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1.
Talanta ; 281: 126900, 2025 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-39305760

RESUMEN

Rapid and selective separation, enrichment and detection of trace residue all-in-one in complex samples is a major challenge. Hydrogels with molecular sieve properties can selectively separate and enrich target analytes, and the combination with high sensitivity detection of surface-enhanced Raman scattering (SERS) is expected to achieve the above all-in-one detection. Herein, the core-shell structured Au@poly(N-isopropylacrylamide)-phenylboronic acid hydrogel (Au@PNIP-VBA) with boronic acid ester groups was prepared by thermally initiated polymerization. The boronic acid ester groups in hydrogel are selectively hydrolyzed by hydrogen peroxide (H2O2) to hydroxyl structures, leading to a reduction in SERS signals. The Au@PNIP-VBA hydrogel has molecular sieve properties and high SERS activity, making it suitable for separation, enrichment, hydrolysis and detection of H2O2 all-in-one. A rapid SERS method was developed for analysis of H2O2 based on the Au@PNIP-VBA hydrogel with the linear range of 8.5 × 10-2-6.8 mg L-1 and the detection limit of 33 µg L-1. The method was successfully applied to the determination of H2O2 residue in fresh milk, pure milk, yogurt and camel milk, with the recoveries were in the range of 82.2%-109.3% and the relative standard deviations were 2.8%-8.3%. This efficient all-in-one strategy has the advantages of simple sample pre-treatment, rapid analysis (30 min) and high sensitivity, making it highly promising for food quality and safety analysis.


Asunto(s)
Ácidos Borónicos , Ésteres , Hidrogeles , Peróxido de Hidrógeno , Espectrometría Raman , Peróxido de Hidrógeno/química , Ácidos Borónicos/química , Espectrometría Raman/métodos , Hidrogeles/química , Hidrólisis , Animales , Ésteres/química , Ésteres/análisis , Oro/química , Productos Lácteos/análisis , Resinas Acrílicas/química , Propiedades de Superficie , Leche/química , Límite de Detección , Contaminación de Alimentos/análisis
2.
Mikrochim Acta ; 191(11): 640, 2024 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-39356328

RESUMEN

Chiral compounds are abundantly distributed in both the natural world and biological systems. It is crucial to identify and detect chiral compounds in living systems or to separate and determine them in the natural environment. Many researchers have developed a range of chiral materials with different functionalizations to separate and detect chiral substances. Chiral metal-organic frameworks (CMOFs) have the potential to be used in enantioselective separation and detection due to their large surface areas, regulated framework topologies, particular substrate interactions, and accessible chiral sites. CMOFs contribute significantly to the development of enantiomer separation and detection in medicine, agriculture, food, environment, and other fields. This review focuses on four synthesis methods of CMOFs and their applications in chiral separation and chiral sensing in the past five years, mainly including chromatographic separation, membrane separation, optical sensing, electrochemical sensing, and other sensing methods. Finally, the challenges and potential growth direction of CMOFs in enantiomer separation and detection are discussed and prospected.

3.
Anal Chem ; 2024 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-39453892

RESUMEN

The use of nanozymes has become a promising auxiliary approach to "turn on" surface-enhanced Raman scattering (SERS) signals for the label-free detection of disease markers. Nevertheless, there are still major challenges to develop bifunctional nanomaterials with both excellent enzyme-like activity and high SERS performance. To this end, a novel Z-scheme MoO3-x/CuS heterojunction was first constructed as a powerful "two-in-one" substrate, which can not only catalyze leucomalachite green (LMG) to SERS-active malachite green (MG) but also serve as an efficient substrate to amplify the SERS signal of catalysate. Due to the strong interfacial coupling effect between the MoO3-x and CuS nanomaterial, which promoted the separation and transport of carriers in the heterojunction, the MoO3-x/CuS heterojunction showed higher peroxidase-like activity compared to individual components and the previously reported heterojunction nanozymes. Inspired by these results, a sandwich-type SERS immunoassay for the detection of the cerebral infarction biomarker S100 calcium-binding protein (S100B) was proposed based on the output signal of MG at 1620 cm-1. Furthermore, introducing the antifouling material chitosan on the surface of the MoO3-x/CuS heterojunction can effectively resist nonspecific protein adsorption and significantly improve the detection accuracy of the immunoassay. Therefore, the SERS immunoassay based on the MoO3-x/CuS heterojunction realized highly sensitive and selective detection of S100B in the concentration range of 0.001 to 100 ng/mL, with a low limit of detection of 0.47 pg/mL. The developed method has been successfully used for the accurate detection of S100B in clinical serum. The results showed that the level of S100B in the serum of cerebral infarction patients can be distinguished from those of healthy individuals and intracranial tumor patient controls. In addition, the acquired values of S100B in the serum of cerebral infarction patients based this strategy were well consistent with the results of electrochemiluminescence (ECL) detection with a relative error of less than ±7.3. It is expected that this work may open up a paradigm for improving detection sensitivity and accuracy for the early diagnosis and treatment monitoring of cerebral infarction in the clinic.

4.
J Chromatogr A ; 1736: 465398, 2024 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-39342731

RESUMEN

Sample preparation is crucial in analytical chemistry, impacting result accuracy, sensitivity, and reliability. Solid-phase separation media, especially adsorbents, are vital for preparing of liquid and gas samples, commonly analyzed by most analytical instruments. With the advancements in materials science, covalent organic frameworks (COFs) constructed through strong covalent bonds, have been increasingly employed in sample preparation in recent years. COFs have outstanding selectivity and/or excellent adsorption capacity for a single target or can selectively adsorb multiple targets from complex matrix, due to their large specific surface area, adjustable pore size, easy modification, and stable chemical properties. In this review, we summarize the classification of COFs, such as pristine COFs, COF composite particles, and COFs-based substrates. We aim to provide a comprehensive understanding of the different classifications of COFs in sample preparation within the last three years. The challenges and development trends of COFs in sample preparation are also presented.


Asunto(s)
Estructuras Metalorgánicas , Estructuras Metalorgánicas/química , Adsorción , Extracción en Fase Sólida/métodos , Porosidad
5.
J Chromatogr A ; 1734: 465298, 2024 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-39216285

RESUMEN

Acurate and sensitive determination of hazards from food contact materials is important to monitor food safety. It is necessary to excavate efficient adsorbent for simultaneous recognition and adsorption of food hazards of trace level for sample preparation. In this work, ß-cyclodextrin and calix[4]arene were employed as hybrid functional monomers to prepare macrocyclic porous organic polymer (ß-CD-CX4 POP). It was proved that the supramolecular cavities of ß-CD-CX4 POP could form inclusion complexes with fluorescent whitening agents (FWAs) through host-guest recognition, which greatly improved the adsorption performance. The hydrophobic cavities of ß-cyclodextrin and calix[4]arene of ß-CD-CX4 POP exhibited synergistic effect for simultaneous recognition of FWAs. The high-throughput enrichment of FWAs was realized by ß-CD-CX4 POP membranes coupled with a multiple-channel syringe pump. Based on membrane-based solid-phase extraction combined with UHPLC-MS/MS, a sensitive analytical method was established to determine six FWAs. The LODs was in range of 3-50 ng/L with the linear range of 0.02-100 µg/L. The developed method was used to quantify FWAs in bread wrapper and bread, and the spiked recoveries ranged from 78.1%-119% with RSD of 2.3%-9.7%. This work indicated that ß-CD-CX4 POP was promising for the simultaneous recognition and adsorption of FWAs migrating from food contact materials.


Asunto(s)
Calixarenos , Embalaje de Alimentos , Límite de Detección , Fenoles , Extracción en Fase Sólida , beta-Ciclodextrinas , beta-Ciclodextrinas/química , Calixarenos/química , Fenoles/análisis , Fenoles/aislamiento & purificación , Fenoles/química , Extracción en Fase Sólida/métodos , Cromatografía Líquida de Alta Presión/métodos , Porosidad , Adsorción , Espectrometría de Masas en Tándem/métodos , Contaminación de Alimentos/análisis , Polímeros/química , Colorantes Fluorescentes/química , Membranas Artificiales
6.
J Chromatogr A ; 1734: 465293, 2024 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-39181092

RESUMEN

The analysis of biological samples is highly valuable for disease diagnosis and treatment, forensic examination, and public safety. However, the serious matrix interference effect generated by biological samples severely affects the analysis of trace analytes. Sample preparation methods are introduced to address the limitation by extracting, separating, enriching, purifying trace target analytes from biological samples. With the raising demand of biological sample analysis, a review focuses on media for biological sample preparation and analysis over the last 5 years is presented. High-performance media in biological sample preparation are first reviewed, including porous organic frameworks, imprinted polymers, hydrogels, ionic liquids, and bioactive media. Then, application of media for different biological sample preparation and analysis is briefly introduced, including liquid samples of body fluids, solid samples (hair, feces, and tissues), and gas samples of exhale breath gas. Finally, conclusions and outlooks on media promoting biological sample preparation are presented.


Asunto(s)
Manejo de Especímenes , Humanos , Manejo de Especímenes/métodos , Líquidos Iónicos/química , Líquidos Corporales/química , Hidrogeles/química , Polímeros/química , Animales
7.
Anal Bioanal Chem ; 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39215774

RESUMEN

Biomarkers and their concentration levels are critical indicators of metabolomics for clinical applications. Rapid and sensitive analysis methods are essential for realizing timely and efficient quantitation of those significant biomarkers. In this work, a self-driven microfluidic immunosensor was developed for rapid all-in-one separation, enrichment, and detection of biomarkers. This immunosensor was constructed from a cyclic olefin copolymer (COC) channel layer and a polydimethylsiloxane (PDMS) sensing layer. The COC channel layer was modified through protein adsorption, immobilization, and remaining active site blocking. The obtained hydrophilic microchannels not only reduce the nonspecific adsorption, but also provide stable capillary-driven flow generation with linear velocities up to 20 mm/s for aqueous solution auto-injection. The PDMS sensing layer was modified using capture antibodies to accomplish affinity recognition of target biomarkers. Procalcitonin (PCT) and serum amyloid A (SAA) were selected as model biomarkers in the feasibility study on applying the self-driven microfluidic immunosensor to bioassay. The limits of detection of PCT and SAA were 7.9 ng/L and 7.6 µg/L, respectively. Moreover, the whole process can be accomplished within 60 min with excellent selectivity and reproducibility. In clinical serum sample analysis, satisfactory recoveries were achieved for PCT and SAA in the ranges of 85.0-103.0% and 95.5-106.0%, respectively, with relative standard deviations less than 5.3%. The method accuracy was further confirmed by the results of commercial immunoassay kits. This simple and easily operated immunosensor provides a rapid and sensitive biomarker analysis tool, and promotes the further development of automated and easy-to-use microfluidic immunoassays.

8.
J Sep Sci ; 47(15): e2400415, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39118576

RESUMEN

Porous cage materials with certain dimensions, sizes, shapes, and functions have been regarded as promising materials for sample preparation, chromatographic separation, and detection process. In contrast to infinite frameworks such as metal-organic frameworks or covalent organic frameworks, porous cage materials are constructed from discrete molecules containing at least one internal cavity. The well-defined cavities in porous cage materials provide opportunities for non-covalent interactions. These interactions can be programmed into the ligand design or supramolecular cage constructing using the cages as building blocks, offering various host-guest recognition with great selectivity. In this review, we desire to elucidate the fundamental principles governing the design and fabrication of porous cage materials with well-defined cavities, good solvent processability, and modifiable groups, the applications of these porous cage materials in sample preparation, chromatographic separation, and detection were discussed. The recent advantages of porous cage materials for the analysis process were summarized. We state the potential of these materials and provide an outlook for further application strategies. We expect that this review can inspire interest in the porous cage materials research area for analysis.

9.
Anal Chem ; 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39007488

RESUMEN

Monitoring changes in the expression of marker proteins in biological fluids is essential for biomarker-based disease diagnosis. Epithelial cell adhesion molecule (EpCAM) has been identified as a broad-spectrum biomarker for various chronic diseases and as a therapeutic target. However, the development of simple and reliable methods for quantifying EpCAM changes in biological fluids faces challenges due to the variability of its expression across different diseases, the presence of soluble forms, and matrix effects. In this paper, a surface-enhanced Raman scattering (SERS)-fluorescence (FL) dual-mode sensing method was established for quantification of trace EpCAM in biological fluids based on bimetallic Au@Ag nanoparticles and nitrogen-doped quantum dots encapsulated DNA hydrogel hybrid with graphene oxide (Au@Ag-NQDs/GO). The DNA hydrogel was constructed based on three-dimensional (3D) structure DNA-mediated strategy using an aptamer DNA (AptDNA) linker. The interaction of the AptDNA with EpCAM triggered the disassembly of the DNA hydrogel. Consequently, the release of Au@Ag nanoparticles induced an "on-off" switch in the SERS signal while the weakened FL quenching effect in Au@Ag-NQDs/GO system achieved "off-on" switch of FL signal, enabling the simultaneous SERS-FL quantification of EpCAM. The established dual-mode method exhibited outstanding sensitivity and stability in quantifying EpCAM in the range of 0.5-60.0 pg/mL, with the limits of detection (LODs) of SERS and FL as 0.17 and 0.35 pg/mL, respectively. When applied for real sample analysis, the method showed satisfactory specificity and recoveries in cancer cells lysate, serum, and urine samples with RSDs of 2.8-6.3%, 4.0-6.3%, and 2.8-5.7%, respectively. The developed SERS-FL sensing method offered a sensitive, reliable, and practical quantification strategy for trace EpCAM in diverse biological fluid samples, which would benefit the early diagnosis of disease and further health management.

10.
Anal Chem ; 96(27): 11036-11043, 2024 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-38934556

RESUMEN

Escherichia coli O157:H7 is one of the most susceptible foodborne pathogens, easily causing food poisoning and other health risks. It is of great significance to establish a quantitative method with higher sensitivity and less time consumption for foodborne pathogens analysis. The Raman-silent signal has a good performance for avoiding interference from the food matrix so as to achieve accurate signal differentiation. In this work, we presented a preparation-mapping all-in-one method for digital mapping analysis. We prepared a functionalized Raman-silent polymer label of Escherichia coli O157:H7, which was captured on a porous 4-mercaptophenylboric acid@Ag foam chip. To improve accuracy and widen the detection range, a digital mapping quantitative strategy was employed in data extraction and processing. By transfer mapping information into digitized statistical results, the limitation of obtaining reproducible intensity values just by randomly selected spots on the substrate can be addressed. With a wide linear range of 1.0 × 101-1.0 × 105 CFU mL-1 and a limit of detection of 4.4 CFU mL-1, this all-in-one method had good sensitivity performance. Also, this method achieved good precision and selectivity in a series of experiments and was successfully applied to the analysis of beverage samples.


Asunto(s)
Bebidas , Escherichia coli O157 , Polímeros , Espectrometría Raman , Escherichia coli O157/aislamiento & purificación , Espectrometría Raman/métodos , Bebidas/análisis , Bebidas/microbiología , Polímeros/química , Compuestos de Boro/química , Microbiología de Alimentos/métodos , Contaminación de Alimentos/análisis , Compuestos de Sulfhidrilo/química , Compuestos de Sulfhidrilo/análisis , Ácidos Borónicos
11.
J Chromatogr A ; 1728: 465014, 2024 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-38797135

RESUMEN

Developing novel chiral stationary phases (CSPs) with versatility is of great importance in enantiomer separation. This study fabricated a dual-chiral covalent organic framework (PA-CA COF) via successive post-synthetic modifications. The chiral trans-1,2-cyclohexanediamine (CA) and (D)-penicillamine (PA) groups were periodically aligned within nanochannels of the COF, allowing selective recognition of enantiomers through intermolecular interactions. It can be a versatile high-performance liquid chromatography (HPLC) CSP for separating a wide range of enantiomers, including chiral pharmaceutical intermediates and chiral drugs. With separation performance comparable to commercial chiral columns and even greater versatility, the PA-CA COF@SiO2 column held promise for practical applications. Chiral separation results combined with molecular simulation indicated that the mixed mode of PA and CA resulted in the broad separation capability of PA-CA COF. The introduction of the dual-chiral COFs concept opens up a new avenue for chiral recognition and separation, holding great potential for practical enantiomer separation.


Asunto(s)
Penicilamina , Estereoisomerismo , Cromatografía Líquida de Alta Presión/métodos , Penicilamina/química , Penicilamina/aislamiento & purificación , Ciclohexilaminas/química , Ciclohexilaminas/aislamiento & purificación , Dióxido de Silicio/química , Estructuras Metalorgánicas/química
12.
J Chromatogr A ; 1721: 464849, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38564930

RESUMEN

A novel fluorinated covalent organic polymer @ attapulgite composite (F-COP@ATP) was prepared at room temperature for in-syringe membrane solid-phase extraction (SM-SPE) of domoic acid (DA) in aquatic products. Natural ore ATP has the advantages of low cost, good mechanical strength and abundant hydroxyl group on its surface, and in-situ modified F-COP layer can provide abundant adsorption sites. F-COP@ATP combining the advantages of F-COP and ATP, becomes an ideal adsorbent for DA extracting. Moreover, a high-throughput sample preparation strategy was carried out by using the F-COP@ATP membrane as syringe filter and assembling syringes with a ten-channel injection pump. In addition, the experimental factors were optimized, such as pH of extract, amount of adsorbent, velocity of extraction and desorption, type and volume of desorption solvent. The DA analytical method was established by SM-SPE-HPLC/tandem mass spectrometry. The method had a wide linear range with low limit of detection (0.344 ng/kg) and low limit of quantification (1.14 ng/kg). F-COP@ATP membrane can be reused more than five times. The method realized the analysis of DA in scallop and razor clam samples, which shows its application prospect in practical analysis. This study provided an efficient, low-energy and mild idea for preparing other reusable natural mineral ATP-based composite materials for separation and enrichment, which reduces the experimental cost and is closer to environmental protection and green chemistry to a certain extent.


Asunto(s)
Polímeros de Fluorocarbono , Ácido Kaínico/análogos & derivados , Compuestos de Magnesio , Compuestos de Silicona , Extracción en Fase Sólida , Temperatura , Cromatografía Líquida de Alta Presión/métodos , Extracción en Fase Sólida/métodos , Adenosina Trifosfato
13.
Biosensors (Basel) ; 14(4)2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38667156

RESUMEN

Covalent organic frameworks (COFs) are porous crystals that have high designability and great potential in designing, encapsulating, and immobilizing nanozymes. COF nanozymes have also attracted extensive attention in analyte sensing and detection because of their abundant active sites, high enzyme-carrying capacity, and significantly improved stability. In this paper, we classify COF nanozymes into three types and review their characteristics and advantages. Then, the synthesis methods of these COF nanozymes are introduced, and their performances are compared in a list. Finally, the applications of COF nanozymes in environmental analysis, food analysis, medicine analysis, disease diagnosis, and treatment are reviewed. Furthermore, we also discuss the application prospects of COF nanozymes and the challenges they face.


Asunto(s)
Estructuras Metalorgánicas , Estructuras Metalorgánicas/química , Técnicas Biosensibles , Nanoestructuras , Química Analítica , Análisis de los Alimentos , Técnicas de Química Analítica/métodos
14.
Sensors (Basel) ; 24(7)2024 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-38610279

RESUMEN

This review introduces a micro-integrated device of microfluidics and fiber-optic sensors for on-site detection, which can detect certain or several specific components or their amounts in different samples within a relatively short time. Fiber-optics with micron core diameters can be easily coated and functionalized, thus allowing sensors to be integrated with microfluidics to separate, enrich, and measure samples in a micro-device. Compared to traditional laboratory equipment, this integrated device exhibits natural advantages in size, speed, cost, portability, and operability, making it more suitable for on-site detection. In this review, the various optical detection methods used in this integrated device are introduced, including Raman, ultraviolet-visible, fluorescence, and surface plasmon resonance detections. It also provides a detailed overview of the on-site detection applications of this integrated device for biological analysis, food safety, and environmental monitoring. Lastly, this review addresses the prospects for the future development of microfluidics integrated with fiber-optic sensors.

15.
J Chromatogr A ; 1720: 464775, 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38452559

RESUMEN

The contents of target substances in biological samples are usually at low concentration levels, and the matrix of biological samples is usually complex. Sample preparation is considered a very critical step in bioanalysis. At present, the utilization of microextraction sampling technology has gained considerable prevalence in the realm of biological analysis. The key developments in this field focus on the efficient microextraction media and the miniaturization and automation of adaptable sample preparation methods currently. In this review, the recent progress on the microextraction sampling technologies for bioanalysis has been introduced from point of view of the preparation of microextraction media and the microextraction sampling strategies. The advance on the microextraction media was reviewed in detail, mainly including the aptamer-functionalized materials, molecularly imprinted polymers, carbon-based materials, metal-organic frameworks, covalent organic frameworks, etc. The advance on the microextraction sampling technologies was summarized mainly based on in-vivo sampling, in-vitro sampling and microdialysis technologies. Moreover, the current challenges and perspective on the future trends of microextraction sampling technologies for bioanalysis were briefly discussed.


Asunto(s)
Microextracción en Fase Sólida , Manejo de Especímenes , Microextracción en Fase Sólida/métodos , Tecnología , Polímeros Impresos Molecularmente , Automatización
16.
Talanta ; 273: 125901, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38503122

RESUMEN

Aromatic disinfection by-products (DBPs) have garnered considerable interest in recent years for their potential carcinogenicity. However, efficient separation and enrichment of DBPs in complex samples is a challenge due to the extremely low content of aromatic DBPs and the complexity of sample matrices. In this study, a MIL-101(Cr)-NH2@TAPB-DVA-COF hybrid material was prepared as the enrichment medium of membrane solid-phase extraction (M-SPE) to efficiently determine trace emerging aromatic DBPs. This medium exhibited excellent enrichment capacity and selectivity for aromatic DBPs because of the strong hydrogen bonding, π-π stacking and hydrophobic interactions. An efficient analytical method for five aromatic DBPs in juice drinks was successfully established by use of this hybrid material as the enrichment medium for M-SPE in combination with liquid chromatography tandem mass spectrometry (LC-MS/MS). The limits of detection of the established method were from 0.50 to 3.00 ng/L. Moreover, the method had been successfully used in real juice drinks to determine trace five aromatic DBPs with the spiked recoveries ranging from 84.1% to 125%. The method possessed high analytical sensitivity and accuracy for these five aromatic DBPs in juice drinks with the aid of the efficient M-SPE technology proposed.


Asunto(s)
Benzamidinas , Desinfección , Estructuras Metalorgánicas , Espectrometría de Masas en Tándem , Cromatografía Liquida , Desinfección/métodos , Espectrometría de Masas en Tándem/métodos , Extracción en Fase Sólida/métodos , Cromatografía Líquida de Alta Presión/métodos
17.
Anal Chem ; 96(14): 5368-5374, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38528372

RESUMEN

A gas membrane separation/array fluorescence visualization (GMS/AFV) device is developed by integrating hydrazine-based carbonized copolymer dots (PD-N2H4) for visual on-site analysis. The novel PD-N2H4 was synthesized using a "polymer template" approach, exhibiting strong blue fluorescence capable of visual sensing. The GMS/AFV device integrates sample preparation and detection all-in-one, consisting of a smartphone, a sample pretreatment system, and an optical system. In the detection procedure, the samples will be treated in the sample pretreatment system to create volatile gases. Therefore, any gas samples as well as solid and liquid samples that potentially produce volatile gases can be visually detected on-site by the device. H2S was utilized as a model analyte to test the practicality of the GMS/AFV device. The entire analysis can be finished in 3 min, and the limit of detection of H2S is as low as 3.4 µg/L. Surprisingly, the device is also capable of high-throughput sample detection, which can process 48 samples simultaneously in about 20 min. The device offers a quick, easy, cheap, and environmentally friendly way to analyze volatile gases, and it creates new opportunities for on-site detection of complex samples.

18.
Biosens Bioelectron ; 255: 116227, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38552524

RESUMEN

Food safety represents a critical global public health issue, with safety challenges posed by foodborne pathogens garnering extensive attention. Therefore, we introduce a co-recognition, enrichment and sensing (CES) all-in-one strategy for analysis of bacteria with low background and high specificity. This method employs antimicrobial peptide (AMP) functionalized magnetic nanoparticles (MNPs) to enrich bacteria and uses aptamer@Au@PBA (KxMFe(CN)6 (M = Pb and Ni)) NPs as silent SERS tags. When both S. aureus and E. coli O157:H7 are present, the silent SERS probes could specifically label the target bacteria, forming a sandwich-like structure. This binding induces silent Raman shifts (2139 cm-1 and 2197 cm-1), enabling quantification of two bacteria. Coupling with the modular flexible microfluidics and magnetic control slider device, this platform facilitates rapid switching between magnetic loading and elution. The CES SERS method demonstrated linear relationships for both S. aureus and E. coli O157:H7 at 50-1600 cfu mL-1, with detection limits of 14 and 18 cfu mL-1, respectively. The method achieved recovery rates of 85.6-112% and relative standard deviations of 1.5-8.6%. Validation using the ELISA method revealed relative errors between -7.5 and 4.3%. The CES approach has potential applications in food safety, environmental monitoring, and biomedical diagnosis.


Asunto(s)
Técnicas Biosensibles , Nanopartículas del Metal , Nanopartículas del Metal/química , Staphylococcus aureus , Escherichia coli , Microfluídica , Técnicas Biosensibles/métodos , Bacterias , Fenómenos Magnéticos , Espectrometría Raman/métodos , Oro/química
19.
Anal Chem ; 96(9): 3933-3941, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38359085

RESUMEN

Accurate discrimination of metal species is a significant analytical challenge. Herein, we propose a novel methodology based on liquid-phase cyclic chemiluminescence (CCL) for the identification of cobalt speciation. The CCL multistage signals (In) of the luminol-H2O2 reaction catalyzed by different cobalt species have different decay coefficients k. Thereby, we can facilely identify various cobalt species according to the distinguishable k values, including the complicated and structurally similar cobalt complexes, such as analogues of [Co(NH3)5X]n+ (X = Cl-, H2O, and NH3), Co(II) porphyrins, and bis(2,4-pentanedione) cobalt(II) derivatives. Especially, the number of substituent atoms also influences the k value greatly, which allows excellent discrimination between complexes that only have a subtle difference in the substituent group. In addition, linear discriminant analysis based on In provides a complementary solution to improve the differentiating ability. We performed density functional theory calculations to investigate the interaction mode of H2O2 over cobalt species. A close negative correlation between the adsorption energy and the k value is observed. Moreover, the calculation of energy evolutions of H2O2 decomposition into a double hydroxide radical shows that a high level of consistency exists between the activation energy barrier and the k value. The results further demonstrate that the decay coefficient of the CCL multistage signal is associated with the catalytic reactivity of the cobalt species. Our work not only broadens the application of chemiluminescence but also provides a complementary technology for speciation analysis.

20.
Anal Chem ; 2024 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-38335969

RESUMEN

The combined application of nanozymes and surface-enhanced Raman scattering (SERS) provides a promising approach to obtain label-free detection. However, developing nanomaterials with both highly efficient enzyme-like activity and excellent SERS sensitivity remains a huge challenge. Herein, we proposed one-step synthesis of Mo2N nanoparticles (NPs) as a "two-in-one" substrate, which exhibits both excellent peroxidase (POD)-like activity and high SERS activity. Its mimetic POD activity can catalyze the 3,3',5,5'-tetramethylbenzidine (TMB) molecule to SERS-active oxidized TMB (ox-TMB) with high efficiency. Furthermore, combining experimental profiling with theory, the mechanism of POD-like activity and SERS enhancement of Mo2N NPs was explored in depth. Benefiting from the outstanding properties of Mo2N NPs, a versatile platform for indirect SERS detection of biomarkers was developed based on the Mo2N NPs-catalyzed product ox-TMB, which acts as the SERS signal readout. The feasibility of this platform was validated using glutathione (GSH) and target antigens alpha-fetoprotein antigen (AFP) and carcinoembryonic antigen (CEA) as representatives of small molecules with a hydroxyl radical (·OH) scavenging effect and proteins with a low Raman scattering cross-section, respectively. The limits of detection of GSH, AFP, and CEA were as low as 0.1 µmol/L, 89.1, and 74.6 pg/mL, respectively. Significantly, it also showed application in human serum samples with recoveries ranging from 96.0 to 101%. The acquired values based on this platform were compared with the standard electrochemiluminescence method, and the relative error was less than ±7.3. This work not only provides a strategy for developing highly active bifunctional nanomaterials but also manifests their widespread application for multiple biomarkers analysis.

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