RESUMEN

The fraudulent adulteration of goat milk with cheaper and more available milk of other species such as cow milk is occurrence. The aims of the present study were to investigate the effect of goat milk adulteration with cow milk on the mid-infrared (MIR) spectrum and further evaluate the potential of MIR spectroscopy to identify and quantify the goat milk adulterated. Goat milk was adulterated with cow milk at 5 different levels including 10%, 20%, 30%, 40%, and 50%. Statistical analysis showed that the adulteration had significant effect on the majority of the spectral wavenumbers. Then, the spectrum was preprocessed with standard normal variate (SNV), multiplicative scattering correction (MSC), Savitzky-Golay smoothing (SG), SG plus SNV, and SG plus MSC, and partial least squares discriminant analysis (PLS-DA) and partial least squares regression (PLSR) were used to establish classification and regression models, respectively. PLS-DA models obtained good results with all the sensitivity and specificity over 0.96 in the cross-validation set. Regression models using raw spectrum obtained the best result, with coefficient of determination (R2), root mean square error (RMSE), and the ratio of performance to deviation (RPD) of cross-validation set were 0.98, 2.01, and 8.49, respectively. The results preliminarily indicate that the MIR spectroscopy is an effective technique to detect the goat milk adulteration with cow milk. In future, milk samples from different origins and different breeds of goats and cows should be collected, and more sophisticated adulteration at low levels should be further studied to explore the potential and effectiveness of milk mid-infrared spectroscopy and chemometrics.

Asunto(s)

Contaminación de Alimentos , Cabras , Leche , Espectrofotometría Infrarroja , Animales , Leche/química , Análisis de los Mínimos Cuadrados , Contaminación de Alimentos/análisis , Espectrofotometría Infrarroja/métodos , Análisis Discriminante , Bovinos , Quimiometría/métodos

RESUMEN

AFB1 is a harmful substance that can be found in agricultural products and can seriously affect human health, even in trace amounts. Therefore, monitoring AFB1 levels to ensure food safety and protect public health is crucial. New, highly reliable, selective, and rapid detection methods are needed to achieve this goal. Our work involves the development of a polymeric membrane sensor using radical polymerization that can accurately detect AFB1. Various spectroscopic techniques (Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM)) were used to obtain information about the structural and morphological properties of the prepared sensor. The sensor displayed fluorescence selectively responsive to AFB1 at the excitation wavelength of 376 nm and emission wavelength of 423 nm. The polymeric fluorescence sensor showed good sensitivity and a wide linear range from 9.61 × 10-10 and 9.61 × 10-9 mol/L for AFB1quantification. The limit of detection (LOD) is as low as 3.84 × 10-10 mol/L for AFB1. Other mycotoxins, such as aflatoxin B2 and aflatoxin G1, did not interfere with the sensor's high selectivity towards AFB1. To test the sensor's effectiveness in detecting AFB1 in real samples, three different grain samples - peanuts, hazelnut butter, and peanuts with a sauce known to contain AFB1 - were utilized. The results were satisfactory and demonstrated that the sensor can be successfully employed in real samples, with an error range of 0.43 % to 12.10 %.

Asunto(s)

Aflatoxina B1 , Límite de Detección , Espectrometría de Fluorescencia , beta-Ciclodextrinas , Aflatoxina B1/análisis , Espectrometría de Fluorescencia/métodos , beta-Ciclodextrinas/química , Espectroscopía Infrarroja por Transformada de Fourier , Contaminación de Alimentos/análisis , Grano Comestible/química , Polímeros/química

RESUMEN

The contamination of mycotoxins poses a serious threat to global food security, hence the urgent need for simultaneous detection of multiple mycotoxins. Herein, two SERS nanoprobes were synthesized by embedded SERS tags (4-mercaptopyridine, 4MPy; 4-mercaptobenzonitrile, TBN) into the Au and Ag core-shell structure, and each was coupled with the aptamers specific to ochratoxin A (OTA) and zearalenone (ZEN). Meanwhile, a rigid enhanced substrate Indium tin oxide glass/AuNPs/Graphene oxide (ITO/AuNPs/GO) was combined with aptamer functionalized Au@AgNPs via π-π stacking interactions between the aptamer and GO to construct a surface-enhanced Raman spectroscopy (SERS) aptasensor, thereby inducing a SERS enhancement effect for the effective and swift simultaneous detection of both OTA and ZEN. The presence of OTA and ZEN caused signal probes dissociation, resulting in an inverse correlation between Raman signal intensity (1005 cm-1 and 2227 cm-1) and the concentrations of OTA and ZEN, respectively. The SERS aptasensor exhibited wide linear detection ranges of 0.001-20 ng/mL for OTA and 0.1-100 ng/mL for ZEN, with low detection limits (LOD) of 0.94 pg/mL for OTA and 59 pg/mL for ZEN. Furthermore, the developed SERS aptasensor demonstrated feasible applicability in the detection of OTA and ZEN in maize, showcasing its substantial potential for practical implementation.

Asunto(s)

Aptámeros de Nucleótidos , Oro , Grafito , Límite de Detección , Nanopartículas del Metal , Ocratoxinas , Plata , Espectrometría Raman , Zearalenona , Ocratoxinas/análisis , Espectrometría Raman/métodos , Oro/química , Zearalenona/análisis , Nanopartículas del Metal/química , Aptámeros de Nucleótidos/química , Plata/química , Grafito/química , Compuestos de Estaño/química , Técnicas Biosensibles/métodos , Contaminación de Alimentos/análisis

RESUMEN

Polylactic acid (PLA) straws hold eco-friendly potential; however, residual diisocyanates used to enhance the mechanical strength can generate carcinogenic primary aromatic amines (PAAs), posing health risks. Herein, we present a rapid, comprehensive strategy to detecting PAAs in 18 brands of food-grade PLA straws and assessing their migration into diverse food simulants. Surface-enhanced Raman spectroscopy was conducted to rapidly screen straws for PAAs. Subsequently, qualitative determination of migrating PAAs into various food simulants (4 % acetic acid, 10 % ethanol, 50 % ethanol) occurred at 70 °C for 2 h using liquid chromatography-mass spectrometry. Three PAAs including 4,4'-methylenedianiline, 2,4'-methylenedianiline, and 2,4-diaminotoluene were detected in all straws. Specifically, 2,4-diaminotoluene in 50 % ethanol exceeded specific migration limit of 2 µg/kg, raising safety concerns. Notably, PAAs migration to 10 % and 50 % ethanol surpassed that to 4 % acetic acid within a short 2-hour period. Moreover, PLA straws underwent varying degrees of shape changes before and after migration. Straws with poly(butylene succinate) resisted deformation compared to those without, indicating enhanced heat resistance, while poly(butyleneadipate-co-terephthalate) improved hydrolysis resistance. Importantly, swelling study unveiled swelling effect wasn't the primary factor contributing to the increased PAAs migration in ethanol food simulant, as there was no significant disparity in swelling degrees across different food simulants. FT-IR and DSC analysis revealed higher PAAs content in 50 % ethanol were due to highly concentrated polar ethanol disrupting hydrogen bonds and van der Waal forces holding PLA molecules together. Overall, minimizing contact between PLA straws and alcoholic foods is crucial to avoid potential safety risks posed by PAAs.

Asunto(s)

Aminas , Poliésteres , Espectrometría Raman , Poliésteres/química , Espectrometría Raman/métodos , Cromatografía Liquida/métodos , Aminas/análisis , Aminas/química , Espectrometría de Masas/métodos , Contaminación de Alimentos/análisis , Embalaje de Alimentos , Cromatografía Líquida con Espectrometría de Masas

RESUMEN

Perilla leaf oil (PLO) is a global premium vegetable oil with abundant nutrients and substantial economic value, rendering it susceptible to potential adulteration by unscrupulous entrepreneurs. The addition of cinnamon oil (CO) is one of the main adulteration avenues for illegal PLOs. In this study, new and real-time ambient mass spectrometric methods were developed to detect CO adulteration in PLO. First, atmospheric solids analysis probe tandem mass spectrometry combined with principal component analysis and principal component analysis-linear discriminant analysis was employed to differentiate between authentic and adulterated PLO. Then, a spectral library was established for the instantaneous matching of cinnamaldehyde in the samples. Finally, the results were verified using the SRM mode of ASAP-MS/MS. Within 3 min, the three methods successfully identified CO adulteration in PLO at concentrations as low as 5% v/v with 100% accuracy. The proposed strategy was successfully applied to the fraud detection of CO in PLO.

Asunto(s)

Cinnamomum zeylanicum , Contaminación de Alimentos , Hojas de la Planta , Aceites de Plantas , Contaminación de Alimentos/análisis , Aceites de Plantas/química , Aceites de Plantas/análisis , Hojas de la Planta/química , Cinnamomum zeylanicum/química , Perilla/química , Espectrometría de Masas en Tándem/métodos , Espectrometría de Masas/métodos

RESUMEN

The underlying toxicity mechanisms of microplastics on oysters have rarely been explored. To fill this gap, the present study investigated the metabolic profile and protein expression responses of oysters to microplastic stress through metabolomics and biochemical analyses. Oysters were exposed to microplastics for 21 days, and the results indicated that the microplastics induced oxidative stress, with a significant decrease in SOD activity in the 0.1 mg/L exposure group. Metabolomics revealed that exposure to microplastics disturbed many metabolic pathways, such as amino acid metabolism, lipid metabolism, biosynthesis of amino acids, aminoacyl-tRNA biosynthesis, and that different concentrations of microplastics induced diverse metabolomic profiles in oysters. Overall, the current study provides new reference data and insights for assessing food safety and consumer health risks caused by microplastic contamination.

Asunto(s)

Crassostrea , Microplásticos , Estrés Oxidativo , Poliestirenos , Contaminantes Químicos del Agua , Animales , Crassostrea/metabolismo , Crassostrea/efectos de los fármacos , Crassostrea/química , Microplásticos/metabolismo , Contaminantes Químicos del Agua/metabolismo , Estrés Oxidativo/efectos de los fármacos , Poliestirenos/química , Poliestirenos/metabolismo , Metaboloma/efectos de los fármacos , Mariscos/análisis , Metabolómica , Contaminación de Alimentos/análisis

RESUMEN

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.

Asunto(s)

Aptámeros de Nucleótidos , Técnicas Biosensibles , Contaminación de Alimentos , Inocuidad de los Alimentos , Nanoestructuras , Contaminación de Alimentos/análisis , Aptámeros de Nucleótidos/química , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Nanoestructuras/química , Humanos , Análisis de los Alimentos/métodos , Análisis de los Alimentos/instrumentación

RESUMEN

A rapid photoelectrochemical (PEC) sensor was constructed for nitrite detection in food based on the one-step chemical etching strategy of BiOCl/Zn0.5Cd0.5S (BOC/ZCS) nanocomposites by nitrite. BOC/ZCS heterojunction was prepared by a simple coprecipitation method, and it was found that BOC/ZCS showed significant photoelectrochemical (PEC) activity. The results of this study confirmed that the decrease in the photocurrent of the sensor was linked to the etching of ZCS by nitrite under acidic conditions. Under optimized conditions, the BOC/ZCS-based PEC sensor showed good analytical properties for detecting nitrite, with linear ranges of 1-100 µM and 100-600 µM. The detection limit of the sensor was 0.41 µM (S/N = 3). Excellent repeatability, reproducibility, low background noise, and immunity to interference were demonstrated using the proposed system, and satisfactory results were achieved for the nitrite assay using real samples. These results demonstrate a new method for nitrite detection developed using the proposed PEC sensor.

Asunto(s)

Técnicas Electroquímicas , Límite de Detección , Nitritos , Nitritos/análisis , Técnicas Electroquímicas/instrumentación , Bismuto/química , Zinc/química , Zinc/análisis , Nanocompuestos/química , Procesos Fotoquímicos , Contaminación de Alimentos/análisis

RESUMEN

To improve the adsorption affinity and selectivity of fipronils (FPNs), including fipronil, its metabolites and analogs, a magnetic covalent organic framework (Fe3O4@COF-F) with copious fluorine affinity sites was innovatively designed as an adsorbent of magnetic solid-phase extraction (MSPE). The enhanced surface area, pore size, crystallinity of Fe3O4@COF-F and its exponential adsorption capacities (187.3-231.5 mg g-1) towards fipronils were investigated. Combining MSPE with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), an analytical method was established for the selective determination of fipronils in milk and milk powder samples. This method achieved high sensitivity (LODs: 0.004-0.075 ng g-1), satisfactory repeatability and accuracy with spiked recoveries ranging from 89.9% to 100.3% (RSDs≤5.1%). Overall, the constructed Fe3O4@COF-F displayed great potential for the selective enrichment of fipronils, which could be ascribed to fluorine­fluorine interaction. This method proposed a feasible and promising strategy for the development of functionalized COF and broadened its application in fluorine containing hazards detection.

Asunto(s)

Flúor , Contaminación de Alimentos , Estructuras Metalorgánicas , Leche , Pirazoles , Extracción en Fase Sólida , Espectrometría de Masas en Tándem , Pirazoles/química , Contaminación de Alimentos/análisis , Flúor/química , Leche/química , Animales , Estructuras Metalorgánicas/química , Adsorción , Cromatografía Líquida de Alta Presión , Insecticidas/química , Insecticidas/análisis , Límite de Detección

RESUMEN

Excess nitrites are potentially threatening to human health, so it is urgent to develop accurate and sensitive methods. The development of sensors can provide early warning of possible hazards and alert people to protect public health. This work presents an NiSx@MoS2-composite with excellent electrochemical activity, representing a key finding for highly sensitive NO2- detection and sensor development. With the assistance of NiSx@MoS2, this electrochemical sensor has excellent quantitative detection performance. It has a wide detection range (0.0001-0.0020 mg/mL) and a low detection limit (1.863*10-5 mg/mL) for NO2-. This electrochemical sensor maintains excellent specificity among numerous interferences, and it completes the accurate detection of different real food samples. Pleasingly, the electrochemical sensor has satisfactory repeatability stability, and potential for practical applications. It would demonstrate tremendous potential in scientific dietary guidance, food safety detection and other fields.

Asunto(s)

Disulfuros , Técnicas Electroquímicas , Límite de Detección , Molibdeno , Molibdeno/química , Técnicas Electroquímicas/instrumentación , Disulfuros/química , Nitritos/análisis , Contaminación de Alimentos/análisis

RESUMEN

Phoxim, extensively utilized in agriculture as an organothiophosphate insecticide, has the potential to cause neurotoxicity and pose human health hazards. In this study, an electrochemical enzyme biosensor based on Ti3C2 MXene/MoS2@AuNPs/AChE was constructed for the sensitive detection of phoxim. The two-dimensional multilayer structure of Ti3C2 MXene provides a robust framework for MoS2, leading to an expansion of the specific surface area and effectively preventing re-stacking of Ti3C2 MXene. Additionally, the synergistic effect of self-reduced grown AuNPs with MoS2 further improves the electrical conductivity of the composites, while the robust framework provides a favorable microenvironment for immobilization of enzyme molecules. Ti3C2 MXene/MoS2@AuNPs electrochemical enzyme sensor showed a significant response to phoxim in the range of 1 × 10-13 M to 1 × 10-7 M with a detection limit of 5.29 × 10-15 M. Moreover, the sensor demonstrated excellent repeatability, reproducibility, and stability, thereby showing its promising potential for real sample detection.

Asunto(s)

Técnicas Biosensibles , Técnicas Electroquímicas , Frutas , Oro , Nanopartículas del Metal , Nanocompuestos , Compuestos Organotiofosforados , Titanio , Oro/química , Técnicas Electroquímicas/instrumentación , Técnicas Electroquímicas/métodos , Nanocompuestos/química , Frutas/química , Nanopartículas del Metal/química , Técnicas Biosensibles/instrumentación , Compuestos Organotiofosforados/análisis , Titanio/química , Límite de Detección , Contaminación de Alimentos/análisis , Molibdeno/química , Insecticidas/análisis , Insecticidas/química , Residuos de Plaguicidas/análisis , Residuos de Plaguicidas/química

RESUMEN

In this study, we focused on the successful construction of [(4,4'-bipy/P2Mo17Co)6] modified electrodes using the layer-by-layer assembly method for the sensitive detection of sulfathiazole (ST). The redox reaction between ST and the metal ions in the modified layer leads to the transfer of electrons, resulting in the generation of the electrical signal. The introduction of 4,4'-bipyridine (4,4'-bipy) enhanced the molecular recognition of ST by the modified electrode. Under the combined effect of P2Mo17Co and 4,4'-bipy, the sensor exhibited good performance for ST detection (LOD: 0.5616 µM, linear ST concentration range: 0-50 µM). The spiked recoveries of the two groups were 84.4%-103.2% and 90.9%-109.4% for the determination of ST residues in large yellow croaker and South American white shrimp, respectively. In addition, the electrode showed excellent performance in terms of stability, reproducibility, and anti-interference ability.

Asunto(s)

Técnicas Electroquímicas , Electrodos , Sulfatiazol , Técnicas Electroquímicas/instrumentación , Animales , Sulfatiazol/química , Contaminación de Alimentos/análisis , Sulfatiazoles/química , Sulfatiazoles/análisis , Límite de Detección , Penaeidae/química , Oxidación-Reducción

RESUMEN

Cadmium (Cd) in rice is a significant concern for its quality and safety. Currently, there is a crucial need to develop cost-effective and efficient ways to remove Cd or re-utilize Cd-contaminated rice. The food additive sodium erythorbate is produced via 2-ketogluconic acid (2KGA) fermentation by Pseudomonas plecoglossicida and lactonization using starch-rich raw materials, such as rice. We aimed to determine whether cadmium-contaminated rice can be used to produce sodium erythorbate. To achieve this aim, the migration of cadmium during the production of sodium erythorbate from Cd-contaminated rice was studied. Five rice varieties with different Cd contents from 0.10 to 0.68 mg/kg were used as raw materials. The results indicated the presence of Cd in rice and CaCO3 did not have a notable impact on the fermentation performance of 2KGA. The acidification of 2KGA fermentation broth, the addition of K4Fe(CN)6·3H2O and ZnSO4, and 2KGA purification using cation exchange effectively removed >98% of the Cd in the fermentation broth, but the 2KGA yield remained high at approximately 94%. The sodium erythorbate synthesized from Cd-contaminated rice was of high quality and free from Cd, meeting the requirements of the Chinese National Standard, GB 1886.28-2016. The study provided a safe and effective strategy for comprehensively utilizing Cd-contaminated rice to produce high value-added food additive.

Asunto(s)

Cadmio , Fermentación , Aditivos Alimentarios , Contaminación de Alimentos , Oryza , Oryza/química , Oryza/metabolismo , Oryza/microbiología , Cadmio/metabolismo , Cadmio/análisis , Contaminación de Alimentos/análisis , Aditivos Alimentarios/análisis , Aditivos Alimentarios/metabolismo , Pseudomonas/metabolismo , Azúcares Ácidos/metabolismo , Azúcares Ácidos/química , Azúcares Ácidos/análisis

RESUMEN

Chemicals from packaging materials might be transferred into food resulting in consumer exposure. Identifying these migrated chemicals is highly challenging and crucial to perform their safety assessment, usually starting by the understanding of the chemical composition of the packaging material itself. This study explores the use of the Molecular Networking (MN) approach to support identification of the extracted chemicals. Two formulations of bioplastics were analyzed using Liquid Chromatography hyphenated to High-Resolution Mass Spectrometry. Data processing and interpretation using a conventional manual method was performed as a point of comparison to understand the power of MN. Interestingly, only the MN approach facilitated the identification of unknown chemicals belonging to a novel oligomer series containing the azelaic acid monomer. The MN approach provided a faster visualization of chemical families in addition to the highlight of unrelated chemicals enabling to prioritize chemicals for further investigation improving the safety assessment of packaging materials.

Asunto(s)

Embalaje de Alimentos , Embalaje de Alimentos/instrumentación , Contaminación de Alimentos/análisis , Espectrometría de Masas , Cromatografía Líquida de Alta Presión

RESUMEN

Integrating multiple functionalities into a single entity is highly important, especially when a broad spectrum of application is required. In the present work, we synthesized a novel manganese-based MOF (denoted as UoZ-6) that functions as a cold/hot-adapted and recyclable oxidase nanozyme (Km 0.085 mM) further developed for ratiometric-based colorimetric and color tonality visual-mode detection of nitrite in water and food. Nitrite ions promote the diazotization process of the oxTMB product, resulting in a decay in the absorbance signal at 652 nm and the emergence of a new signal at 461 nm. The dual-absorbance ratiometric platform for nitrite ion detection functions effectively across a wide temperature range (0 °C to 100 °C), offering a linear detection range of 5-45 µM with a detection limit of 0.15 µM using visual-mode. This approach is sensitive, reliable, and selective, making it effective for detecting nitrite ions in processed meat and water.

Asunto(s)

Colorimetría , Nitritos , Nitritos/análisis , Colorimetría/métodos , Estructuras Metalorgánicas/química , Oxidorreductasas/química , Oxidorreductasas/metabolismo , Límite de Detección , Frío , Calor , Contaminación de Alimentos/análisis , Color

RESUMEN

This study presents a low-cost smartphone-based imaging technique called smartphone video imaging (SVI) to capture short videos of samples that are illuminated by a colour-changing screen. Assisted by artificial intelligence, the study develops new capabilities to make SVI a versatile imaging technique such as the hyperspectral imaging (HSI). SVI enables classification of samples with heterogeneous contents, spatial representation of analyte contents and reconstruction of hyperspectral images from videos. When integrated with a residual neural network, SVI outperforms traditional computer vision methods for ginseng classification. Moreover, the technique effectively maps the spatial distribution of saffron purity in powder mixtures with predictive performance that is comparable to that of HSI. In addition, SVI combined with the U-Net deep learning module can produce high-quality images that closely resemble the target images acquired by HSI. These results suggest that SVI can serve as a consumer-oriented solution for food authentication.

Asunto(s)

Teléfono Inteligente , Imágenes Hiperespectrales/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Contaminación de Alimentos/análisis , Grabación en Video , Análisis de los Alimentos

RESUMEN

A modified QuEChERS method was developed to determine multi-class pesticide and veterinary residues in aquatic products. Chitosan microspheres were conveniently synthesized and utilized as the cleanup adsorbent in the QuEChERS procedure, showcasing rapid filtration one-step pretreatment ability for the determination of drug multi-residues in aquatic products. Compared to conventional synthetic sorbents, chitosan microspheres not only have good purification performance, but also have renewable and degradable properties. This novel sorbent worked well in the simultaneous determination of 95 pesticides and veterinary drug residues in aquatic products after being combined with an improved one-step vortex oscillating cleanup method. We achieved recoveries ranging from 64.0% to 115.9% for target drugs in shrimp and fish matrix. The limits of detection and quantification were 0.5-1.0 and 1.0-2.0 µg kg-1, respectively. Notably, hydrocortisone was detected with considerable frequency and concentration in the tested samples, underscoring the necessity for stringent monitoring of this compound in aquatic products.

Asunto(s)

Quitosano , Peces , Microesferas , Espectrometría de Masas en Tándem , Drogas Veterinarias , Animales , Quitosano/química , Cromatografía Líquida de Alta Presión , Drogas Veterinarias/análisis , Drogas Veterinarias/aislamiento & purificación , Contaminación de Alimentos/análisis , Residuos de Medicamentos/análisis , Residuos de Medicamentos/aislamiento & purificación , Residuos de Medicamentos/química , Plaguicidas/aislamiento & purificación , Plaguicidas/análisis , Plaguicidas/química , Residuos de Plaguicidas/aislamiento & purificación , Residuos de Plaguicidas/análisis , Residuos de Plaguicidas/química , Adsorción , Extracción en Fase Sólida/métodos , Extracción en Fase Sólida/instrumentación , Contaminantes Químicos del Agua/aislamiento & purificación , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/análisis , Alimentos Marinos/análisis , Mariscos/análisis , Cromatografía Líquida con Espectrometría de Masas

RESUMEN

Rapid screening for foodborne pathogens is crucial for food safety. A rapid and one-step electrochemical sensor has been developed for the detection of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Salmonella typhimurium (S. typhimurium). Through the construction of aptamer/two-dimensional carboxylated Ti3C2Tx (2D C-Ti3C2Tx)/two-dimensional Zn-MOF (2D Zn-MOF) composites, the recognition elements, signal tags, and signal amplifiers are integrated on the electrode surface. Pathogens are selectively captured using the aptamer, which increases the impedance of the electrode surface，leads to a decrease in the 2D Zn-MOF current. Bacteria can be rapidly quantified using a one-step detection method and the replacement of aptamers. The detection limits for E. coli, S. aureus, and S. typhimurium are 6, 5, and 5 CFU·mL-1, respectively. The sensor demonstrated reliable detection capabilities in real-sample testing. Therefore, the one-step sensor based on the 2D Zn-MOF and 2D C-Ti3C2Tx has significant application value in the detection of foodborne pathogens.

Asunto(s)

Técnicas Electroquímicas , Escherichia coli , Salmonella typhimurium , Staphylococcus aureus , Zinc , Staphylococcus aureus/aislamiento & purificación , Salmonella typhimurium/aislamiento & purificación , Zinc/análisis , Escherichia coli/aislamiento & purificación , Técnicas Electroquímicas/instrumentación , Técnicas Biosensibles/instrumentación , Estructuras Metalorgánicas/química , Microbiología de Alimentos , Titanio/química , Límite de Detección , Electrodos , Contaminación de Alimentos/análisis

RESUMEN

The 3,3',5,5'-tetramethylbenzidine-H2O2 (TMB-H2O2) platform has gained widespread use for rapid detection of various analytes in foods. However, the existing TMB-H2O2 platforms suffer from limited accuracy, as their signal output is confined to the visible region, which is prone to interference from various food colorants in real samples. To address this challenge, a novel Au@Os-mediated TMB-H2O2 platform is developed for both rapid and accurate detection of analytes in foods. The prepared Au@Os NPs exhibit remarkable peroxidase-like activity, making the platform display dual absorption peaks in visible and near-infrared (NIR) regions, respectively. This Au@Os-mediated TMB-H2O2 platform exhibited three linear ranges across different concentrations of ziram from 1-100, 150-600, and 800-2000 nM with limit of detection (LOD) 7.9 nM and limit of quantification (LOQ) 24.15 nM respectively. Further, the Au@Os-mediated TMB-H2O2 platform was also used for rapid and accurate detection of ziram in real food samples like apple, tomato, and black tea.

Asunto(s)

Contaminación de Alimentos , Oro , Peróxido de Hidrógeno , Límite de Detección , Peróxido de Hidrógeno/química , Peróxido de Hidrógeno/análisis , Oro/química , Contaminación de Alimentos/análisis , Bencidinas/química , Malus/química , Solanum lycopersicum/química , Té/química , Nanopartículas del Metal/química , Colorantes de Alimentos/análisis

RESUMEN

In this study, covalent organic frameworks (COFs) were grown in situ on magnetic nitrogen-doped graphene foam (MNGF), and the resulting composite of COFs-modified MNGF (MNC) was wrapped by molecularly imprinted polymers (MNC@MIPs) for specifically capturing SAs. A magnetic solid phase extraction (MSPE) method for SAs was established using MNC@MIPs with good magnetic responsiveness. The adsorption performance of MNC@MIPs was superior to that of non-molecularly imprinted polymers (MNC@NIPs), with shorter adsorption/desorption time and higher imprinting factors. A high-efficiency SAs analytical method was developed by fusing HPLC and MNC@MIPs-based MSPE. This approach provides excellent precision, a low detection limit, and wide linearity. By analyzing fish samples, the feasibility of the approach was confirmed, with SAs recoveries and relative standard deviations in spiked samples in the ranges of 77.2-112.7 % and 2.0-7.2 %, respectively. This study demonstrated the potential use of MNC@MIPs-based MSPE for efficient extraction and quantitation of trace hazards in food.

Asunto(s)

Peces , Contaminación de Alimentos , Estructuras Metalorgánicas , Polímeros Impresos Molecularmente , Extracción en Fase Sólida , Sulfonamidas , Extracción en Fase Sólida/métodos , Extracción en Fase Sólida/instrumentación , Animales , Polímeros Impresos Molecularmente/química , Adsorción , Contaminación de Alimentos/análisis , Estructuras Metalorgánicas/química , Sulfonamidas/aislamiento & purificación , Sulfonamidas/química , Sulfonamidas/análisis , Impresión Molecular , Polímeros/química