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1.
Artigo em Inglês | MEDLINE | ID: mdl-34636536

RESUMO

Although organic artificial enzymes have been reported as biomimetic oxidation catalysts and are widely used for colorimetric biosensors, developing organic artificial enzymes with high enzymatic activity is still a challenge. Two-dimensional (2D) covalent organic frameworks (COFs) have shown superior potential in biocatalysts because of their periodic π-π arrays, tunable pore size and structure, large surface area, and thermal stability. The interconnection of electron acceptor and donor building blocks in the 2D conjugated COF skeleton can lead to narrower band gaps and efficient charge separation and transportation and thus is helpful to improve catalytic activity. Herein, a donor-acceptor 2D COF was synthesized using tetrakis(4-aminophenyl)pyrene (Py) as an electron donor and thieno[3,2-b]thiophene-2,5-dicarbaldehyde (TT) as an electron acceptor. Under visible light irradiation, the donor-acceptor 2D COF exhibited superior enzymatic catalytic activity, which could catalyze the oxidation of chromogenic substrates such as 3,3',5,5'-tetramethylbenzidine (TMB) by the formation of superoxide radicals and holes. Based on the above property, the photoactivated donor-acceptor 2D COF with enzyme-like catalytic properties was designed as a robust colorimetric probe for cheap, highly sensitive, and rapid colorimetric detection of glutathione (GSH); the corresponding linear range of GSH was 0.4-60 µM, and the limit of detection was 0.225 µM. This study not only presents the construction of COF-based light-activated nanozymes for environmentally friendly colorimetric detection of GSH but also provides a smart strategy for improving nanozyme activity.

2.
Talanta ; 235: 122789, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517647

RESUMO

In this work, core-shell structured Ti4+-immobilized magnetic covalent organic frameworks (denoted as Fe3O4@TAPTDHTA-Ti4+ composites) were prepared for enhanced phosphopeptide enrichment by one-pot synthesis of COFs shell with inherent bifunctional groups on Fe3O4 NPs and further Ti4+ immobilization. The widely distributed bifunctional groups could provide abundant chelating sites for Ti4+ immobilizing. Combining with the high specific surface area and mesoporous structure, the Fe3O4@TAPTDHTA-Ti4+ composites exhibited excellent enrichment efficiency for phosphopeptides, such as low detection limit (0.05 fmol µL-1), high selectivity (1:5000 of molar ratio of ß-casein/bovine serum albumin (BSA) tryptic digests), high adsorption capacity (62.9 µg mg-1) and strong size-exclusive effect (1:250:250 of molar ratio of ß-casein tryptic digest/ß-casein/BSA). In addition, this method was general for immobilizing other metal ions (Zr4+ and Fe3+). Notably, the Fe3O4@TAPTDHTA-Fe3+ composites exhibited controllable affinity towards mono-phosphopeptides and multi-phosphopeptides. Furthermore, the Fe3O4@TAPTDHTA-Ti4+ composites were successfully applied to selectively capture phosphopeptides from complex biological samples including the tryptic digest of nonfat milk, human serum and human saliva. More significantly, 3333 phosphopeptides derived from 1409 phosphoproteins with 3492 phosphorylation sites were clearly identified from the tryptic digest of HeLa cell lysate. In addition to providing a potential excellent enrichment probe for comprehensive phosphoproteomic analysis, this study also offers a new perspective for the functionalization of COFs.


Assuntos
Estruturas Metalorgânicas , Fosfopeptídeos , Animais , Bovinos , Feminino , Células HeLa , Humanos , Fenômenos Magnéticos , Titânio
3.
Se Pu ; 39(1): 1-3, 2021 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-34435477
4.
Chem Commun (Camb) ; 57(60): 7362-7365, 2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34196343

RESUMO

A facile strategy was introduced for room-temperature controllable synthesis of hierarchically flower-like hollow COFs (FHF-COFs). Furthermore, the universality for synthesis of the HFH-COFs was validated by altering the building units. Inspired by the unique morphology, extremely large surface area and good chemical stability, HFH-COFs could serve as an attractive adsorption probe by loading with gold nanoparticles and be applied to enrichment of brain natriuretic peptide from human serum. This work opens up a whole new approach for controllable synthesis of the HFH-COFs at room temperature and expands the application of COFs as a promising enrichment probe for complex biological samples.


Assuntos
Estruturas Metalorgânicas/química , Peptídeo Natriurético Encefálico/isolamento & purificação , Adsorção , Ouro/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/química , Estruturas Metalorgânicas/síntese química , Peptídeo Natriurético Encefálico/sangue , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
5.
Talanta ; 233: 122497, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215115

RESUMO

Highly specific capture of phosphopeptides, especially multi-phosphopeptides, from complex biological samples is critical for comprehensive phosphoproteomic analysis, but it still poses great challenges due to the lack of affinity material with ideal enrichment efficiency. Here, two-dimensional (2D) covalent organic framework (COFs) nanosheets was applied for selective separation of phosphopeptides for the first time. Particularly, by incorporating guanidinium units, the 2D guanidinium-based COF nanosheets (denoted as TpTGCl CONs) exhibited controllable and specific enrichment performance towards global/multi-phosphopeptides. TpTGCl CONs was easy to prepare and showed large surface area, low steric hindrance, abundant accessible interaction sites and high chemical stability. Taking these merits together, TpTGCl CONs exhibited excellent efficiency for phosphopeptide enrichment, such as low detection limits (0.05 fmol µL-1 for global phosphopeptides and 0.1 fmol µL-1 for multi-phosphopeptides), high selectivity (1:5000 of molar ratios of ß-casein/BSA for both global and multi-phosphopeptides), high adsorption capacity (100 mg g-1 for global phosphopeptides and 50 mg g-1 for multi-phosphopeptides). Furthermore, TpTGCl CONs could be reused due to the high chemical stability. In addition, TpTGCl CONs were successfully applied to controllable and specific capture of endogenous global/multi-phosphopeptides from human serum and human saliva, indicating its good potential in rapid and sensitive detection of biomarkers from biological fluid. Finally, rat liver protein digest was used to confirm the high specificity of TpTGCl CONs towards multi-phosphopeptides and demonstrated its potential as an ideal enrichment probe for comprehensive phosphoproteomic analysis.


Assuntos
Estruturas Metalorgânicas , Fosfopeptídeos , Adsorção , Cromatografia de Afinidade , Guanidina , Titânio
6.
Chem Commun (Camb) ; 57(61): 7501-7504, 2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34259250

RESUMO

Micron-sized spherical covalent organic frameworks (SCOFs) with tunable sizes, narrow size distribution, and significant mono-dispersity were simply synthesized at room temperature. Thanks to their high specific surface areas, high chemical and mechanical stability, the SCOFs were used for the first time as stationary phases for high-efficiency separation of various small molecules and protein digests via short-column liquid chromatography.

7.
J Chromatogr A ; 1651: 462329, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34157477

RESUMO

Efficiently tunable capture of the glycosylated/phosphorylated proteins is critical to meet the need of in-depth glycoproteome and phosphoproteome studies. Reported here is a new bifunctional polymer monolithic column by introducing benzeneboronic acid and phosphonic acid onto monolithic column (denoted as poly (EDMA-co-VPBA-co-VPA) monolith) for tunable and specific enrichment of glycoproteins and phosphoproteins via switching different mobile phases. Based on boronate affinity and immobilized metal affinity, the as-prepared poly (EDMA-co-VPBA-co-VPA) monolith exhibited superior performance in selective separation of small molecules and biomacromolecules containing cis-diol/phosphate groups or not. And the frontal chromatography analysis showed that the binding capacity of the poly (EDMA-co-VPBA-co-VPA) monolith towards horseradish peroxidase (HRP, glycoprotein) or ß-casein (phosphoprotein) is four-fold higher than that of bovine serum albumin (BSA, non-glycosylated/phosphorylated protein). Furthermore, combined with mass spectrometry identification, the successful application in specific enrichment of glycopeptides/phosphopeptides from tryptic digests of HRP/ß-casein and direct capture of low abundant endogenous phosphopeptides from human serum proved great practicability in complex samples. This study provides a novel insight for fabricating the monolithic columns with multifunctionalization to facilitate further post-translational modification (PTM)-proteomics development.


Assuntos
Análise Química do Sangue/instrumentação , Cromatografia/instrumentação , Glicoproteínas/isolamento & purificação , Fosfoproteínas/isolamento & purificação , Polímeros/química , Ácidos Borônicos/química , Caseínas/metabolismo , Glicopeptídeos/isolamento & purificação , Peroxidase do Rábano Silvestre/metabolismo , Humanos , Fosfopeptídeos/química , Ácidos Fosforosos/química , Soroalbumina Bovina/isolamento & purificação
8.
Analyst ; 146(9): 2991-2997, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33949450

RESUMO

A spherical thiol-functionalized covalent organic framework (COF-SH) was designed via a facile thiol-yne click reaction of a alkynyl-terminated COF and pentaerythritol tetra(3-mercaptopropionate). The COF-SH was explored as a new adsorbent for the selective enrichment of Hg2+. The as-prepared COF-SH exhibited a uniform mesoporous structure, a high abundance of binding sites, and good chemical stability, which endow it with great performance for the adsorption of Hg2+ and its corresponding maximum adsorption capacity was up to 617.3 mg g-1. Furthermore, the adsorption behavior of Hg2+ on the COF-SH wasin good agreement with the Langmuir and pseudo-second-order models. The influences of adsorbent dosage, pH, selectivity, and reusability of the COF-SH on Hg2+ adsorption were also investigated. Besides this, the COF-SH showed high selectivity towards Hg2+ even in the presence of a high concentration of K+, Na+, Ca2+, Mg2+ and Zn2+ metal ions. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), the corresponding limit of detection (LOD) of Hg2+ was determined at very low concentrations of 80 pg mL-1 (equal to 396 amoL µL-1). In addition, the COF-SH was successfully applied to rapidly enrich and sensitively detect Hg2+ in industrial sewage, with recoveries in the range of 101.8-103.4%, demonstrating the promising potential of COF-SH as an effective adsorbent for use in environmental sample pretreatment.

9.
Mikrochim Acta ; 188(5): 150, 2021 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-33813605

RESUMO

Ti4+-immobilized hierarchically porous zirconium-organic frameworks (denoted as THZr-MOFs) was prepared for phosphopeptide enrichment. The THZr-MOFs showed high specific surface area of 185.28 m2 g-1, wide pore-size distribution of 3 ~ 20 nm, good chemical stability and excellent hydrophilicity. Introduction of hierarchical pores in MOFs not only facilitated the accessibility of phosphopeptides to the internal metal affinity sites and reduce their mass transfer resistance, but also increased the exposure sites of metal affinity interaction and binding energies of Zr and Ti elements. Benefited from these advantages, the THZr-MOFs showed high adsorption capacity (79.8 µg mg-1) towards standard phosphopeptide. A low detection limit (0.05 fmol µL-1) and high enrichment selectivity (ß-casein/BSA with a molar ratio of 1:5000) were also obtained by MALDI-TOF MS. The THZr-MOFs were applied to analyze complex samples including nonfat milk, human serum, and HeLa cell lysate. In total, 1432 phosphopeptides derived from 762 phosphoproteins were identified from human HeLa cell lysate. Schematic representation of the application of Ti4+-immobilized hierarchically porous zirconium-organic frameworks (denoted as THZr-MOFs) in high-efficiency and selective enrichment of low-abundance phosphopeptides from the tryptic digest of human HeLa cell lysate.

10.
J Hazard Mater ; 411: 125190, 2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-33858120

RESUMO

Frequent oil-spill accidents not only cause serious and long-term damage to marine ecosystems, but also lead to a huge loss of valuable natural resources. To lighten the environmental pollution of oil spills as quickly as possible, an efficient and environment-friendly approach for oil-water separation is highly desirable. Herein, a facile one-pot room-temperature approach was developed for large-scale fabrication of covalent organic framework-coated superhydrophobic sponges (sponges@COFs). The as-prepared sponges@COFs possessed many superior properties, including superhydrophobicity with the water contact angle of approximately 154.3°, large specific surface area (153.059 m2/g), high porosity of the network structures, as well as good mechanical and chemical stability. Taking the aformentioned advantages together, the superhydrophobic sponges showed ultra-high adsorption capacity for oil and various organic solvents. In comparision with its own weight, the adsorption amount of the sponges@COFs for silicone oil was up to 150 times and for toluene was 125 times, respectively. Furthermore, the superhydrophobic sponges also showed fast and highly efficient oil-water separation, outstanding flame retardancy and recyclability. In addition, the sponges@COFs were successfully applied to the high-efficiency removal of oil suspension from industrial waste water, firmly confirming their application prospect in industrial wastewater treatment.

11.
Mikrochim Acta ; 188(3): 91, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33598812

RESUMO

Magnetic covalent organic frameworks (Fe3O4@TPPCl4) were synthesized via a one-pot process in which magnetic nanoparticles (Fe3O4@MNP) served as a magnetic core and 2,4,6-trihydroxy-1,3,5-benzenetricarbaldehyde (TP) and 2,2',5,5'-tetrachlorobenzidine (PCl4) as two building blocks to form a shell. The as-prepared Fe3O4@TPPCl4 nanoparticles have superior features, including large surface area (186.5 m2 g-1), high porosity, strong magnetic responsiveness (42.6 emu g-1), high chlorine content, and outstanding thermal stability, which make them an ideal adsorbent for highly selective enrichment of polychlorinated naphthalenes (PCNs). Combining with atmospheric pressure gas chromatography tandem mass spectrometry (APGC-MS/MS), a simple analytical method of Fe3O4@TPPCl4-based magnetic solid-phase extraction (MSPE)-APGC-MS/MS was developed, which exhibited good linearity (r ≥ 0.9991) for eight PCNs in the concentration range 0.1-100 ng L-1. Moreover, low detection limits (0.005-0.325 ng L-1), high enrichment factors (46.62-81.97-fold), and good relative standard deviations (RSDs) of inter-day (n = 3, 1.64 to 7.44%) and day-to-day (n = 3, 2.62 to 8.23%) were achieved. This method was successfully applied to the selective enrichment of PCNs in fine particulate matter (PM)2.5 samples, and ultra-trace PCNs were found in the range 1.56-3.75 ng kg-1 with satisfactory recoveries (93.11-105.81%). The successful application demonstrated the great potential of Fe3O4@TPPCl4 nanoparticles as an adsorbent for enrichment of halogenated compounds. Schematic presented one-pot synthesis of magnetic covalent organic framework nanocomposites (Fe3O4@TPPCl4) and their application in the selective enrichment of PCNs from PM2.5 prior to APGC-MS/MS analysis.

12.
Analyst ; 146(5): 1543-1547, 2021 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-33565552

RESUMO

4-Mercaptobenzoic acid (MBA) is introduced as a matrix for laser desorption/ionization time-of-flight mass spectrometry (MS) analysis of metals, exhibiting matrix-interference-free background, greatly enhanced MS signal intensity, and excellent reproducibility. The developed method was successfully extended for the rapid screening and sensitive determination of ultratrace metals in fine particulate matter (PM2.5).

13.
J Chromatogr A ; 1635: 461742, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33254000

RESUMO

Fast and highly efficient digestion of proteins is essential for high-throughput proteomic analysis. Herein, a facile approach was developed for self-assembly preparation of trypsin-immobilized capillary monolithic column and its application as an immobilized enzyme microreactor (IMER) for fast and highly efficient proteolysis was described. The performance of the trypsin-immobilized monolithic enzyme microreactor was evaluated by in-situ digestion of model proteins. The results showed that the trypsin-immobilized monolithic enzyme microreactor had much higher tryptic digestion efficiency than the free trypsin in solution, where the coverage of peptide sequences by mass spectrometry (MS)-based analysis could bear comparison with the free one, while the digestion time was dramatically shortened from 12 h to 16 s. Furthermore, the trypsin-immobilized monolithic enzyme microreactor also exhibited good practicability to complex human serum sample, in which the total of 45 peptides from human serum albumin (HSA) matched with sequence coverage of 75% were precisely identified. The successful application demonstrated the promising potential of the trypsin-immobilized capillary monolithic column as the IMER in high-throughput proteomic analysis.


Assuntos
Reatores Biológicos , Proteólise , Proteômica/métodos , Tripsina/metabolismo , Proteínas Sanguíneas/metabolismo , Enzimas Imobilizadas/química , Humanos , Espectrometria de Massas , Peptídeos/metabolismo
14.
Talanta ; 221: 121651, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33076167

RESUMO

Polybrominated diphenyl ethers (PBDEs), known as the most widely used brominated flame retardant, have received great public concern due to its hidden environment and health problems. Development of highly selective and sensitive analytical approaches for enrichment and detection of ultratrace PBDEs are in high demand. Conventional sample pretreatment techniques usually require tedious procedures, long time, and excessive consumption of solvent and sample, thus hindering ultrasensitive detection of PBDEs. To address this issue, we first reported a simple room-temperature approach for synthesis of tubular magnetic fluorinated covalent organic frameworks (MCNT@TAPB-TFTA). The introduction of fluorine atoms played multiple roles in improving the frameworks' hydrophobicity and the adsorption capabilities for PBDEs. Combined with atmospheric pressure gas chromatography-tandem mass spectrometry (APGC-MS/MS), several crucial parameters of magnetic solid-phase extraction (MSPE) including adsorbent dosage, adsorption time, pH, ion strength, the eluent, elution time and elution frequencies were examined in detail. The optimal method exhibited wide linear ranges (0.01-500 ng/L), low limit of detections (LODs, 0.0045-0.018 ng/L), good correlation coefficients (r ≥ 0.9977), and high enrichment factors (EFs, 1425-1886 folds) for eight PBDEs. Furthermore, this proposed method could be successfully applied to sensitive determination of ultratrace PBDEs in environmental samples, demonstrating the promising potential of the MCNT@TPAB-TFTA as an adsorbent in sample pretreatment.

15.
Analyst ; 145(16): 5664-5669, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32643716

RESUMO

Polydopamine nanospheres (PDA) were designed to serve as a new substrate for surface-enhanced desorption/ionization mass spectrometry (SELDI-MS). Compared with conventional organic matrices, the PDA substrate showed superior LDI performance for analyzing a wide variety of environmental pollutants, including polycyclic aromatic hydrocarbons, bisphenols, benzophenones, sulfonamides, perfluorinated compounds and estrogens. Benzoapyrene was used to evaluate the ability of quantitative analysis and its corresponding limit of detection (LOD) of as low as 0.1 ng was achieved. High sensitivity and good reproducibility of PDA-based SELDI-MS allowed us to determine ultratrace PAHs in airborne particulate matters (PM2.5), and the corresponding concentration of BaP in different PM2.5 were 5.32, 8.97 and 9.79 ng m-3. Significantly, PDA exhibits the characteristics of simple synthesis, low cost, non-toxicity and less matrix interference, which provides the possibility for the sensitive analysis of organic small molecule pollutants at low concentrations in complex environmental samples.

16.
Mikrochim Acta ; 187(7): 370, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32504203

RESUMO

Core-shell structured magnetic covalent organic framework (Fe3O4@COF) nanospheres were rapidly synthesized at room temperature using the monodisperse Fe3O4 nanoparticles (NPs) as magnetic core and benzene-1,3,5-tricarbaldehyde (BTA) and 3,3'-dihydroxybenzidine (DHBD) as two building blocks (denoted as Fe3O4@BTA-DHBD), respectively. They can serve as a mass spectrometry probe for rapid and high-throughput screening of bisphenols (BPs) from pharmaceuticals and personal care products (PPCPs) by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). The Fe3O4@BTA-DHBD nanospheres showed some superior features involving average pore size distribution (2.82 nm), high magnetization values (42.5 emu g-1), high specific surface area (82.96 m2 g-1), and good chemical/thermal stability. It was used as both ideal adsorbent for enrichment of BPs and new substrate to assist ionization in SELDI-TOF-MS. The method exhibited good linearity in the range 0.05-4000 ng mL-1 with correlation coefficients (r) higher than 0.9920. Low limits of detection (LODs) (500 pg mL-1 for bisphenol A (BPA), 2 pg mL-1 for bisphenol B (BPB), 28 pg mL-1 for bisphenol C (BPC), 60 pg mL-1 for bisphenol F (BPF), 33 pg mL-1 for bisphenol AF (BPAF), 200 pg mL-1 for bisphenol BP (BPBP), 10 pg mL-1 for bisphenol S (BPS), 90 pg mL-1 for tetrabromobisphenol A (BPA(Br)4), and 380 pg mL-1 for tetrabromobisphenol S (BPS(Br)4)) and good recoveries (80.6-115%) of BPs in PPCPs were achieved. The relative standard deviations (RSDs) of spot-to-spot (n = 10) and sample-to-sample (n = 5) were in the ranges 5-11% and 5-12%, respectively. The dual-function platform was successfully applied to the quantitative determination of BPs in PPCPs. It not only expanded the scope of the application of COFs but also provided an alternative strategy for the determination of hazardous compounds in PPCPs. Graphical abstract Schematic representation of the synthesis of core-shell structured magnetic covalent organic framework nanospheres (Fe3O4@COFs) and its application in the analysis of bisphenols by using Fe3O4@BTA-DHBD nanospheres as a MS probe based on surface-enhanced laser desorption/ionization time-of-flight mass spectrometry.

17.
J Mater Chem B ; 8(21): 4642-4647, 2020 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-32373807

RESUMO

Immobilization of enzymes onto metal-organic frameworks (MOFs) through a biomimetic mineralization approach can preserve biological functionality in harsh environments. Despite the success of this approach, the alkaline environment of the reaction system, which is caused by the organic monomers of MOFs, makes it unsuitable for some pH-sensitive enzymes, especially for trypsin. Herein, we reported a facile approach for the one-pot synthesis of trypsin-immobilized magnetic zeolite imidazolate framework-8 (iron oxide@ZIF-8@trypsin), where the growth of ZIF-8 around the citric acid-modified iron oxide and immobilization of trypsin occurred simultaneously when the pH of the reaction system was changed to some extent. With a large specific surface area and a high enzyme loading capacity, the resultant iron oxide@ZIF-8@trypsin exhibited 2.6 times higher enzymatic activity than free trypsin. Moreover, it showed a favourable magnetic response (43 emu g-1) which made the operation and recycling easy and convenient. In addition, iron oxide@ZIF-8@trypsin could be applied as an immobilized enzyme microreactor (IMER) to rapidly and efficiently digest proteins and complex human serum samples with satisfactory results, showing great promise for application in proteomic analysis.


Assuntos
Citocromos c/metabolismo , Peroxidase do Rábano Silvestre/metabolismo , Estruturas Metalorgânicas/metabolismo , Proteólise , Soroalbumina Bovina/metabolismo , Tripsina/metabolismo , Animais , Bovinos , Ácido Cítrico/química , Ácido Cítrico/metabolismo , Citocromos c/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Peroxidase do Rábano Silvestre/química , Humanos , Imidazóis/química , Imidazóis/metabolismo , Nanopartículas Magnéticas de Óxido de Ferro/química , Estruturas Metalorgânicas/química , Tamanho da Partícula , Soroalbumina Bovina/química , Propriedades de Superfície , Tripsina/química , Zeolitas/química , Zeolitas/metabolismo
18.
Analyst ; 145(8): 3125-3130, 2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32163066

RESUMO

A spherical vinyl-functionalized covalent-organic framework (COF-V) was prepared at room temperature by a facile method and applied as a novel substrate for surface-enhanced laser desorption/ionization mass spectrometry (SELDI-MS). Compared with conventional organic matrices, the spherical COF-V with high crystallinity and good monodispersity exhibited high sensitivity, no matrix background interference, wide-range applicability, high salt tolerance and reproducibility in the characterization of small molecules. Considering these advantages, the applicability of the spherical COF-V-based SELDI-MS method was successfully demonstrated by determining trace amounts of glucose in diabetic urine, which would be a promising candidate for clinical diagnosis of diabetes. In addition, the morphological effect and the desorption/ionization mechanism of the COF-V were investigated in detail and the results indicated that the spherical COF-V substrate could greatly enhance the LDI process compared with the bulk COF-V. This work not only extends the application of COFs in MS, but also offers a promising alternative for small molecule identification and clinical diagnosis of diabetes.


Assuntos
Estruturas Metalorgânicas/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Diabetes Mellitus/diagnóstico , Poluentes Ambientais/análise , Glucose/análise , Glicosúria/diagnóstico , Humanos , Limite de Detecção , Compostos Orgânicos/análise , Reprodutibilidade dos Testes
19.
Anal Chim Acta ; 1100: 66-74, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31987154

RESUMO

Short-chain fatty acids (SCFAs) and hydroxylated short-chain fatty acids (OH-SCFAs) are crucial intermediates related to a variety of diseases, such as bowel disease, cardiovascular disease, renal disease and cancer. A global profiling method to screen SCFAs and OH-SCFAs was developed by tagging these analytes with d0/d6-N, N-dimethyl-6,7-dihydro-5H-pyrrolo [3,4-d] pyrimidine-2-amine (d0/d6-DHPP) and using ultra-high performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UHPLC-MS/MS) in parallel reaction monitoring (PRM) mode. The derivatization procedure was simple and rapid. The targeted compounds could be derivatized within 3 min under mild condition and analyzed without the need of further purification. The derivatization significantly improved the chromatographic performance and mass spectrometry response. The d6-DHPP tagged standards were used as internal standards, which remarkably reduced the matrix effects. The use of high resolution PRM mode made it possible to locate unknown SCFA and OH-SCFA species, and greatly reduced the false positive identification results. The developed method was successfully applied to the analysis of mouse fecal, serum, and liver tissue samples harvested from the breast cancer nude mice that had been exposed with 2,2',4,4'-tetrabromodiphenyl ether (BDE-47). Results showed that 40 analytes (10 SCFAs and 30 OH-SCFAs) were characterized. Semi-quantitative analysis indicated that the exposure of BDE-47 to the mice altered the SCFA and OH-SCFA metabolism, especially in the high dose group. This study provides a high-throughput method to characterize SCFAs and OH-SCFAs in mouse samples.


Assuntos
Neoplasias da Mama/química , Ácidos Graxos Voláteis/análise , Animais , Neoplasias da Mama/induzido quimicamente , Neoplasias da Mama/diagnóstico , Cromatografia Líquida de Alta Pressão , Modelos Animais de Doenças , Feminino , Éteres Difenil Halogenados , Humanos , Hidroxilação , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Espectrometria de Massas em Tandem , Células Tumorais Cultivadas
20.
J Chromatogr A ; 1615: 460773, 2020 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-31839356

RESUMO

Perfluorinated compounds (PFCs) are new types of persistent organic pollutants known to bioaccumulate in organism, which have come under increased scrutiny due to the close relation with various health problems. Sensitive detection of PFCs remains a significant challenge because of their ultratrace levels in complex samples. Herein, fluorinated magnetic covalent organic frameworks (Fe3O4@TpPa-F4) were first synthesized via a monomer-mediated in situ growth strategy and served as fluorinated magnetic adsorbent. Accordingly, a novel pretreatment method based on fluorinated magnetic solid-phase extraction (FM-SPE) combined with HPLC-MS/MS was developed to detect ultratrace PFCs from milk samples. The as-prepared Fe3O4@TpPa-F4 possessed regular porosity (0.81 nm) with large surface areas (188.04 m2/g), high fluorine content (4.85%), strong magnetic responsiveness (50 emu/g), and good chemical and thermal stability, which rendered it an ideal adsorbent material for highly efficient extraction of PFCs. Under the optimized parameters, the developed method displayed good linearity for six PFCs in the range of 0.1-250 ng/L with high correlation coefficients (r ≥ 0.9952), and the corresponding limits of detection (LODs) were 0.005-0.05 ng/L (S/N ≥ 3). Furthermore, high enrichment factors (EFs, 21.91-100.6 folds) and acceptable relative standard deviations (RSDs) of inter-day (0.5-11.8%) and batch-to-batch (2.3-11.7%) for the six PFCs were achieved. Moreover, this method was further employed to milk samples with different brands and packages, in which ultratrace PFCs were found with diverse concentrations from 10.36 to 729.34 ng/L, confirming the promising applicability of the Fe3O4@TpPa-F4 as an alternative adsorbent for sample pretreatment.


Assuntos
Fluorcarbonetos/análise , Análise de Alimentos/métodos , Estruturas Metalorgânicas/síntese química , Leite/química , Extração em Fase Sólida , Animais , Cromatografia Líquida de Alta Pressão , Flúor/química , Limite de Detecção , Magnetismo , Espectrometria de Massas em Tandem
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