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1.
Anal Chem ; 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39405304

RESUMO

Chiral film-based sensors show great promise for discriminating between enantiomers due to their miniaturization and low power consumption. However, their practical use is hindered by the trade-off between enantioselectivity and mass transfer capability, especially concerning biomacromolecules such as proteins. In this work, we present an effective and straightforward method for creating highly organized macropores within crystalline chiral metal-organic framework (CMOF) films. This approach harnesses the shaping influence of a polystyrene nanosphere template and the crystallization induced by the liquid dielectric barrier discharge plasma. The resultant highly ordered macro-microporous structures improve mass diffusion and access to chiral active sites in the hierarchical CMOF films. Coupled with their inherent chirality, strong fluorescence emission, high crystallinity, and exceptional stability, these attributes endow these CMOF films with enhanced sensing capabilities for chiral molecules. Particularly, the macro-microporous structure facilitates efficient protein recognition, overcoming a significant challenge encountered by MOFs due to protein dimensions surpassing MOF pore sizes. These films exhibit increased enantioselectivity, better limits of detection, and wider linear ranges compared with purely microporous CMOF films. This study thus provides a powerful synthetic approach for hierarchical CMOF films, addressing the limitations of traditional thin film sensors and opening an avenue for efficient chiral sensing of large biomacromolecules.

2.
Chem Commun (Camb) ; 60(80): 11237-11252, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39258376

RESUMO

Fluorescence-based chemical sensors have garnered significant attention due to their rapid response, high sensitivity, cost-effectiveness and ease of operation. Recently, metal-organic frameworks (MOFs) have been extensively utilized as platforms for constructing fluorescence sensors, owing to their ultra-high porosity, flexible tunability, and excellent luminescent properties. This feature article summarizes the progress made mainly by our research group in recent years in the construction strategies, principles, and types of MOF sensors, as well as their applications in quantitative sensing, qualitative identification analysis, and multimodal/multifunctional analysis. In addition, the challenges and an outlook on the future progression of MOF-based sensors are discussed, highlighting how these studies can contribute to addressing these issues. Hopefully, this feature article can provide some valuable guidance for the construction and application of MOFs in fluorescence sensing, thereby broadening their practical applications.

3.
ACS Appl Mater Interfaces ; 16(38): 51679-51689, 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39269944

RESUMO

In this work, a boric-acid-modified Fe3O4@Au@BA-MOF composite material as a multifunctional SERS substrate was ingeniously constructed for detecting both pathogens and antibiotics as well as photothermally inactivating the pathogens. Through improving the dispersity and stability of gold nanoparticles (Au NPs), leveraging the specificity of boric acid (BA) groups in recognizing cis-diol structures, and the ability of SERS technology to provide unique fingerprint spectra of targets, the sensitive and stable detection of pathogens and antibiotics was achieved. Compared with Au NPs and Fe3O4@Au, the SERS enhancement factor of Fe3O4@Au@BA-MOF was 4.31 × 106, which was about 400 times and 16 times higher than the former two, respectively. Among the existing work, the limit of detection for pathogens was lower or comparable, and it exhibited good stability, maintaining consistent performance for 23 days. Additionally, this substrate achieved efficient photothermal inactivation of pathogens under both near-infrared light and natural light excitation. Within 8 min of near-infrared light irradiation, the bactericidal rates for Staphylococcus aureus and Escherichia coli reach 100% and 99.3%, respectively.


Assuntos
Antibacterianos , Escherichia coli , Ouro , Análise Espectral Raman , Staphylococcus aureus , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Ouro/química , Antibacterianos/farmacologia , Antibacterianos/química , Nanopartículas Metálicas/química , Ácidos Bóricos/química , Estruturas Metalorgânicas/química , Raios Infravermelhos
4.
Anal Chem ; 96(37): 15059-15065, 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39241168

RESUMO

Herein, we report a target-triggered CRISPR/Cas12a assay by coupling lanthanide tagging and inductively coupled plasma mass spectrometry (ICP-MS) for highly sensitive elemental detection. Hepatitis B virus (HBV) DNA was chosen as a model analyte, and recombinase polymerase amplification (RPA) was used for target amplification. The double-stranded RPA amplicons containing a 5' TTTG PAM sequence can be recognized by Cas12a through a specific CRISPR RNA, activating the trans-cleavage activity of CRISPR/Cas12a and nonspecific cleavage of terbium (Tb)-ssDNA modified on magnetic beads (MBs). Following magnetic separation and acid digestion, the released Tb3+ ions were quantitated by ICP-MS and correlated to the concentration of HBV DNA. Taking advantage of the accelerated cleavage of Tb-ssDNA attached to the MB particles, RPA for target amplification, and ICP-MS for highly selective signal readout, this method permits the detection of 1 copy/µL of HBV DNA in serum with high specificity and holds great promise in the early diagnosis of viral infections or tumor development.


Assuntos
Sistemas CRISPR-Cas , DNA Viral , Vírus da Hepatite B , Elementos da Série dos Lantanídeos , Espectrometria de Massas , Vírus da Hepatite B/genética , Vírus da Hepatite B/isolamento & purificação , DNA Viral/genética , DNA Viral/análise , Elementos da Série dos Lantanídeos/química , Espectrometria de Massas/métodos , Sistemas CRISPR-Cas/genética , Humanos , Técnicas de Amplificação de Ácido Nucleico/métodos , Recombinases/metabolismo
5.
Anal Chem ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39010288

RESUMO

In this study, we utilized proteins to control the assembly of split DNAzyme to establish protein-controlled split DNAzymes (Pc SD), with the aim of enhancing its catalytic activity. To achieve this, simultaneous recognition of protein by affinity ligands at both ends of split DNAzyme fragments induced an increased local concentration of each split fragment, leading to reassembly of the split catalytic core with a rigid conformation and higher affinity to its cofactor. As a result, under protein control, Pc SD exhibits unexpected cleavage efficiency compared to free split DNAzyme. To further explore the catalytic features, we then systematically positioned split sites within the catalytic core of three popular DNAzyme-based Pc SDs, thus revealing the important nucleic acids that influence Pc SDs activity. Based on the excellent analytical performance of Pc SD for streptavidin (with a LOD of 0.1 pM in buffer),we equipped Pc SD with antibodies as rapid diagnostic tools for inpatient care (AFP as biomarker) with a minimized workflow (with a LOD of 2 pM in 5% human serum). The results of this study offer fundamental insights into external factors for boosting DNAzyme catalysis and will be promising for applications that utilize split DNAzymes.

6.
Talanta ; 278: 126531, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39002262

RESUMO

Herein, the surface-enhanced Raman scattering (SERS) platform was combined with an azo coupling reaction and an aluminum alloy covered with a hydrophobic layer of praseodymium oxide and stearic acid complexes for the detection of histamine. The praseodymium oxide on aluminum alloy was successfully synthesized by the rare-earth-salt-solution boiling bath method and modified by stearic acid. Its surface exhibits a water contact angle (WCA) of 125.0°. Through the azo derivatization reaction with 3-amino-5-mercapto-1,2,4-triazole (AMTA) diazonium salts, histamine can be converted into the derivatization product with higher Raman activity. The mixture of the derivatization product and ß-cyclodextrin-modified Ag nanoparticles (ß-CD-AgNPs) were dropped onto the surface of an aluminum alloy covered with a hydrophobic layer of praseodymium oxide and stearic acid complexes, and dried for SERS measurement. The intensity ratio between the SERS peaks at 1246 cm-1 and 1104 cm-1 (I1246/I1104) of the derivatization product was used for the quantification of histamine. Under the selected conditions, the limit of detection (LOD) and the limit of quantification (LOQ) for this method were 7.2 nM (S/N = 3) and 24 nM (S/N = 10), respectively. The relative standard deviation (RSD) of this method for the determination of 1 µM histamine was 6.1 % (n = 20). The method was also successfully used for the determination of histamine in fish samples with recoveries ranging from 92 % to 111 %. The present method is simple, sensitive, reliable, and may provide a new approach for preparing the composite hydrophobic layer that can enhance SERS signals through hydrophobic condensation effect. Meanwhile, it may have a promising future in the determination of small molecular compounds containing an imidazole ring.


Assuntos
Histamina , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas Metálicas , Prata , Análise Espectral Raman , Análise Espectral Raman/métodos , Histamina/análise , Histamina/química , Prata/química , Nanopartículas Metálicas/química , Limite de Detecção , Compostos Azo/química , Ácidos Esteáricos/química , Animais , Peixes , Propriedades de Superfície
7.
J Mater Chem B ; 12(29): 7191-7202, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-38932741

RESUMO

Unsatisfactory mechanical and antibacterial properties restricted the solo use of chitosan (CS) as a wound dressing. In this work, a novel CS/hydroxyapatite/ZIF-8 (CS/HAp/ZIF-8, CHZ-10) porous membrane was facilely constructed by in situ loading of ZIF-8 on CS/HAp. The advantages of the three compositions were rationally integrated, and the multifunctionality and practicality of this CS-based dressing were improved. HAp not only improved the mechanical strength and stability of CS, but also promoted cell proliferation and accelerated hemostasis with its released Ca2+. Meanwhile, ZIF-8 enhanced the antibacterial activity of CS by releasing antibacterial Zn2+ in a pH-responsive and sustainable manner, avoiding the bio-accumulation toxicity of heavy metals. Compared with CS/HAp and conventionally used gauze, CHZ-10 exhibited superior coagulation and hemolytic ability, as well as outstanding antibacterial activity against E. coli and S. aureus. Besides, both in vivo observation and histological evaluation demonstrated that CHZ-10 could not only effectively inhibit bacterial infection and reduce inflammation of the wound, but also promote its re-epithelialization, granulation, tissue formation and collagen fibre growth, leading to effectively enhanced wound-healing. This work provides a new method for the easy construction of multifunctional antibacterial dressings based on CS, showing promise for application in clinical wound care.


Assuntos
Antibacterianos , Quitosana , Escherichia coli , Staphylococcus aureus , Cicatrização , Quitosana/química , Quitosana/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Cicatrização/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Porosidade , Escherichia coli/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Animais , Humanos , Testes de Sensibilidade Microbiana , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Durapatita/química , Durapatita/farmacologia , Bandagens , Membranas Artificiais , Camundongos , Tamanho da Partícula , Imidazóis
8.
Chem Commun (Camb) ; 60(45): 5848-5851, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38752318

RESUMO

A dual-localized DNAzyme walker (dlDW) was constructed by utilizing multiple split DNAzymes with probes, and their substrates are separately localized on streptavidin and AuNPs, serving as walking pedals and tracks, respectively. Based on dlDW, biosensing platform was successfully constructed and showed great potential application in clinical disease diagnosis.


Assuntos
Técnicas Biossensoriais , DNA Catalítico , Ouro , Estreptavidina , DNA Catalítico/química , DNA Catalítico/metabolismo , Estreptavidina/química , Técnicas Biossensoriais/métodos , Ouro/química , Humanos , Nanopartículas Metálicas/química , Biomarcadores/análise
9.
Anal Chem ; 96(18): 7194-7203, 2024 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-38656822

RESUMO

To obtain enhanced physical and biological properties, various nanoparticles are typically assembled into hybrid nanoparticles through the binding of multiple homologous DNA strands to their complementary counterparts, commonly referred to as homomultivalent assembly. However, the poor binding affinity and limited controllability of homomultivalent disassembly restrict the assembly yield and dynamic functionality of the hybrid nanoparticles. To achieve a higher binding affinity and flexible assembly choice, we utilized the paired heteromultivalency DNA to construct hybrid nanoparticles and demonstrate their excellent assembly characteristics and dynamic applications. Specifically, through heteromultivalency, DNA-functionalized magnetic beads (MBs) and gold nanoparticles (AuNPs) were efficiently assembled. By utilizing ICP-MS, the assembly efficiency of AuNPs on MBs was directly monitored, enabling quantitative analysis and optimization of heteromultivalent binding events. As a result, the enhanced assembly yield is primarily attributed to the fact that heteromultivalency allows for the maximization of effective DNA probes on the surface of nanoparticles, eliminating steric hindrance interference. Subsequently, with external oligonucleotides as triggers, it was revealed that the disassembly mechanism of hybrid nanoparticles was initiated, which was based on an increased local concentration rather than toehold-mediated displacement of paired heteromultivalency DNA probes. Capitalizing on these features, an output platform was then established based on ICP-MS signals that several Boolean operations and analytical applications can be achieved by simply modifying the design sequences. The findings provide new insights into DNA biointerface interaction, with potential applications to complex logic operations and the construction of large DNA nanostructures.


Assuntos
DNA , Ouro , Espectrometria de Massas , Nanopartículas Metálicas , Ouro/química , DNA/química , Nanopartículas Metálicas/química
10.
Anal Chem ; 96(15): 5757-5762, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38569171

RESUMO

Uranium plays a pivotal role in the nuclear industry; however, its inadvertent release has raised concerns regarding health and environmental implications. It is crucial for a prompt warning and accurate tracing of uranium contamination in emergency scenarios. In this study, a novel and simple method was proposed that combines magnetic dispersive solid-phase extraction (MDSPE) with portable X-ray fluorescence spectrometry (XRF) for the on-site sampling and determination of trace uranium in real samples. A magnetic covalent organic framework (Fe3O4@COF) composite with excellent chemical stability and a large adsorption capacity of 311 mg/g was synthesized and employed as an efficient adsorbent for the solid-phase extraction of trace uranium. Without the need for a centrifuge or filter requirement, the established method by benchtop wavelength-dispersive X-ray fluorescence spectrometry (WDXRF) exhibits an exceptionally low limit of detection (LOD) of 0.008 µg/L with a sample volume of 50 mL and a fast adsorption time of 15 min, rendering it suitable for environmental monitoring of UO22+. Consequently, this approach, in combination with a hand-held portable XRF instrument with an LOD of 0.1 µg/L, was successfully implemented for the on-site extraction and quality assessment of real water samples, yielding accurate results and satisfactory spike recoveries.

11.
Talanta ; 274: 126039, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38604043

RESUMO

The development of intelligent, sensitive, and visual methods for the rapid detection of veterinary drug residues is essential to ensure food quality and safety. Here, a smartphone-based dual inverse signal MOFs fluorescence sensing system was proposed for intelligent in-site visual detection of malachite green (MG). A UiO-66-NH2@RhB-dual-emission fluorescent probe was successfully synthesized in one step using a simple one-pot method. The inner filter effect (IFE) quenches the red fluorescence, while hydrogen bonding interaction enhances the blue fluorescence, enabling highly sensitive, accurate, and visual detection of MG dual inverse signals through fluorescence analysis. The probe showed great linearity over a wide range of 0.1-100 µmol/L, with a limit of detection (LOD) of 20 nmol/L. By integrating smartphone photography and RGB (red, green, and blue) analysis, accurate quantitative analysis of MG in water and actual fish samples can be achieved within 5 min. This developed platform holds great promise for the on-site detection of MG in practical applications, with the advantages of simplicity, cost-effectiveness, and rapidity. Consequently, it may open up a new pathway for on-site evaluation of food safety and environmental health.


Assuntos
Corantes Fluorescentes , Corantes de Rosanilina , Smartphone , Corantes de Rosanilina/análise , Corantes de Rosanilina/química , Corantes Fluorescentes/química , Espectrometria de Fluorescência/métodos , Animais , Limite de Detecção , Fluorescência , Peixes , Poluentes Químicos da Água/análise
12.
J Am Chem Soc ; 146(11): 7594-7604, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38462726

RESUMO

The preservation of chirality during a transformation process, known as the "chiral memory" effect, has garnered significant attention across multiple research disciplines. Here, we first report the retention of the original chiral structure during dynamic covalent chemistry (DCC)-induced structural transformation from porous organic cages into covalent organic frameworks (COFs). A total of six two-dimensional chiral COFs constructed by entirely achiral building blocks were obtained through the DCC-induced substitution of chiral linkers in a homochiral cage (CC3-R or -S) using achiral amine monomers. Homochirality of these COFs resulted from the construction of 3-fold-symmetric benzene-1,3,5-methanimine cores with a propeller-like configuration of one single-handedness throughout the cage-to-COF transformation. The obtained chiral COFs can be further utilized as fluorescence sensors or chiral stationary phases for gas chromatography with high enantioselectivity. The present study thus highlighted the great potential to expand the scope of functional chiral materials via DCC-induced crystal-to-crystal transformation with the chiral memory effect.

13.
Anal Chim Acta ; 1287: 342132, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38182354

RESUMO

BACKGROUND: Recently, headspace single-drop microextraction (HS-SDME) has attracted some attention for developing sensitive and selective colorimetric assays due to its excellent capability to reduce matrix interference and enrich analytes. However, the single droplet limits direct visual observation of color change and its quantitative measurement suffers from reduced optical path length. Therefore, amplifying the detection signals in both volume and intensity is an important and challenging task for improving the sensitivity, stability, and accuracy of such colorimetric analysis. RESULTS: In this study, a "headspace-nanoenzyme" (HS-NE) strategy was proposed that successfully addressed these challenges and enabled the colorimetric and fluorescent dual-mode detection of trace Hg2+. Atomic Hg0, generated via chemical vapor generation (CVG), underwent headspace reaction with AuNPs droplet to form Au@HgNPs, thus catalyzing the oxidation of o-phenylenediamine (OPD) in the presence of H2O2. The absorbance and fluorescence intensity of oxidized OPD were proportion to the concentration of Hg2+ in the sample solution. Due to the greatly enhanced peroxidase-like activity by Au@HgNPs, the limit of detection was as low as 0.98 nM and 0.21 nM for the colorimetric and fluorescent modes, respectively. The applicability of this assay was further demonstrated with determination of Hg2+ in real environmental and biological samples. Moreover, a convenient and cost-effective paper-based sensing platform was fabricated for rapid on-site detection of Hg2+. SIGNIFICANCE AND NOVELTY: This novel HS-NE strategy combines HS-SDME and nanoenzyme-based sensing to achieve dual effects of eliminating matrix interference and amplifying the measurement signal, resulting in improved accuracy, enhanced stability, high sensitivity, and exceptional selectivity, with great potential for on-site determination of trace Hg2+.


Assuntos
Mercúrio , Nanopartículas Metálicas , Colorimetria , Ouro , Peróxido de Hidrogênio , Corantes , Peroxidases
14.
Anal Chem ; 96(1): 325-330, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38154143

RESUMO

The mechanism of selenium in the UV photochemical vapor generation (PVG) process was investigated by the use of multiple analytical methods. It was found that the UV-induced photooxidation trapping of the generated volatile SeH2 should be responsible for the previous opinion of relative inertness of Se(VI) in PVG with formic acid. Furthermore, the formation of Se(IV) was found during the PVG process, and the comproportionation of Se(IV) with SeH2 and the photooxidation of Se(IV) into Se(VI) were investigated. Then, a preliminary model was proposed for the PVG process of Se(VI) and Se(IV) with low-molecular-weight organic acids. Then, a novel, simple, and green photocontrolled method without any photocatalyst was thus proposed for the nonchromatographic speciation analysis of Se(IV) and Se(VI), with a limit of detection of 0.2 and 5 ng/mL, respectively.

15.
Chem Commun (Camb) ; 59(99): 14677-14680, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37997154

RESUMO

Combining the Hg2+-induced oxidization of silver nanoparticles with the cation exchange reaction between Ag+ and CuS nanoparticles for cascade signal amplification, a sensitive, universal and label-free ICP-MS bioassay for nucleic acids and proteins was developed. By replacing the loop sequence of the T-Hg-T hairpin structure with specific sequences or aptamers to different biomarkers, it has great promise for the early detection of biomarkers potentially for diagnosis of cancerous diseases.


Assuntos
Técnicas Biossensoriais , Mercúrio , Nanopartículas Metálicas , DNA/química , Hibridização de Ácido Nucleico , Prata/química , Nanopartículas Metálicas/química , Espectrometria de Fluorescência , Mercúrio/química , Cátions , Limite de Detecção , Biomarcadores
16.
Anal Chim Acta ; 1283: 341901, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37977772

RESUMO

BACKGROUND: Selenium is an indispensable microelement for humans and food is the main source of selenium intake. As one of the best techniques for the determination of selenium, inductive coupling plasma-mass spectrometry (ICP-MS) features some unique advantages, such as wide linear range and high sensitivity. Nevertheless, it still remains a challenge to achieve the accurate and high sensitivity determination of ultra-trace selenium in food samples by ICP-MS owning to the high first ionization energy of selenium and interferences from sample matrices as well as isobaric interferences. RESULTS: In this work, UiO-66-NH2 (metal organic framework, MOF) was fast synthesized by microwave method and employed for the preconcentration of ultra-trace selenium with an adsorption efficiency of nearly 100%. The selenium-adsorbed MOF was collected by filtration, and then simply converted to slurry for in situ hydride generation (HG) for sensitive detection of selenium by ICP-MS. Various factors affecting the adsorption of selenium by the MOF (including pH, adsorption time, and amount of MOF) together with main parameters of hydride generation (including concentrations of HCl and NaBH4) were carefully evaluated. Experimental results show that effective matrix separation can greatly reduce interference, with an excellent detection limit of 1 ng/L. The practicability and accuracy of this method were successfully confirmed by the determination of trace selenium in several food samples. SIGNIFICANCE: UiO-66-NH2 (MOF) was used as an effective adsorbent for the preconcentration of selenium prior to direct slurry sampling HG-ICP-MS determination. Direct slurry sampling avoided additional elution procedures and was conducive to eliminating matrix and isobaric interferences. High sensitivity and anti-interference determination were achieved for determination of ultra-trace Se in complex food samples.


Assuntos
Estruturas Metalorgânicas , Selênio , Humanos , Selênio/análise , Água , Espectrometria de Massas/métodos
17.
Inorg Chem ; 62(45): 18573-18582, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37917528

RESUMO

Simple and rapid synthesis of multifunctional metal-organic frameworks (MOFs) at room temperature (RT) with their multifunction controllable is still appealing for further expansion of the practical applications of MOFs. Herein, in this work, rapid RT synthesis of a multifunctional UiO-66(Ce) [M-UiO-66(Ce)] with both oxidase-like activity and fluorescence emission properties was facilely achieved within 15 min through a straightforward reactant concentration modulation and self-catalytic postmodification strategy. Appropriate concentrations of cerium ammonium nitrate or 1,4-benzenedicarboxylic acid (BDC) were beneficial for the synthesis of UiO-66(Ce) with better crystallization. During the postmodification process, through regulation of the self-photocatalysis of UiO-66(Ce), a high conversion rate from BDC to BDC-OH of up to 14% can be obtained, resulting in a significantly enhanced fluorescence signal of M-UiO-66(Ce) within 2 min. Moreover, M-UiO-66(Ce) enabled the accurate and reliable detection of tetracycline (TC) in real samples. Besides, the colorimetric and fluorescence modes complemented each other, expanding the linear range of TC detection and exhibiting its great potential for practical applications. This work provides new insights for the convenient and rapid synthesis of multifunctional materials based on MOFs, which is favorable for promoting the large-scale preparation of MOFs and their practical application in on-site environmental pollutant sensing.


Assuntos
Compostos Heterocíclicos , Estruturas Metalorgânicas , Tetraciclina , Antibacterianos , Catálise
18.
Anal Chim Acta ; 1278: 341746, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37709475

RESUMO

BACKGROUND: Inductively coupled plasma-mass spectrometry (ICP-MS) is one of the most powerful instrumental techniques for the determination of tungsten for its low detection limit and wide linear range, while it remains challenging since the analytical performance can be affected by complicated sample matrix. Chemical vapor generation (CVG) harbors the potential to be an alternative to conventional solution nebulization for sample introduction to reduce matrix effect. However, the CVG of tungsten was low in efficiency. It is clear that green and homogeneous enhancement for CVG of tungsten is desired and the mechanism is worth in-depth investigation. RESULTS: Two green and homogeneous enhancement systems for CVG of tungsten were studied, including photochemical vapor generation (PVG) and hydride generation (HG) with sensitizers, Fe3+ and DDTC, respectively. Under optimal conditions, the limits of detection (LODs) were 0.02 µg L-1 for the PVG and 0.003 µg L-1 for the HG, respectively. For PVG, the Fe3+/Fe2+ cycling, free radical species, gaseous product, and the chemical speciation evolution of W in the PVG process were studied in detail. Photo-Fenton effect, generated reductive radical ·CO2-, gaseous product Fe(CO)5, and the mixed valence of W5+/W6+ in the PVG process were found to be crucial for the enhancement. As for HG, the complexation between W(VI) and DDTC might be conducive to the enhanced HG efficiency. SIGNIFICANCE: This work not only in-depth expands the element scope of CVG, but also investigates the enhancement mechanisms experimentally, which might render a deep insight into the CVG processes and foreshadow new guidelines for screening green and efficient homogeneous sensitizers for CVGs of more elements in the future.

19.
Anal Chem ; 95(38): 14169-14174, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37712649

RESUMO

In this work, a simple and novel method coupling solid phase extraction (SPE) with X-ray fluorescence spectrometry (XRF) is proposed for the simultaneous determination of 15 kinds of trace rare earth elements (REEs) in water samples. A phosphonic acid functionalized metal-organic framework named BPG-MIL-53(Al) was prepared via postsynthetic modification and served as an efficient adsorbent for these REEs. The prepared BPG-MIL-53(Al) could almost completely adsorb REEs in 5 min under neutral conditions. After filtration, REEs-adsorbed BPG-MIL-53(Al) was deposited on a filter membrane to form a thin film, which was directly analyzed by XRF. The XRF intensities of the REEs-retained MOF disc remained almost unchanged after six months. Taking advantage of this strategy, XRF was able to quantitate ng mL-1 levels of REEs in water samples, achieving impressive limits of detection in the range of 0.4-4.7 ng mL-1. The proposed method was applied to the on-site collection and analysis of REEs in real water samples with desirable accuracy and spike recoveries obtained.

20.
J Am Chem Soc ; 145(34): 18956-18967, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37596711

RESUMO

The separation of enantiomers using high-performance chromatography technologies represents great importance and interest. In this aspect, ß-cyclodextrin (ß-CD) and its derivatives have been extensively studied as chiral stationary phases (CSPs). Nevertheless, ß-CD that was immobilized on a traditional matrix often exhibited low stabilities and limited operating ranges. Recently, covalent organic frameworks (COFs) with highly ordered nanopores are emerging as promising CSPs for enantioseparations, but their practical applications are still hampered by the difficulty of monomer and COF synthesis. Herein, two ß-CD-driven COFs are synthesized via a fast and facile plasma-induced polymerization combined postsynthesis modification strategy. The precisely defined COF channels enhanced the accessibility of the accommodated ß-CD to the analytes and acted as robust protective barriers to safeguard the ß-CD from harsh environments. Therefore, the ß-CD-modified COFs can be potentially general CSPs for extensive enantioseparation in both gas chromatography and high-performance liquid chromatography, and a wide range of racemates were separated. Compared to the commonly employed commercial chiral columns, these COF-based columns exhibited comparable resolution capability and superior application versatility. This work integrates the advantages and overcomes the defects of COFs and ß-CD, thus advancing COFs as platforms for chiral selector modification and giving great promise for practical chromatographic enantioseparation.

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