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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 324: 125011, 2025 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-39213831

RESUMO

Thiols function as antioxidants in food, prolonging shelf life and enhancing flavor. Moreover, thiols are vital biomolecules involved in enzyme activity, cellular signal transduction, and protein folding among critical biological processes. In this paper, the fluorescent probe PYL-NBD was designed and synthesized, which utilized the fluorescent molecule pyrazoline, the lysosome-targeted morpholine moiety, and the sensing moiety NBD. Probe PYL-NBD was tailored for the recognition of biothiols through single-wavelength excitation, yielding distinct fluorescence emission signals: blue for Cys, Hcy, and GSH; green for Cys, Hcy. Probe PYL-NBD exhibited rapid reaction kinetics (<10 min), distinct fluorescence response signals, and low detection limits (15.7 nM for Cys, 14.4 nM for Hcy, and 12.6 nM for GSH). Probe PYL-NBD enabled quantitative determination of Cys content in food samples and L-cysteine capsules. Furthermore, probe PYL-NBD had been successfully applied for confocal imaging with dual-channel detection of biothiols in various biological specimens, including HeLa cells, zebrafish, tumor sections, and Arabidopsis thaliana.


Assuntos
Cisteína , Corantes Fluorescentes , Análise de Alimentos , Glutationa , Lisossomos , Espectrometria de Fluorescência , Peixe-Zebra , Humanos , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Lisossomos/química , Lisossomos/metabolismo , Células HeLa , Cisteína/análise , Animais , Análise de Alimentos/métodos , Glutationa/análise , Espectrometria de Fluorescência/métodos , Homocisteína/análise , Arabidopsis/química , Limite de Detecção , Microscopia Confocal
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 324: 124950, 2025 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-39133976

RESUMO

Low fluorescence under visible light excitation and catalytic activity limit many applications of graphene quantum dots in optical detection, biosensing, catalysis and biomedical. The paper reports design and synthesis of histidine, serine and folic acid-functionalized and boron and iron-doped graphene quantum dot (Fe/B-GQD-HSF). The Fe/B-GQD-HSF shows excellent fluorescence behavior and peroxidase-like activity. Excitation of 330 nm ultraviolet light produces the strongest blue fluorescence and excitation of 480 nm visible light produces the strongest yellow fluorescence. The specific activity reaches 92.67 U g-1, which is higher than that of other graphene quantum dots. The Fe/B-GQD-HSF can catalyze oxidation of 3,3',5,5'-tetramethylbenzidine with H2O2 to form blue compound. Based on this, it was used for colorimetric and fluorescence detection of H2O2. The absorbance at 652 nm linearly increases with the increase of H2O2 concentration between 0.5 and 100 µM with detection limit of 0.43 µM. The fluorescence signal linearly decreases with the increase of H2O2 concentration between 0.05 and 100 µM with detection limit of 0.035 µM. The analytical method has been satisfactorily applied in detection of H2O2 in food. The study also paves one way for design and synthesis of functional graphene quantum dots with ideal fluorescence behavior and catalytic activity.


Assuntos
Boro , Colorimetria , Ácido Fólico , Grafite , Histidina , Peróxido de Hidrogênio , Ferro , Pontos Quânticos , Serina , Pontos Quânticos/química , Grafite/química , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/química , Colorimetria/métodos , Ácido Fólico/análise , Ácido Fólico/química , Ferro/análise , Ferro/química , Boro/química , Histidina/análise , Histidina/química , Serina/análise , Serina/química , Espectrometria de Fluorescência/métodos , Limite de Detecção , Análise de Alimentos/métodos , Peroxidase/química , Peroxidase/metabolismo , Catálise
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 324: 124975, 2025 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-39154402

RESUMO

Epilepsy is one of the most commonly-seen neurological disorders, and both endoplasmic reticulum stress (ERS) and oxidative stress (OS) have been demonstrated to be associated with epileptic seizures. As one of the three endogenous thiol-containing amino acids, cysteine (Cys) is recognized not only as an important biomarker of various biological processes but also widely used as a significant additive in the food industry. However, the exact role that Cys plays in ERS has not been well answered up to now. In this paper, we reported the first flavone-based fluorescent probe (namely BFC) with nice endoplasmic reticulum (ER)-targeting ability, which was capable of monitoring Cys in a fast response (3.0 min), large stokes shift (130 nm) and low detection limit (10.4 nM). The recognition mechanism of Cys could be attributed to the addition-cyclization reaction involving a Cys residue and an acrylate group, resulting in the release of the strong excited-state intramolecular proton transfer (ESIPT) emission molecule of benzoflavonol (BF). The low cytotoxicity and good biocompatibility of the probe BFC allowed for monitoring the fluctuation of endogenous Cys levels under both ERS and OS processes, as well as in zebrafish models of epilepsy. Quantitative determination of Cys with the probe BFC was also achieved in three different food samples. Additionally, a probe-immersed test strips integrated with a smartphone device was successfully constructed for on-site colorimetric detection of Cys. Undoubtedly, our work provided a valuable tool for tracking Cys levels in both an epilepsy model and real food samples.


Assuntos
Cisteína , Retículo Endoplasmático , Epilepsia , Flavonas , Corantes Fluorescentes , Análise de Alimentos , Peixe-Zebra , Corantes Fluorescentes/química , Cisteína/análise , Animais , Epilepsia/diagnóstico , Flavonas/análise , Flavonas/química , Retículo Endoplasmático/metabolismo , Análise de Alimentos/métodos , Espectrometria de Fluorescência/métodos , Humanos , Modelos Animais de Doenças , Limite de Detecção , Estresse do Retículo Endoplasmático
4.
Food Chem ; 462: 140990, 2025 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-39208725

RESUMO

The frequent occurrence of food safety incidents has aroused public concern about food safety and key contaminants. Foodborne pathogen contamination, pesticide residues, heavy metal residues, and other food safety problems will significantly impact human health. Therefore, developing efficient and sensitive detection method to ensure food safety early warning is paramount. The aptamer-based sensor (aptasensor) is a novel analytical tool with strong targeting, high sensitivity, low cost, etc. It has been extensively utilized in the pharmaceutical industry, biomedicine, environmental engineering, food safety detection, and in other diverse fields. This work reviewed the latest research progress of aptasensors for food analysis and detection, mainly introducing their application in detecting various key food contaminants. Subsequently, the sensing mechanism and performance of aptasensors are discussed. Finally, the review will examine the challenges and opportunities related to aptasensors for detecting major contaminants in food, and advance implementation of aptasensors in food safety and detection.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Contaminação de Alimentos , Inocuidade dos Alimentos , Nanoestruturas , Contaminação de Alimentos/análise , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Nanoestruturas/química , Humanos , Análise de Alimentos/métodos , Análise de Alimentos/instrumentação
5.
Food Chem ; 462: 141026, 2025 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-39216373

RESUMO

Quantitative monitoring of the concentrations of epigallocatechin gallate (EGCG) and cysteine (Cys) is of great significance for promoting human health. In this study, iron/aluminum bimetallic MOF material MIL-53 (Fe, Al) was rapidly prepared under room temperature using a co-precipitation method, followed by investigating the peroxidase-like (POD-like) activity of MIL-53(Fe, Al) using 3,3',5,5'-tetramethylbenzidine (TMB) as a chromogenic substrate. The results showed that the Michaelis -Menten constants of TMB and H2O2 as substrates were 0.167 mM and 0.108 mM, respectively. A colorimetric sensing platform for detecting EGCG and Cys was developed and successfully applied for analysis and quantitative detection using a smartphone. The linear detection range for EGCG was 15∼80 µM (R2=0.994) and for Cys was 7∼95 µM (R2=0.998). The limits of detection (LOD) were 0.719 µM and 0.363 µM for EGCG and Cys, respectively. This work provides a new and cost-effective approach for the real-time analysis of catechins and amino acids.


Assuntos
Antioxidantes , Técnicas Biossensoriais , Catequina , Colorimetria , Smartphone , Colorimetria/métodos , Colorimetria/instrumentação , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Antioxidantes/análise , Antioxidantes/química , Catequina/análise , Catequina/análogos & derivados , Catequina/química , Cisteína/análise , Cisteína/análogos & derivados , Limite de Detecção , Análise de Alimentos/métodos , Análise de Alimentos/instrumentação
6.
Food Chem ; 462: 140962, 2025 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-39241683

RESUMO

Nitrite is a common ingredient in the industry and agriculture; it is everywhere, like water, food, and surroundings. Recently, several approaches have been developed to measure the nitrite levels. So, this review was presented as a summary of many approaches utilized to detect the nitrite. Furthermore, the types of information that may be acquired using these methodologies, including optic and electrical signals, were discussed. In electrical signal methods, electrochemical sensors are usually developed using different materials, including carbon, polymers, oxides, and hydroxides. At the same time, optic signals receiving techniques involve utilizing fluorescence chromatography, absorption, and spectrometry instruments. Furthermore, these methodologies' benefits, drawbacks, and restrictions are examined. Lastly, due to the efficiency and fast means of electrochemical detectors, it was suggested that they can be used for detecting nitrite in food safety. Futuristic advancements in the techniques used for nitrite determination are subsequently outlined.


Assuntos
Técnicas Eletroquímicas , Análise de Alimentos , Contaminação de Alimentos , Nitritos , Nitritos/análise , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Contaminação de Alimentos/análise , Análise de Alimentos/métodos , Análise de Alimentos/instrumentação
7.
Compr Rev Food Sci Food Saf ; 23(5): e13415, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39267152

RESUMO

The article explores the science and practice of electrospinning, tracing its history and examining the factors that influence fiber morphology, including the solution composition, processing conditions, and environmental conditions. It offers a thorough examination of electrospinning fundamentals geared toward generating an appropriate platform for creating tailored nanofibers for sensing applications in the food industry. These nanofibers play a critical role in food analysis, sensing, and traceability, and we highlight their effectiveness in identifying pesticide residues, food components, antibiotics, heavy metals, and foodborne pathogens as well as in monitoring the freshness and spoilage of food. The use of electrospinning technology is poised to make sensing platforms more accessible, affordable, and widespread, thereby significantly contributing to the improvement of food quality and safety monitoring practices.


Assuntos
Nanofibras , Nanofibras/química , Contaminação de Alimentos/análise , Contaminação de Alimentos/prevenção & controle , Análise de Alimentos/métodos
8.
Molecules ; 29(17)2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39274962

RESUMO

Teicoplanin has been banned in the veterinary field due to the drug resistance of antibiotics. However, teicoplanin residue from the antibiotic abuse of humans and animals poses a threat to people's health. Therefore, it is necessary to develop an efficient way for the highly accurate and reliable detection of teicoplanin from humans, food, and water. In this study, novel imprinted quantum dots of teicoplanin were prepared based on boronate affinity-based precisely controlled surface imprinting. The imprinting factor (IF) for teicoplanin was evaluated and reached a high value of 6.51. The results showed excellent sensitivity and selectivity towards teicoplanin. The relative fluorescence intensity was inversely proportional to the concentration of teicoplanin, in the range of 1.0-17 µM. And its limit of detection (LOD) was obtained as 0.714 µM. The fluorescence quenching process was mainly controlled by a static quenching mechanism via the non-radiative electron-transfer process between QDs and the five-membered cyclic boronate esters. The recoveries for the spiked urine, milk, and water samples ranged from 95.33 to 104.17%, 91.83 to 97.33, and 94.22 to 106.67%, respectively.


Assuntos
Antibacterianos , Ácidos Borônicos , Pontos Quânticos , Teicoplanina , Pontos Quânticos/química , Humanos , Teicoplanina/química , Teicoplanina/análise , Ácidos Borônicos/química , Antibacterianos/análise , Antibacterianos/química , Espectrometria de Fluorescência/métodos , Limite de Detecção , Água/química , Impressão Molecular/métodos , Ésteres/química , Ésteres/análise , Transporte de Elétrons , Contaminação de Alimentos/análise , Análise de Alimentos/métodos , Animais , Técnicas Biossensoriais/métodos , Leite/química , Fluorescência
9.
Anal Chim Acta ; 1325: 343120, 2024 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-39244306

RESUMO

The present study elucidates the effectiveness of a molecularly imprinted polyacrylonitrile-imbued graphite-base electrode (MAN@G) for the selective detection of folic acid (FA) in food samples. The prime objective of the recognition and quantification of vitamin compounds like FA is the overall quality assessment of vegetables and fruits. The cost-effective, reproducible, and durable MAN@G electrode has been fabricated using acrylonitrile (AN) as the monomer and FA as the template over graphite-base. The characterization of the synthesized MAN@G electrode material has been accomplished by utilizing UV-visible (UV-vis) spectroscopy and scanning electron microscopy (SEM). A tri-electrode system based on differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques was employed to explore the analytical performance of the synthesized electrode. Rigorous analyses divulged that a widespread linearity window could be exhibited by the electrode under an optimized experimental environment, ranging from 20 µM to 400 µM concentrations with an acceptable lower limit of detection (LOD) and limit of quantification (LOQ) of 18 nM, and 60 nM respectively. Additionally, this electrode exhibits high reproducibility, good stability, and high repeatability, with RSD values of 1.72 %, 1.32 %, and 1.19 %, respectively. The detection efficacy of the proposed electrode has been further examined in food extracts, namely orange, spinach, papaya, soybean, and cooked rice, which endorsed high accuracy compared to the high-performance liquid chromatography (HPLC) method. Moreover, the statistical results obtained from the t-test analysis were also satisfactory for the FA concentrations present in those five samples.


Assuntos
Resinas Acrílicas , Técnicas Eletroquímicas , Eletrodos , Ácido Fólico , Grafite , Grafite/química , Resinas Acrílicas/química , Ácido Fólico/análise , Impressão Molecular , Limite de Detecção , Análise de Alimentos/métodos , Polímeros Molecularmente Impressos/química , Frutas/química
10.
Mikrochim Acta ; 191(10): 576, 2024 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-39240389

RESUMO

Hydroquinone-based organic molecules are often used as unavoidable preservatives in the food industry. Among these additives, tertiary butylated hydroquinone (TBHQ) is widely employed as a preservative in various processed foods. However, the potential health risks associated with the excessive presence of TBHQ in food products have raised significant concerns. To address this pressing issuea novel binder-free composite composed of a manganese metal-organic framework and functionalized carbon nanofibers (Mn-MOF/f-CNF) has been developed as an electrode modifier for the ultrasensitive detection of TBHQ in food samples. The Mn-MOF/f-CNF composite was achieved using the ultrasonication method, revealing a lamellar sheet-like structure of the Mn-MOF and the curly thread-like fibrous structure of f-CNF. The developed Mn-MOF/f-CNF/SPE sensor system resulted in well-defined redox signals for TBHQ detection in a neutral pH solution. Compared to the unmodified SPE system, the modified system showed approximately a 300 mV reduction in overpotential and a twofold increase in peak current signal for TBHQ detection. The Mn-MOF/f-CNF/SPE sensor system showed a linear concentration window of 0.01 to 800 µM with a sensitivity of 6.28 µA µM-1 cm-2 and the obtained detection limit was 1.36 nM. Additionally, the proposed sensor displayed excellent reproducibility and repeatable results with an RSD of less than 5%. The real-time applicability of the Mn-MOF/f-CNF/SPE sensor system was demonstrated using real samples such as potato chips and instant noodles, showing excellent results with a recovery range of 95.1-98.5%.


Assuntos
Técnicas Eletroquímicas , Eletrodos , Hidroquinonas , Limite de Detecção , Manganês , Estruturas Metalorgânicas , Hidroquinonas/química , Hidroquinonas/análise , Estruturas Metalorgânicas/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Manganês/química , Contaminação de Alimentos/análise , Análise de Alimentos/métodos , Conservantes de Alimentos/análise , Conservantes de Alimentos/química
11.
Compr Rev Food Sci Food Saf ; 23(5): e70000, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39217507

RESUMO

Food processing unavoidably introduces various risky ingredients that threaten food safety. N-Nitrosamines (NAs) constitute a class of food contaminants, which are considered carcinogenic to humans. According to the compiled information, pretreatment methods based on solid-phase extraction (SPE) were widely used before the determination of volatile NAs in foods. The innovation of adsorbents and hybridization of other methods have been confirmed as the future trends of SPE-based pretreatment methods. Moreover, technologies based on liquid chromatography and gas chromatography were popularly applied for the detection of NAs. Recently, sensor-based methods have garnered increasing attention due to their efficiency and flexibility. More portable sensor-based technologies are recommended for on-site monitoring of NAs in the future. The application of artificial intelligence can facilitate data processing during high-throughput detection of NAs. Natural bioactive compounds have been confirmed to be effective in mitigating NAs in foods through antioxidation, scavenging precursors, and regulating microbial activities. Meanwhile, they exhibit strong protective activities against hepatic damage, pancreatic cancer, and other NA injuries. Further supplementation of data on the bioavailability of bioactives can be achieved through encapsulation and clinical trials. The utilization of bioinformatics tools rooted in various omics technologies is suggested for investigating novel mechanisms and finally broadening their applications in targeted therapies.


Assuntos
Contaminação de Alimentos , Nitrosaminas , Nitrosaminas/química , Contaminação de Alimentos/prevenção & controle , Contaminação de Alimentos/análise , Humanos , Inocuidade dos Alimentos/métodos , Extração em Fase Sólida/métodos , Análise de Alimentos/métodos
12.
Carbohydr Polym ; 344: 122533, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39218564

RESUMO

The increasing complexity and ubiquity of food processing and the emergence of fraudulent practices have made effective and reliable methods to authenticate food products of utmost importance. Carbohydrates, with various nutritional functions, are abundant in foods and can serve as potential markers for food authentication. However, the complex and diverse structures and properties of carbohydrates, especially polysaccharides, pose challenges. Nonetheless, significant progress has been made in this area. This paper provides an overview of the utilization of carbohydrates in food authentication since 2000, focusing on strategies involving carbohydrate-based markers, carbohydrate profiles, and carbohydrate-protein interaction-based assays. The analytical techniques, applications, challenges and limitations of these strategies are reviewed and discussed. The findings demonstrate that these strategies offer origin verification, quality assessment, adulteration detection, process control, and food species identification. Notably, oligosaccharide analysis has proven effective in food authentication and remains a promising marker, especially for analyzing intricate matrices. The advances in chromatography separation and mass spectrometry identification of isomers and trace amounts of these compounds have facilitated the discovery of such markers. In conclusion, carbohydrate analysis can play a crucial role in food authentication. Future research and development will make the authentication of carbohydrate-rich foods ever more accurate and efficient.


Assuntos
Carboidratos , Análise de Alimentos , Análise de Alimentos/métodos , Carboidratos/análise , Carboidratos/química , Contaminação de Alimentos/análise , Espectrometria de Massas/métodos , Humanos
13.
Anal Chim Acta ; 1328: 343181, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39266197

RESUMO

BACKGROUND: Antibiotic residues in food chain have raised concerns regarding their toxicity and involvement in antimicrobial resistance. However, most existing antibiotic biosensors are primarily applicable to liquid food samples. Given the complex matrix characteristics of foods, there is an urgent need for the development of effective antibiotic detection platforms that exhibit high universality and flexibility. Porous microneedles (PMN) are microdevice structures with needle-like shapes and microscale pores throughout their composition, which facilitate rapid sampling. Consequently, the integration of PMN with biosensors holds significant promise for the detection of antibiotic residues in complex food samples. RESULTS: In this study, hydrogel-forming PMN are fabricated by leveraging the oxygen-production capacity of thylakoid to generate bubbles and form porous structures. These PMN are then integrated with a fluorescence aptasensor for the quantification of the antibiotic netilmicin. The aptasensor consists of a netilmicin (NET) aptamer with stem loop and hairpin structure, which facilitated the binding of SYBR Green I to produce a fluorescent signal. In the presence of NET, the complete binding between NET and the aptamer results in a reduction of fluorescence intensity, thereby generating a detectable signal change for the detection of NET. Utilizing capillary action accelerate fluid extraction (2.9 times faster than nonporous microneedles) and a large specific surface area (5.1072 m2/g) conducive to aptasensor adsorb, the PMN achieve efficient capture and quantification of antibiotic with limits of detection and quantitation of 5.99 nM and 19.8 nM, respectively. SIGNIFICANCE: Porous microneedles with tunable porosity and desirable mechanical properties are successfully fabricated. The integration of PMN with aptasensor enable the efficient detection of netilmicin in fish, milk and river water samples, demonstrating high recovery rates. The PMN represent potential tools for the convenient and rapid detection of antibiotic residues within complex food matrices, thereby enhancing food safety monitoring.


Assuntos
Antibacterianos , Agulhas , Antibacterianos/análise , Porosidade , Tilacoides/química , Técnicas Biossensoriais , Aptâmeros de Nucleotídeos/química , Animais , Contaminação de Alimentos/análise , Resíduos de Drogas/análise , Limite de Detecção , Química Verde , Análise de Alimentos/métodos , Análise de Alimentos/instrumentação
14.
Sensors (Basel) ; 24(17)2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39275755

RESUMO

The most frequently used sulfonamide is sulfamethazine (SMZ) because it is often found in foods made from livestock, which is hazardous for individuals. Here, we have developed an easy, quick, selective, and sensitive analytical technique to efficiently detect SMZ. Recently, transition metal oxides have attracted many researchers for their excellent performance as a promising sensor for SMZ analysis because of their superior redox activity, electrocatalytic activity, electroactive sites, and electron transfer properties. Further, Cu-based oxides have a resilient electrical conductivity; however, to boost it to an extreme extent, a composite including two-dimensional (2D) graphitic carbon nitride (g-C3N4) nanosheets needs to be constructed and ready as a composite (denoted as g-C3N4/Cu2Y2O5). Moreover, several techniques, including X-ray diffraction analysis, scanning electron microscopy analysis, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy were employed to analyze the composites. The electrochemical measurements have revealed that the constructed g-C3N4/Cu2Y2O5 composites exhibit great electrochemical activity. Nevertheless, the sensor achieved outstanding repeatability and reproducibility alongside a low limit of detection (LOD) of 0.23 µM, a long linear range of 2 to 276 µM, and an electrode sensitivity of 8.86 µA µM-1 cm-2. Finally, the proposed GCE/g-C3N4/Cu2Y2O5 electrode proved highly effective for detection of SMZ in food samples, with acceptable recoveries. The GCE/g-C3N4/Cu2Y2O5 electrode has been successfully applied to SMZ detection in food and water samples.


Assuntos
Cobre , Técnicas Eletroquímicas , Análise de Alimentos , Grafite , Sulfametazina , Técnicas Eletroquímicas/métodos , Grafite/química , Sulfametazina/análise , Sulfametazina/química , Cobre/química , Cobre/análise , Análise de Alimentos/métodos , Compostos de Nitrogênio/química , Limite de Detecção , Eletrodos , Contaminação de Alimentos/análise , Água/química , Reprodutibilidade dos Testes
15.
Sci Rep ; 14(1): 21488, 2024 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-39277597

RESUMO

Graphite carbon nitride (g-C3N4) is a two-dimensional nano-sheet with electronic properties, which shows unique characteristics with high chemical and thermal stability in its structure. The functionalization of these compounds through covalent bonding is an important step towards significantly improving their properties and capabilities. To achieve this goal, a novel strategy for the covalent functionalization of Fe3O4@g-C3N4 with thiamine hydrochloride (vitamin B1) via cyanuric chloride (TCT), which is a divalent covalent linker, was presented. The efficiency of Fe3O4@gC3N4@Thiamine as a heterogeneous organic catalyst in the synthesis of spirooxindole-pyran derivatives and 2-amino-4H-pyran under solvent-free conditions was evaluated and the yields of high-purity products were presented. In addition, easy recycling and reuse for seven consecutive cycles without significant reduction in catalytic activity are other features of this catalyst. Moreover, the performance of the prepared sorbent in the microextraction technique (herein, magnetic solid phase extraction) was studied. The tebuconazole was selected as the target analyte. The target analyte was extracted and determined by HPLC-UV. Under the optimum condition, the linear range of the method (LDR) was estimated in the range of 0.2-100 µg L-1 (the coefficient of determination of 0.9962 for tebuconazole). The detection limit (LOD) of the method for tebuconazole was calculated to be 0.05 µg L-1. The limit of quantification (LOQ) of the method was also estimated to be 0.16 µg L-1. In order to check the precision of the proposed method, the intra-day and inter-day relative standard deviations (RSD%) were calculated, which were in the range of 1.5- 2.8%. The method was used for the successful extraction and determination of tebuconazole in tomato, cucumber, and carrot samples.


Assuntos
Grafite , Tiamina , Triazóis , Catálise , Triazóis/química , Triazóis/análise , Grafite/química , Tiamina/química , Tiamina/análise , Contaminação de Alimentos/análise , Análise de Alimentos/métodos , Compostos Heterocíclicos/química , Compostos Heterocíclicos/síntese química , Compostos de Nitrogênio/química , Microextração em Fase Sólida/métodos , Compostos Inorgânicos de Carbono/química
16.
Food Res Int ; 195: 114986, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39277248

RESUMO

The comprehensive determination of fatty acids without derivatization, including short-chain fatty acids (SCFAs), medium-chain fatty acids (MCFAs) and long-chain fatty acids (LCFAs), is a big challenge but powerful for lipidomics in biology, food, and environment. Herein, the dual mode unity solid-phase microextraction (DMU-SPME) combined with gas chromatography-flame ionization detector (GC-FID) or mass spectrometry (MS) was proposed as a powerful method for the determination of comprehensive free fatty acids in real samples. Under the optimized DMU-SPME conditions, the proposed method has good linearity (R2 ≥ 0.994) and low limits of determination (0.01-0.14 mg/L). In the stability analysis, the intra-day relative standard deviation was 1.39-12.43 %, and the inter-day relative standard deviation was 2.84-10.79 %. The recoveries of selected 10 fatty acids in real samples ranged from 90.18 % to 110.75 %, indicating that the method has good accuracy. Fatty acids ranging from C2 to C22 were detected in real samples by the untargeted determination method of DMU-SPME combined with gas chromatography-mass spectrometry (GC-MS). The DMU-SPME method proposed in this study can be used for lipid metabolism analysis and free fatty acid determination in the fields of biology, food, and environment.


Assuntos
Ácidos Graxos , Cromatografia Gasosa-Espectrometria de Massas , Microextração em Fase Sólida , Microextração em Fase Sólida/métodos , Ácidos Graxos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Ionização de Chama/métodos , Reprodutibilidade dos Testes , Animais , Análise de Alimentos/métodos , Cromatografia Gasosa/métodos , Ácidos Graxos não Esterificados/análise
17.
Talanta ; 280: 126753, 2024 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-39217712

RESUMO

Metamizole (MET) is an antipyretic and analgesic drug, the illegal use of which can result in residues of MET metabolites in edible tissues of animals. In this study, a computational chemistry-assisted hapten screening strategy was used to screen for the optimal immunogenic hapten-A and the optimal coating antigen hapten-G-OVA. A monoclonal antibody capable of recognizing two pharmacologically active metabolites of MET, 4-methylamidinoantipyrine (MAA) and 4-aminoantipyrine (AA), was prepared from the hapten-A. The antibody showed excellent specificity for MAA and AA and almost no cross-reactivity with the pharmacologically inactive metabolites 4-formamidinoantipyrine (FAA) and 4-acetamidinoantipyrine (AAA). An ic-ELISA was developed for the simultaneous detection of MAA and AA in animal-derived food, the limits of detection for MAA ranged from 0.93 to 1.18 µg/kg, while those for AA ranged from 1.74 to 4.61 µg/kg. The recovery rate fell within the range of 82 %-110 %, with a coefficient of variation less than 16.39 %.


Assuntos
Anticorpos Monoclonais , Dipirona , Haptenos , Haptenos/química , Haptenos/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/química , Animais , Dipirona/imunologia , Dipirona/análise , Dipirona/química , Camundongos , Contaminação de Alimentos/análise , Ensaio de Imunoadsorção Enzimática/métodos , Camundongos Endogâmicos BALB C , Análise de Alimentos/métodos
18.
Biosens Bioelectron ; 266: 116720, 2024 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-39241338

RESUMO

Quantification of trace amounts of proteins is technically challenging because proteins cannot be directly amplified like nucleic acids. To improve the analytical sensitivity and to complement conventional protein analysis methods, we developed a highly sensitive and homogeneous detection strategy called Protein-Induced DNA Dumbbell Amplification (PINDA). PINDA combines protein recognition with exponential nucleic acid amplification by using protein binding probes made of DNA strands conjugated to protein affinity ligands. When a pair of probes bind to the same target protein, complementary nucleic acid sequences that are conjugated to each probe are brought into close proximity. The increased local concentration of the probes results in the formation of a stable dumbbell structure of the nucleic acids. The DNA dumbbell is readily amplifiable exponentially using techniques such as loop-mediated isothermal amplification. The PINDA assay eliminates the need for washing or separation steps, and is suitable for on-site applications. Detection of the model protein, thrombin, has a linear range of 10 fM-100 pM and detection limit of 10 fM. The PINDA technique is successfully applied to the analysis of dairy samples for the detection of ß-lactoglobulin, a common food allergen, and Salmonella enteritidis, a foodborne pathogenic bacterium. The PINDA assay can be easily modified to detect other targets by changing the affinity ligands used to bind to the specific targets.


Assuntos
Técnicas Biossensoriais , DNA , Técnicas de Amplificação de Ácido Nucleico , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas Biossensoriais/métodos , DNA/química , DNA/genética , Salmonella enteritidis/isolamento & purificação , Salmonella enteritidis/genética , Trombina/análise , Limite de Detecção , Lactoglobulinas/análise , Lactoglobulinas/química , Contaminação de Alimentos/análise , Humanos , Animais , Análise de Alimentos/métodos , Leite/química , Leite/microbiologia , Microbiologia de Alimentos
19.
Sci Rep ; 14(1): 21144, 2024 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-39256396

RESUMO

Kojic acid (KA) has gained significant attention due to its widespread use in the food and cosmetics industries. However, concerns about its potential carcinogenic effects have heightened the need for sensitive detection methods. This study introduces a fluorescence-based optical sensor for the quantification of KA in food samples, utilizing fluorescent carbon dots (CDs) synthesized from pomegranate peel via a hydrothermal method. The Stern-Volmer plot demonstrated a linear response for KA in the range of 120 to 1200 µM, with a Pearson correlation coefficient (r) of 0.9999 and. The sensor exhibited a detection limit of 30 ± 0.04 µM and a limit of quantification (LOQ) of 90 ± 0.14 µM. Application of the developed method to soy sauce and vinegar samples yielded accurate KA determinations, with recoveries of 103.11 ± 0.96% and 104.45 ± 2.15%, respectively. These findings highlight the potential of the proposed sensor for practical applications in food quality and safety assessment, offering valuable insights into the presence of KA in food products.


Assuntos
Carbono , Análise de Alimentos , Punica granatum , Pironas , Pontos Quânticos , Punica granatum/química , Pironas/análise , Pironas/química , Carbono/química , Pontos Quânticos/química , Análise de Alimentos/métodos , Limite de Detecção , Corantes Fluorescentes/química , Contaminação de Alimentos/análise , Espectrometria de Fluorescência/métodos
20.
Food Res Int ; 194: 114873, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39232512

RESUMO

This study investigates the metabolome of high-quality hazelnuts (Corylus avellana L.) by applying untargeted and targeted metabolome profiling techniques to predict industrial quality. Utilizing comprehensive two-dimensional gas chromatography and liquid chromatography coupled with high-resolution mass spectrometry, the research characterizes the non-volatile (primary and specialized metabolites) and volatile metabolomes. Data fusion techniques, including low-level (LLDF) and mid-level (MLDF), are applied to enhance classification performance. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) reveal that geographical origin and postharvest practices significantly impact the specialized metabolome, while storage conditions and duration influence the volatilome. The study demonstrates that MLDF approaches, particularly supervised MLDF, outperform single-fraction analyses in predictive accuracy. Key findings include the identification of metabolites patterns causally correlated to hazelnut's quality attributes, of them aldehydes, alcohols, terpenes, and phenolic compounds as most informative. The integration of multiple analytical platforms and data fusion methods shows promise in refining quality assessments and optimizing storage and processing conditions for the food industry.


Assuntos
Corylus , Metaboloma , Metabolômica , Análise de Componente Principal , Corylus/química , Metabolômica/métodos , Inteligência Artificial , Análise dos Mínimos Quadrados , Análise Discriminante , Qualidade dos Alimentos , Nozes/química , Análise de Alimentos/métodos , Compostos Orgânicos Voláteis/análise
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