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1.
Medicine (Baltimore) ; 103(28): e38909, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38996146

RESUMO

To compare the differences in clinical and morphological features between small ruptured intracranial aneurysms and large unruptured intracranial aneurysms to evaluate the risk factors for the rupture of IAs. The clinical data of 189 consecutive patients with 193 IAs were reviewed. The patients and IAs were divided into ruptured (<5 mm) and unruptured groups (>10 mm). The characteristics of the patients and the intracranial aneurysms (IAs) were compared between the 2 groups, and the risk factors for rupture of IAs were assessed using multiple logistic regression. Patient age (odds ratio [OR], 0.955), IA located at the internal carotid artery (ICA, OR, 0.202), irregular shape (OR, 0.083) and parent vessel diameter (OR, 0.426) were negatively correlated with the risk of IA rupture. IAs located at bifurcations (OR, 6.766) were positively correlated with the risk of IA rupture. In addition to the size of the IAs, regardless of IAs shape, other factors, such as younger age (<63.5 years), location at a bifurcation, IAs located at the ICA and a small parent vessel diameter (<3.25 mm), can influence the risk of IA rupture.


Assuntos
Aneurisma Roto , Aneurisma Intracraniano , Humanos , Aneurisma Intracraniano/epidemiologia , Aneurisma Intracraniano/patologia , Aneurisma Intracraniano/complicações , Masculino , Feminino , Pessoa de Meia-Idade , Fatores de Risco , Idoso , Estudos Retrospectivos , Adulto , Fatores Etários , Artéria Carótida Interna/patologia , Modelos Logísticos
2.
J Hazard Mater ; 476: 135112, 2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38981234

RESUMO

In light of the significant risks that mycotoxins posed to public health and environmental safety, this research developed an adsorbent MIPs/Apt/AuNPs@ZIF-67 (MA-AZ) utilizing a dual-recognition approach combining molecularly imprinted polymers (MIPs) and aptamer (Apt). This innovative method enabled the effective and highly selective recognition and enrichment of ochratoxin A (OTA). ZIF-67 was utilized as a carrier with a substantial specific surface area, and gold nanoparticles (AuNPs) were loaded on its surface to fix the thiol-modified Apt on the surface of the carrier. Then, an initiator was used to initiate a polymerization reaction, and the generated MIPs coated Apt/AuNPs@ZIF-67, thereby synthesizing the MA-AZ with a "synergistic recognition" effect. The Apt significantly increased the number of recognition sites within the imprinted cavities, and MIPs played roles in identifying targets, fixing and protecting Apt. The combination of the both produced the effect of "1+1>2". The study on the adsorption performance of MA-AZ found that the adsorption capacity of MA-AZ could reach 65.1 mg/g, and the imprinted factor was 5.48. In addition, MA-AZ exhibited excellent stability, specificity, reusability and recovery rate. Thus, this study offers valuable insights for the recognition and enrichment of hazardous substances, and helps to promote the rapid development of safety detection.

3.
Front Microbiol ; 15: 1367630, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38952444

RESUMO

Purpose: To investigate the therapeutic efficiency of a novel drink termed "Ferment" in cases of ulcerative colitis (UC) and its influence on the gut microbiota. Method: In this study, we developed a complex of mixed fruit juice and lactic acid bacteria referred to as Ferment. Ferment was fed to mice for 35 days, before inducing UC with Dextran Sulfate Sodium Salt. We subsequently investigated the gut microbiome composition using 16S rRNA sequencing. Result: After Ferment treatment, mouse body weight increased, and animals displayed less diarrhea, reduced frequency of bloody stools, and reduced inflammation in the colon. Beneficial bacteria belonging to Ileibacterium, Akkermansia, and Prevotellacea were enriched in the gut after Ferment treatment, while detrimental organisms including Erysipelatoclostridium, Dubosiella, and Alistipes were reduced. Conclusion: These data place Ferment as a promising dietary candidate for enhancing immunity and protecting against UC.

4.
Front Neurol ; 15: 1398225, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38962476

RESUMO

Background: It is vital to accurately and promptly distinguish unstable from stable intracranial aneurysms (IAs) to facilitate treatment optimization and avoid unnecessary treatment. The aim of this study is to develop a simple and effective predictive model for the clinical evaluation of the stability of IAs. Methods: In total, 1,053 patients with 1,239 IAs were randomly divided the dataset into training (70%) and internal validation (30%) datasets. One hundred and ninety seven patients with 229 IAs from another hospital were evaluated as an external validation dataset. The prediction models were developed using machine learning based on clinical information, manual parameters, and radiomic features. In addition, a simple model for predicting the stability of IAs was developed, and a nomogram was drawn for clinical use. Results: Fourteen machine learning models exhibited excellent classification performance. Logistic regression Model E (clinical information, manual parameters, and radiomic shape features) had the highest AUC of 0.963 (95% CI 0.943-0.980). Compared to manual parameters, radiomic features did not significantly improve the identification of unstable IAs. In the external validation dataset, the simplified model demonstrated excellent performance (AUC = 0.950) using only five manual parameters. Conclusion: Machine learning models have excellent potential in the classification of unstable IAs. The manual parameters from CTA images are sufficient for developing a simple and effective model for identifying unstable IAs.

5.
Food Chem ; 458: 140330, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38970953

RESUMO

Food safety is an important cornerstone of protecting human health and life. Therefore, it is of great significance to detect possible pollutants in food sensitively and efficiently. Molecularly imprinted polymers (MIPs) and metal-organic frameworks (MOFs) have been widely used in the adsorption and detection of food pollutants. However, traditional MIPs have problems such as uneven loading of the imprinted cavity and slow mass transfer efficiency. While the adsorption of MOFs has low specificity and cannot accurately identify target molecules. Therefore, some researchers have taken advantage of the high specific recognition abilities of MIPs and the large specific surface areas, high porosity and easy functionalization of MOFs to combine MOFs with MIPs, and have achieved a series of important results in the field of food safety detection. This paper reviews the research progress of the application of MOFs-MIPs in the field of food safety detection from 2019 to 2024. It furnishes researchers interested in this domain with a rapid and comprehensive grasp of the latest research status, it also offers them a chance to anticipate future development trends, thereby supporting the continuous advances of MOFs-MIPs in food safety detection.

6.
Biosens Bioelectron ; 256: 116260, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38613935

RESUMO

Various bioelectronic noses have been recently developed for mimicking human olfactory systems. However, achieving direct monitoring of gas-phase molecules remains a challenge for the development of bioelectronic noses due to the instability of receptor and the limitations of its surrounding microenvironment. Here, we report a MXene/hydrogel-based bioelectronic nose for the sensitive detection of liquid and gaseous hexanal, a signature odorant from spoiled food. In this study, a conducting MXene/hydrogel structure was formed on a sensor via physical adsorption. Then, canine olfactory receptor 5269-embedded nanodiscs (cfOR5269NDs) which could selectively recognize hexanal molecules were embedded in the three-dimensional (3D) MXene/hydrogel structures using glutaraldehyde as a linker. Our MXene/hydrogel-based bioelectronic nose exhibited a high selectivity and sensitivity for monitoring hexanal in both liquid and gas phases. The bioelectronic noses could sensitively detect liquid and gaseous hexanal down to 10-18 M and 6.9 ppm, and they had wide detection ranges of 10-18 - 10-6 M and 6.9-32.9 ppm, respectively. Moreover, our bioelectronic nose allowed us to monitor hexanal levels in fish and milk. In this respect, our MXene/hydrogel-based bioelectronic nose could be a practical strategy for versatile applications such as food spoilage assessments in both liquid and gaseous systems.


Assuntos
Técnicas Biossensoriais , Nariz Eletrônico , Técnicas Biossensoriais/métodos , Animais , Gases/química , Gases/análise , Aldeídos/química , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Cães , Receptores Odorantes/química , Humanos , Leite/microbiologia , Leite/química , Desenho de Equipamento , Odorantes/análise
7.
Quant Imaging Med Surg ; 14(4): 2993-3005, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38617165

RESUMO

Background: It is crucial to distinguish unstable from stable intracranial aneurysms (IAs) as early as possible to derive optimal clinical decision-making for further treatment or follow-up. The aim of this study was to investigate the value of a deep learning model (DLM) in identifying unstable IAs from computed tomography angiography (CTA) images and to compare its discriminatory ability with that of a conventional logistic regression model (LRM). Methods: From August 2011 to May 2021, a total of 1,049 patients with 681 unstable IAs and 556 stable IAs were retrospectively analyzed. IAs were randomly divided into training (64%), internal validation (16%), and test sets (20%). Convolutional neural network (CNN) analysis and conventional logistic regression (LR) were used to predict which IAs were unstable. The area under the curve (AUC), sensitivity, specificity and accuracy were calculated to evaluate the discriminating ability of the models. One hundred and ninety-seven patients with 229 IAs from Banan Hospital were used for external validation sets. Results: The conventional LRM showed 11 unstable risk factors, including clinical and IA characteristics. The LRM had an AUC of 0.963 [95% confidence interval (CI): 0.941-0.986], a sensitivity, specificity and accuracy on the external validation set of 0.922, 0.906, and 0.913, respectively, in predicting unstable IAs. In predicting unstable IAs, the DLM had an AUC of 0.771 (95% CI: 0.582-0.960), a sensitivity, specificity and accuracy on the external validation set of 0.694, 0.929, and 0.782, respectively. Conclusions: The CNN-based DLM applied to CTA images did not outperform the conventional LRM in predicting unstable IAs. The patient clinical and IA morphological parameters remain critical factors for ensuring IA stability. Further studies are needed to enhance the diagnostic accuracy.

8.
Nat Commun ; 15(1): 1347, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38355644

RESUMO

Accurate identification and localization of multiple abnormalities are crucial steps in the interpretation of chest X-rays (CXRs); however, the lack of a large CXR dataset with bounding boxes severely constrains accurate localization research based on deep learning. We created a large CXR dataset named CXR-AL14, containing 165,988 CXRs and 253,844 bounding boxes. On the basis of this dataset, a deep-learning-based framework was developed to identify and localize 14 common abnormalities and calculate the cardiothoracic ratio (CTR) simultaneously. The mean average precision values obtained by the model for 14 abnormalities reached 0.572-0.631 with an intersection-over-union threshold of 0.5, and the intraclass correlation coefficient of the CTR algorithm exceeded 0.95 on the held-out, multicentre and prospective test datasets. This framework shows an excellent performance, good generalization ability and strong clinical applicability, which is superior to senior radiologists and suitable for routine clinical settings.


Assuntos
Anormalidades Múltiplas , Aprendizado Profundo , Humanos , Estudos Prospectivos , Raios X , Cardiomegalia/diagnóstico por imagem
9.
Sci Total Environ ; 912: 168832, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38036131

RESUMO

The aptamer (Apt) and the molecularly imprinted polymer (MIP), as effective substitutes for antibodies, have received widespread attention from researchers because of their creation. However, the low stability of Apt in harsh detection environment and the poor specificity of MIP have hindered their development. Therefore, some researchers have attempted to combine MIP with Apt to explore whether the effect of "1 + 1 > 2" can be achieved. Since its first report in 2013, MIP-Apt dual recognition elements have become a highly focused research direction in the fields of biology and chemistry. MIP-Apt dual recognition elements not only possess the high specificity of Apt and the high stability of MIP in harsh detection environment, but also have high sensitivity and affinity. They have been successfully applied in medical diagnosis, food safety, and environmental monitoring fields. This article provides a systematic overview of three preparation methods for MIP-Apt dual recognition elements and their application in eight different types of sensors. It also provides effective insights into the problems and development directions faced by MIP-Apt dual recognition elements.


Assuntos
Impressão Molecular , Polímeros Molecularmente Impressos , Inocuidade dos Alimentos , Impressão Molecular/métodos
11.
ACS Sens ; 8(7): 2750-2760, 2023 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-37409469

RESUMO

Bioelectronic tongues based on umami taste receptors have recently been reported for versatile applications such as food analyses. However, their practical applications are still limited, partly due to their limited stability and non-specific responses in real sample environments. Herein, we have developed a hydrogel-based bioelectronic tongue for the sensitive assessment of umami intensity in fish extract samples. In this study, the T1R1 venus flytrap of an umami taste receptor was immobilized on the gold floating electrodes of a carbon nanotube-based field-effect transistor. A polyacrylamide conducting hydrogel film was further hybridized on the sensor surface via physical adsorption, which could provide a good physiological environment to maintain the activity of receptors due to its excellent hydrophilicity and biocompatibility. The bioelectronic tongue with a receptor-embedded hydrogel structure showed a sensitive detection of umami substances down to 1 fM, and it also had a wide detection range of 10-15-10-2 M for monosodium glutamate and disodium inosinate, which covers the human taste threshold. More importantly, the proposed sensor could significantly reduce the non-specific binding of non-target molecules to a carbon nanotube channel as well as exhibit long-term stability, enabling sensitive detection of umami substances even in fish extract samples. Our hydrogel-based bioelectronic tongue provides a promising platform for future applications such as the flavor evaluation of foods and beverages.


Assuntos
Nanotubos de Carbono , Papilas Gustativas , Animais , Humanos , Paladar/fisiologia , Hidrogéis , Língua/fisiologia
12.
J Agric Food Chem ; 71(20): 7847-7857, 2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37170887

RESUMO

In this work, broad-spectrum aptamers for organophosphorus pesticides (OPs) were obtained by alternate target systematic evolution of ligands by exponential enrichment screening. The secondary and tertiary structure analyses of the aptamer inferred that the neck-loop structure formed a G-triplex structure with the target. In addition, optimization of the sheared aptamer resulted in a stronger affinity (Kd = 86.74 nM), which was increased by 2 orders of magnitude compared to similar aptamers. A novel electrochemical biosensor was prepared by modifying an aptamer labeled with an electroactive substance (methylene blue) on the surface of nanoporous carbon containing Fe-Co (Fe-Co/NPC). When a target bound to the aptamer, a G-triplex structure was formed close to the electrode surface. The aptamer phosphate backbone labeled with methylene blue enhanced the electron-transfer efficiency and resulted in signal changes. The biosensor exhibited an excellent sensitivity (7.32 fM) and a wide detection range (1 × 10-13 to 1 × 10-3 M) for OPs under optimal conditions, enabling simultaneous detection of multiple OPs in vegetables.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanoporos , Praguicidas , Carbono , Compostos Organofosforados/análise , Aptâmeros de Nucleotídeos/química , Praguicidas/química , Azul de Metileno , Técnicas Biossensoriais/métodos , Limite de Detecção , Técnicas Eletroquímicas
13.
Acad Radiol ; 30(7): 1247-1256, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36400706

RESUMO

RATIONALE AND OBJECTIVES: To prospectively investigate the potential correlation between qualitative and quantitative assessment of aneurysm wall enhancement (AWE) on initial enhanced high-resolution magnetic resonance imaging (HR-MRI) and aneurysm progression during follow-up. MATERIALS AND METHODS: From June 2016 to January 2021, we prospectively recruited patients with unruptured intracranial aneurysms (UIAs) for enhanced HR-MRI examination. The patients' demographic and clinical data and aneurysm characteristics, including AWE features, were collected and analyzed. Follow-up images were compared to evaluate IA progression. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify the risk factors associated with aneurysm progression. RESULTS: Seventy-seven patients with 95 UIAs met our research criteria, and the median follow-up time was 15.7 months. Progression was observed in 18 aneurysms; the remaining 77 remained stable. Progressive UIAs were larger in size, more frequently displayed obvious AWE and showed a higher enhancement ratio (ER) than nonprogressive UIAs. Multivariate Cox regression analysis showed that both ER (hazard ratio, 6.304, p < 0.001) and aneurysm size (hazard ratio, 1.343, p = 0.014) were independent risk factors for aneurysm progression. The combination of ER and aneurysm size had an area under the curve of 0.920 for the prediction of aneurysm progression, with a sensitivity of 88.9% and specificity of 87.0%. CONCLUSION: A higher ER value of the aneurysm wall and a larger aneurysm size on initial HR-MRI may predict an increased risk of aneurysm progression, which suggests that closer monitoring by imaging or preventive intervention may be required for the clinical management of these aneurysms.


Assuntos
Aneurisma Intracraniano , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Seguimentos , Estudos Prospectivos , Imageamento por Ressonância Magnética/métodos , Fatores de Risco
14.
Int J Biol Macromol ; 224: 292-305, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36261073

RESUMO

The cell surface of lactic acid bacteria (LAB) plays an essential role in cell-cell and cell-host interactions. Exopolysaccharides (EPSs) are produced on the cell surface of LAB or in the surrounding medium and are considered to be in favor of the strain- specific probiotic surface characteristics. In this work, the structure features of EPS from Lacticaseibacillus paracasei S-NB were analyzed preliminarily, and the genes involved in EPS biosynthesis of S-NB strain were hypothesized and annotated, and their role in phenotypic characteristics were demonstrated by gene deletion analysis. Four mutant strains with deletion of crucial genes involved in EPS synthesis were analyzed for strain characteristics that are closely related to their ability to interact with the host intestinal epithelium cells, including strain surface characteristics and viability under the gastrointestinal stress conditions (both acid and bile stress). Furthermore, the adherence and immunomodulatory properties of wild-type S-NB and its mutant strains were compared using Caco-2 and RAW 264.7 cell lines, respectively. Taken together, the results indicated the importance of genes associated with EPS biosynthesis in L. paracasei S-NB as a determinant in strain surface characteristics and cell-host interaction, especially for S-NB_2176 (responsible for EPS polymerization) and S-NB_2175 (responsible for CpsD/CapB family tyrosine-protein kinase).


Assuntos
Lacticaseibacillus paracasei , Probióticos , Humanos , Lacticaseibacillus , Células CACO-2 , Mucosa Intestinal/metabolismo , Polissacarídeos Bacterianos/química
15.
Biosens Bioelectron ; 220: 114785, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36323163

RESUMO

In this work, a portable electrochemiluminescence (ECL) detection system based on silicon photomultiplier (SiPM) single photon detector was proposed for the detection of ECL signals on a screen-printed electrode (SPE). This instrument innovatively used SiPM single photon detector to detect the ECL signal, which solved friability and bloat caused by the high operating voltage and the limitation of detection components in the traditional ECL detection instrument. This detection instrument showed excellent electrochemical and ECL detection performance. On this basis, an aptasensor based on silver (core)-gold (shell) bimetallic nanoparticles (Ag@AuNPs) was constructed for the detection of tetracycline (TET) in milk on SPE. Here, Ag@AuNPs had a significant effect in enhancing luminol ECL signal and immobilizing aptamer. The concentration of TET was detected according to the changes of the ECL signal intensity of the detection instrument. This instrument exhibited an excellent linearity ranging from 0.01 ng/mL to 1,000 ng/mL for the detection of TET, and a limit of detection (LOD) was 0.0053 ng/mL. The developed portable ECL detection instrument provides a new platform for the detection of small molecule contaminants.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanopartículas Metálicas , Animais , Ouro/química , Aptâmeros de Nucleotídeos/química , Nanopartículas Metálicas/química , Leite/química , Técnicas Eletroquímicas , Medições Luminescentes , Limite de Detecção , Tetraciclina/análise , Antibacterianos/análise
16.
Imeta ; 2(2): e90, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-38868421

RESUMO

In this longitudinal cohort study, our results demonstrated that there are rhythmic changes in gut microbial network signatures in early life, and healthy infants adopt more complex and stable network structure in their gut microbiota than that of the infants with eczema.

17.
Front Med (Lausanne) ; 9: 930678, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36250101

RESUMO

Background: Talaromyces marneffei (T. marneffei) is an opportunistic fungal pathogen commonly found in human immunodeficiency virus (HIV) patients that often infects lymph nodes. Knowledge about the computed tomography (CT) characteristics of T. marneffei lymphadenopathy in HIV patients is limited. The aim of this study was to investigate the clinical and CT characteristics of T. marneffei lymphadenopathy to improve its diagnosis and promote recognition of this type of infection in radiology. Methods: Between February 2019 and June 2021, we retrospectively reviewed the clinical features and CT characteristics of T. marneffei lymphadenopathy in 21 HIV patients. Results: The clinical symptoms of T. marneffei infection are non-specific. Anemia (100%), fever (85.7%) and cough and sputum production (76.2%) were the most frequent symptoms. Multiple lymphadenopathies, mainly in the mediastinum (76.2%) and mesentery (82.4%), can be fused (14.3%) and necrotic (52.4%), with slight (41.7%) and moderate enhancement (58.3%) that is heterogeneous. In addition to involving the lymph nodes, the lesions involved the lungs (81.0%), liver and spleen (42.9%), and small intestine (14.3%). Conclusions: T. marneffei is prone to affecting lymph nodes and extranodal organs in HIV patients. Although the clinical manifestations of T. marneffei infection are not specific, the possibility of T. marneffei infection should be considered if CT findings indicate multiple lesion sites.

18.
Carbohydr Polym ; 296: 119971, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36088010

RESUMO

Exopolysaccharide (EPS) isolated from Lactobacillus helveticus SNA12 were purified, and one fraction (SNA12-EPS) was obtained. The structure of SNA12-EPS was proposed using Fourier-transform infrared spectroscopy, gas chromatography-mass spectrometry, and nuclear magnetic resonance. Results showed that SNA12-EPS was rich in galactose and glucose with the molar ratios of 2.1:1.0, and SNA12-EPS possessed the repeat units of →3)-ß-D-Glcp-(1→3)-ß-D-Glcp-(1→4)-ß-D-Galp-(1→ with an average molecular weight of 3.81 × 105 Da. The scanning electron microscope results showed that SNA12-EPS had a tight structure with a smooth and uneven surface. Furthermore, the prebiotic potential of SNA12-EPS was performed using in vitro simulated digestion with human faecal fermentation. SNA12-EPS was not digested by digestive juice, and it could markedly regulate the gut microbiota composition by increasing the relative abundances of Parabacteroides and Blautia and decreasing the abundance of pathogenic bacteria of Fusobacterium. Additionally, SNA12-EPS improved the ability of gut microbiota to produce short-chain fatty acids.


Assuntos
Lactobacillus helveticus , Carboidratos da Dieta , Fermentação , Humanos , Peso Molecular , Polissacarídeos Bacterianos/química
19.
Food Chem ; 397: 133838, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-35944333

RESUMO

The bioelectronic tongues based on taste receptors have been emerging with human-like taste perception. However, the practical applications of the receptor-based biosensors were restricted by their narrow and low dynamic ranges. Here, a novel immobilization strategy based on AuNPs@ZIF-8/Ti3C2 MXene was developed to immobilize the umami ligand binding domain (T1R1-VFT), to fabricate an umami biosensor for umami substances detection. Through the synergic effect of AuNPs@ZIF-8 and Ti3C2 MXene, the capacity to load T1R1-VFT was effectively increased, and the response signal was also amplified by approximately 3 times. The proposed biosensor showed an ultrawide dynamic range of 10-11-10-3 M, and a high upper limit of detection, which was closer to the human taste threshold and suitable for detecting foods rich in umami substances. Additionally, the biosensor was successfully applied to detect real samples and analyze the synergistic effects of binary umami substances.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Ouro , Humanos , Receptores Acoplados a Proteínas G/metabolismo , Paladar , Titânio/química
20.
J Hazard Mater ; 440: 129707, 2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-35986944

RESUMO

For the visual detection of four organophosphorus pesticides (OPs), a colorimetric aptasensor was developed based on aptamer-mediated bimetallic metal-organic frameworks (MOFs) nano-polymers. Fe-Co magnetic nanoparticles (MNPs) and Fe-N-C nanozymes were prepared based on pyrolytic reaction, and were labeled with broad spectrum aptamers and complementary chains of organophosphorus pesticides respectively. The hybridization of aptamers and complementary chains led to the formation of nano-polymers. In the presence of target pesticides, they competed with complementary chains for aptamers on Fe-Co MNPs, resulting in a large number of Fe-N-C nanozymes signal labels being released into the supernatant. Fe-N-C nanozymes showed similar activity to peroxidase and catalyzed the 3,3',5,5'-tetramethylbenzidine-hydrogen peroxide (TMB-H2O2) color system to turn the solution blue-green under mild conditions. The magnetic probes had good selectivity and sensitivity, and were easily separated by magnetic absorption. The sensor functioned well under optimal conditions, demonstrating good stability and specificity for four pesticides: phorate, profenofos, isocarbophos and omethoate, and the detection limits of four pesticides were as low as 0.16 ng/mL, 0.16 ng/mL, 0.03 ng/mL and 1.6 ng/mL respectively, and the recovery rate of OPs residue in vegetable samples was satisfactory. The work described here provided a simple, rapid and sensitive way to construct a biosensor.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Estruturas Metalorgânicas , Praguicidas , Aptâmeros de Nucleotídeos/química , Colorimetria/métodos , Peróxido de Hidrogênio , Limite de Detecção , Estruturas Metalorgânicas/química , Compostos Organofosforados , Peroxidases , Praguicidas/análise , Forato
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