substrate for rapid detection of thiabendazole (TBZ) in fruit samples. A core-shell gold/silver nanorod (Au@Ag NRs) has been synthesized as a bimetallic SERS-active substrate. The obtained substrate showed an excellent SERS effect because of the tunable plasmon resonance of Au NRs, the significantly enhanced effect of silver, and the bimetallic synergistic effect of Au@Ag NRs. Under optimal conditions, the substrate was used to detect TBZ in fresh apple juice and peach juice with limits of detection of 0.032 and 0.034 ppm respectively. In addition, the recovery rate was within a satisfactory range of 95-101%, indicating that the Au@Ag NRs substrate could be a SERS detection platform for fruit pesticides residues with great development potential.


Assuntos
Nanopartículas Metálicas , Nanotubos , Sucos de Frutas e Vegetais , Ouro , Análise Espectral Raman , Tiabendazol/análise
17.
Anal Bioanal Chem ; 413(30): 7485-7494, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34642782

RESUMO

Excessive use of pesticides in modern agriculture results in large amounts of pesticide residues in agricultural production, greatly threatening human health. Herein, novel two-dimensional leaf-like zeolitic imidazolate framework-L decorated with multi-walled carbon nanotubes (MWCNTs/ZIF-L) was prepared by a facile solvent way and exploited as electrode material for sensitive electrochemical sensing of thiabendazole (TBZ). Two-dimensional ZIF-L presents high surface area, large pore volume, and abundant active sites, which exhibits high enrichment ability towards TBZ molecules, while the MWCNTs interspersed on ZIF-L can prominently enhance the electron transport capability and improve the electrocatalytic activity for TBZ oxidation. Due to the intriguing synergy between the components, the MWCNTs/ZIF-L-based electrochemical sensor reveals a limit of detection (LOD) of 6.0 nmol·L-1, which is lower than that reported in most literatures. Additionally, satisfactory reproducibility and repeatability, long-term stability, and excellent selectivity are acquired. The proposed method was also applied for the detection of TBZ in apple and orange samples with acceptable recoveries.


Assuntos
Técnicas Eletroquímicas/instrumentação , Estruturas Metalorgânicas/química , Nanotubos de Carbono/química , Resíduos de Praguicidas/análise , Tiabendazol/análise , Eletrodos , Limite de Detecção , Microscopia Eletrônica de Varredura , Reprodutibilidade dos Testes , Zeolitas/química
18.
Artigo em Inglês | MEDLINE | ID: mdl-34157962

RESUMO

Modification of surface-enhanced Raman spectroscopy (SERS) substrates with thiol ligands is an emerging approach in enhancing the stability and sensitivity of metal substrates due to their good affinity with metals such as Au, Ag, and Cu. Thus, in the current study, 2-mercaptoethanol was used to modify the surface of silver-coated gold nanoparticles to develop a novel SERS substrate for the rapid assessment of fungicide residues in fruit samples. Results showed that the substrate could achieve the detection of ferbam and thiabendazole residues in apple puree with limits of detection of approximately 0.0042 and 0.0064 ppm, high coefficients of determination of 0.9946 and 0.9968, good recoveries ranging from 80 to 105 and 81 to 107% and relative standard deviations of 3.5-7.5 and 3.8-7.9 %, respectively. Therefore, the substrate developed could potentially be utilised to assess other toxic agrochemicals in future.


Assuntos
Ligas/química , Dimetilditiocarbamato/análise , Contaminação de Alimentos/análise , Fungicidas Industriais/análise , Nanopartículas Metálicas/química , Tiabendazol/análise , Frutas/química , Ouro/química , Humanos , Malus/química , Mercaptoetanol/química , Prata/química , Análise Espectral Raman
19.
Anal Bioanal Chem ; 413(16): 4207-4215, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33987702

RESUMO

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/análise
20.
Sud Med Ekspert ; 64(3): 34-40, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34013693

RESUMO

OBJECTIVE: Is to study the features and to develop the methods for the determination of thiabendazole in the tissues of cadaveric organs and blood. When performing the experiments the methods of TLC, GC-MS and spectrophotometry were used. The advantages were substantiated and the optimal conditions for the release of thiabendazole from the tissues of organs and blood with acetone were determined. A variant of purification of the substance extracted from biomatrixes by the method of column chromatography of normal pressure (sorbent L 40/100 µm, mobile phase acetone-dichloromethane (9.5: 0.5)) is proposed. To identify the analyte by TLC the Sorbfil plates were used and a toluene-acetonitrile mobile phase (2:8). When identifying thiabendazole by a combination of gas-liquid chromatography and mass spectrometry (fragmentation of molecules by electron impact 70 eV) an HP-5MS column 30 m × 0.25 mm with a non-polar stationary phase (5% -phenyl) -methylpolysiloxane was proposed. The expediency of the spectrophotometric determination of thiabendazole on the basis of absorption in an acetonitrile medium has been shown. Methods for the determination of thiabendazole in tissues of organs and blood have been developed and validated. It is shown that the techniques meet the requirements of linearity, selectivity, correctness, precision and stability. The limits of detection of thiabendazole in the liver and blood are 0.14 and 0.10 mg, respectively; the limits of quantitative determination are 0.26 and 0.18 mg per 100 g of biomatrix.


Assuntos
Materiais Biocompatíveis , Tiabendazol , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Espectrometria de Massas , Espectrofotometria , Tiabendazol/análise , Tiabendazol/toxicidade
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