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1.
Anal Chem ; 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34637621

RESUMO

Sensitive and precise determination of chloramphenicol (CAP) is of great significance for human health due to its high risk in trace amounts. Solid-state artificial nanochannels are expected to be highly promising sensing devices owing to single-molecule sensitivity, target-specific selectivity, and portability. Herein, we report an aptamer self-assembly-functionalized artificial nanochannel-based sensor for highly sensitive and precise determination of CAP. Aptamer self-assembly (AAs) served as the specific recognition component and were in situ grown on the surface of stable anodic aluminum oxide (AAO) nanochannels to develop an AAs@AAO nanochannel-based sensor. Selective interaction with CAP led to the disassembly of AAs and sensitive current change of AAs@AAO nanochannels, allowing sensitive and precise sensing of CAP in complex food samples. The developed AAs@AAO nanochannel-based sensor showed a wide linear range from 0.32 to 1600 pg. mL-1, low limit of detection (LOD) of 0.1 pg. mL-1, high precision with relative standard deviation of 2.9%, and quantitative recoveries of 93.4-102.2% for CAP in milk, milk powder, and honey samples. This work proposes a versatile nanochannel-based platform for facile, sensitive, and precise sensing of hazardous residues in food samples.

2.
J Hazard Mater ; 416: 125860, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492808

RESUMO

Facile synthesis of nano porous organic cages with small size and good fluorescence property is highly desirable, but still challenging and scarce for their sensing applications. Here we report a rapid room-temperature recrystallization method for the preparation of nano porous organic cages with ultra-small size as a fluorescent probe for copper ion. The prepared nano porous organic cages gave the diameter of 2.49 ± 0.04 nm, and exhibited stable emission at 535 nm with absolute quantum yield of 0.68%. On the basis of the coordination interaction and charge transfer between the nano porous organic cages and copper ion, a simple fluorescent probe for copper ion in aqueous solution was developed. The developed method gave a calibration function of QE = 0.4815lg[Cu2+] + 0.5847 (where QE is the quenching efficiency; [Cu2+] in µM) (R2 = 0.9987) in a concentration range of 0.1-2 µM, the limit of detection (3s) of 8 nM, and the relative standard deviation of 0.36% for 10 replicate determinations of 0.5 µM copper ion. The recoveries of spiked copper ion in tap water samples ranged from 96.8% to 103.0%. The proposed method possesses good sensitivity, selectivity and accuracy.


Assuntos
Cobre , Água , Fluorescência , Corantes Fluorescentes , Porosidade , Espectrometria de Fluorescência , Temperatura
3.
Talanta ; 233: 122536, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215039

RESUMO

Preparation of porphyrin-based covalent organic frameworks (Por-COFs) with high photosensitizing activity for photodynamic inactivation of bacteria is of great challenge, but significant for economy and human health. Herein, we show a conjugation-regulating strategy to design and synthesize Por-COFs with high photosensitizing activity for the photodynamic inactivation of bacteria. Terephthalaldehyde (Da), 2,5-Dihydroxyterephthalaldehyde (Dha), and 2,5-Diethoxyterephthalaldehyde (Deta) with different conjugation degrees are selected to condense with 5,10,15,20-Tetrakis(4-aminophenyl)porphyrin (Tph) to synthesize COF-366, DhaTph, and JNU-2, respectively. The higher conjugation of Dha and Deta than Da leads to the higher conjugation of DhaTph and JNU-2, respectively. Moreover, the hydroxyl group in Dha and the ethoxy group in Deta further expand the conjugation of DhaTph and JNU-2 via the formation of intralayer extended π-cloud delocalization and p-π conjunction, respectively. The extension of conjugation for DhaTph and JNU-2 results in the increase of intersystem crossing process and significantly improves their photosensitizing activity. Furthermore, JNU-2 with the highest photosensitizing activity exhibits superior antibacterial effects toward Staphylococcus aureus (99.1%) and Escherichia coli (96.8%). This study offers a new conjugation-regulating strategy for designing high photosensitizing activity of Por-COFs for the inactivation of bacteria.


Assuntos
Estruturas Metalorgânicas , Porfirinas , Antibacterianos/farmacologia , Humanos , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/farmacologia , Staphylococcus aureus
4.
Talanta ; 233: 122567, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215063

RESUMO

Photodynamic therapy (PDT) received great attention in cancer therapy due to the advantages of negligible drug resistance, low side effects, and minimal invasiveness. Development of theranostic nanoprobes with specific imaging-guided PDT is of great significance in the field. Herein we report the fabrication of a novel theranostic nanoprobe porphyrin/G-quadruplex conjugated gold/persistent luminescence nanocomposites for imaging-guided PDT. The developed nanoprobe contains NIR-emitting persistent luminescent nanoparticles (PLNP) as the core for autofluorescence-free bioimaging and Au coating on PLNP for facile subsequent DNA conjugation. The DNA sequence is designed to contain G-rich AS1411 aptamer for recognizing the over-expressed cellular nucleolin of cancer cell and forming a G-quadruplex structure to combine with tetrakis (4-carboxyphenyl) porphyrin (TCPP) to realize PDT. The AS1411 aptamer-contained DNA conjugated Au-coated PLNP is rapidly prepared via a freezing method with high content of DNA and good aqueous stability. Meanwhile, TCPP is easily loaded into the G-quadruplex structure formed from G-rich AS1411 aptamer on the surface of Au/PLNP in presence of K+. The theranostic nanoprobe gives integrated merits of PLNP for autofluorescence-free bioimging, TCPP for PDT and AS1411 aptamer-contained DNA for specific binding to cancer cells. This work provides a new specially designed imaging-guided PDT nanoplatform for theranostics.


Assuntos
Fotoquimioterapia , Porfirinas , Linhagem Celular Tumoral , Ouro , Luminescência , Medicina de Precisão
5.
Anal Bioanal Chem ; 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34331090

RESUMO

The separation of amino acid (AA) enantiomers shows significance for chemistry, food, and biology, but remains challenging due to their similar properties. A promising nanoporous chiral covalent organic framework (COF) as a stationary phase for high-performance liquid chromatography (HPLC) suffers from the irregularity and widely distributed particle size of the chiral COF. Herein, we show the facile preparation of a chiral COF-monolith as a stationary phase for HPLC enantiomeric separation of AAs via orthogonal experiments. The CTzDa-monolith is prepared by the incorporation of the model chiral COF named CTzDa into the porous poly(ethylene dimethacrylate-co-methacrylate) monolith and reveals great permeability and mechanical stability. The corresponding CTzDa-monolithic column gives better chiral HPLC separation of AAs than the commercial Poroshell 120 chiral-T column. Thermal dynamic analysis and molecular docking calculations imply the involvement of stereoscopic hydrogen, π-π, and van der Waals interactions between the CTzDa and AAs during HPLC enantioseparation. The facile incorporation of the chiral COF into the porous monolith will promote the potential of a chiral COF as a stationary phase for HPLC.

6.
Angew Chem Int Ed Engl ; 59(40): 17607-17613, 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32497359

RESUMO

Design of stable adsorbents for selective gold recovery with large capacity and fast adsorption kinetics is of great challenge, but significant for the economy and the environment. Herein, we show the design and preparation of an irreversible amide-linked covalent organic framework (COF) JNU-1 via a building block exchange strategy for efficient recovery of gold. JNU-1 was synthesized through the exchange of 4,4'-biphenyldicarboxaldehyde (BA) in mother COF TzBA consisting of 4,4',4''-(1,3,5-triazine-2,4,6-triyl)trianiline (Tz) and BA with terephthaloyl chloride. The irreversible amide linked JNU-1 gave good stability, unprecedented fast kinetics, excellent selectivity and outstanding adsorption capacity for gold recovery. X-ray photoelectron spectroscopy along with thermodynamic study and quantum mechanics calculation reveals that the excellent performance of JNU-1 for gold recovery results from the formation of hydrogen bonds C(N)-H⋅⋅⋅Cl and coordinate interaction of O and Au. The rational design of irreversible bonds as both inherent linkage and functional groups in COFs is a promising way to prepare stable COFs for diverse applications.

7.
Chempluschem ; 85(5): 828-831, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32364333

RESUMO

Development of efficient adsorbents for nitrate removal is vital for tackling increasing nitrate contamination. We report a free-radical polymerization strategy to prepare a cationic surfactant-modified covalent organic framework (DhaTab-S) for removing nitrate ions from aqueous solution. DhaTab-S was prepared by grafting a cationic surfactant diallyldimethylammonium chloride solution on vinyl-containing COF (DhaTab-V). The adsorption capacity for nitrate was pH-dependent with the maximum at pH 6, and the adsorption process was largely influenced by ionic strength. The adsorption equilibrium for nitrate on DhaTab-S was reached within 40 minutes and followed pseudo-second-order kinetics. DhaTab-S showed a nitrate adsorption capacity of 108.8 mg g-1 , which is about 15 times that of COF before surfactant modification. The large adsorption capacity makes DhaTab-S a promising candidate for nitrate removal from aqueous media.

8.
ACS Appl Mater Interfaces ; 11(49): 46219-46225, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31738503

RESUMO

We report a thiol-ene click strategy for the preparation of a novel phenylboronic acid-functionalized covalent organic framework (COF) for selective removal of catechol in aqueous solution. Vinyl-functionalized 2,5-diallyloxyterephthalaldehyde (Da-V) was prepared as a building ligand. Da-V was then condensed with 1,3,5-tris(4-aminophenyl)benzene (Tab) to give a vinyl-functionalized COF DhaTab-V. Subsequently, 4-mercaptophenylboronic acid (4-MPBA) was covalently linked on DhaTab-V via thiol-ene click reaction to give phenylboronic acid-functionalized COF DhaTab-PBA. The adsorption isotherms, energetics and kinetics, and reusability of DhaTab-PBA for the adsorption and removal of catechol from aqueous solution were investigated in detail. This phenylboronic acid-functionalized COF is promising as sorbent for selective removal of catechol from aqueous medium with large adsorption capacity and good reusability.

9.
Anal Chem ; 91(20): 13191-13197, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31522496

RESUMO

Aflatoxin B1 (AFB1) contamination is one of the most critical global issues in food safety. The high carcinogenic nature necessitates rapid and specific methods for the determination of AFB1 in foodstuffs at ultratrace levels. Here, we report an enhanced bienzymatic chemiluminescence competitive immunoassay for ultrasensitive and high-throughput determination of AFB1. In this assay, protein G was first coated on the wells of a microplate for recognizing the Fc fragment of anti-AFB1 mAbs to reduce the antibody dosage and guarantee high immunological reaction efficiency. The target AFB1 competed with glucose oxidase labeled AFB1 for the limited anti-AFB1 mAbs in the wells of the microplate. p-Bromophenol was employed as an enhancer to obtain intense and long-lasting chemiluminescence. The utilization of an enhancer and bienzymatic catalysts effectively improved the detection sensitivity. The developed method offered a good linearity over 5 orders of magnitude, a detection limit of 5 pg L-1, and a relative standard deviation of 1.9% for AFB1. The application of the developed method to the analysis of grain samples gave quantitative recoveries from 94.0% to 97.0%. The developed method provides a universal platform for high-throughput, ultrasensitive, and high specific detection of pollutants or nutrients in foods.


Assuntos
Aflatoxina B1/análise , Contaminação de Alimentos/análise , Imunoensaio/métodos , Medições Luminescentes/métodos , Fenóis/química , Aflatoxina B1/imunologia , Anticorpos Imobilizados/imunologia , Anticorpos Monoclonais/imunologia , Armoracia/enzimologia , Proteínas de Bactérias/química , Grão Comestível/microbiologia , Glucose Oxidase/química , Peroxidase do Rábano Silvestre/química , Limite de Detecção , Substâncias Luminescentes/química , Luminol/química
10.
Talanta ; 204: 224-228, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357286

RESUMO

Gold nanoparticles (AuNPs) without surface capping agents are easily aggregated owing to their high surface energy, leading to an unexpected decrease of their catalytic activity. Herein, we report gold nanoparticles decorated covalent organic framework (COF) as mimetic peroxidase for colorimetric detection of mercury. 1,3,5-Tris-(4-formyl-phenyl)triazine (PT) and 4, 4'-azodianiline (Azo) was employed as the monomers to prepare a novel imine based COF PTAzo under solvothermal conditions. AuNPs are further decorated into the PTAzo to form COF-AuNPs hybrid via a citrate reducing method. The COF-AuNPs show high stability, and exhibits enhanced peroxidase mimetic activity in the presence of Hg2+. The Hg2+ concentration dependent peroxidase mimetic activity of COF-AuNPs enables the development of a sensitive and selective method for detection of Hg2+ in aqueous solution. The developed method gives good linearity in the range of 5-300 nM with the limit of detection of 0.75 nM. The results show that Hg2+-enhanced peroxidase mimetic activity of COF-AuNPs offers great potential for the detection of Hg2+ in real samples.

11.
Cancer Cell Int ; 19: 162, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31210753

RESUMO

Background: AT-rich interactive domain-containing protein 1A (ARID1A) is a subunit of the mammary SWI/SNF chromatin remodeling complex and a tumor suppressor protein. The loss of ARID1A been observed in several types of human cancers and associated with poor patient prognosis. Previously, we have reported that ARID1A protein was rapidly ubiquitinated and destructed in gastric cancer cells during DNA damage response. However, the ubiquitin e3 ligase that mediated this process remains unclear. Materials and methods: The interaction between ARID1A and ß-TRCP was verified by co-immunoprecipitation (Co-IP) assay. The degron site of ARID1A protein was analyzed by bioinformatics assay. Short hairpin RNAs (shRNAs) were used to knockdown (KD) gene expression. Results: Here we show that DNA damage promotes ARID1A ubiquitination and subsequent destruction via the ubiquitin E3 ligase complex SCFß-TRCP. ß-TRCP recognizes ARID1A through a canonical degron site (DSGXXS) after its phosphorylation in response to DNA damage. Notably, genetic inactivation of the Ataxia Telangiectasia Mutated (ATM) kinase impaired DNA damage-induced ARID1A destruction. Conclusions: Our studies provide a novel molecular mechanism for the negative regulation of ARID1A by ß-TRCP and ATM in DNA damaged gastric cancer cells.

12.
Talanta ; 201: 413-418, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31122443

RESUMO

Covalent organic framework TpBD was grafted on stainless steel wire with polydopamine as a linker. The fabricated TpBD bonded stainless steel wire was used as the solid-phase microextraction fiber to extract sixteen polycyclic aromatic hydrocarbons (PAHs) for subsequent GC-MS/MS determination in grilled meat samples. The developed method gave the limits of detection (S/N = 3) from 0.02 (pyrene)-1.66 (naphthalene) ng L-1 and enhancement factors from 1069 (naphthalene)-10879 (benz(a)anthracene). The relative standard deviations (RSDs) for intra-day and inter-day study are in the range of 2.6%-8.5% and 4.5%-9.4%, respectively. The fiber-to-fiber RSDs for three parallel prepared fibers were 5.3%-10.0%. One TpBD bonded fiber can stand at least 200 cycles without significant loss of extraction efficiency. The developed method was successfully applied for the determination of trace PAHs in grilled meat samples with recoveries from 85.1% to 102.8%.


Assuntos
Contaminação de Alimentos/análise , Carne/análise , Estruturas Metalorgânicas/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Microextração em Fase Sólida/métodos , Aço Inoxidável/química , Animais , Galinhas , Cromatografia Gasosa-Espectrometria de Massas/métodos , Indóis/química , Limite de Detecção , Polímeros/química , Produtos Avícolas/análise , Carne Vermelha/análise , Ovinos , Microextração em Fase Sólida/instrumentação , Suínos , Espectrometria de Massas em Tandem/métodos
13.
Nat Commun ; 10(1): 1009, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30824705

RESUMO

This Article contains an error in Fig. 1, in which the structures of '(+)-Ac-L-Ta' and 'CTp' are drawn incorrectly. The correct version of Fig. 1 is shown below. The error has not been fixed in the original PDF and HTML versions of the Article.

14.
Chem Commun (Camb) ; 54(83): 11765-11768, 2018 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-30276397

RESUMO

A layer-by-layer approach was developed to prepare 3D covalent organic framework COF-300/silica composites (COF-300@SiO2) with uniform morphology as the stationary phase for high performance liquid chromatography separation of position isomers with high efficiency, selectivity and precision.

15.
World J Gastroenterol ; 24(23): 2501-2507, 2018 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-29930471

RESUMO

AIM: To determine the efficacy and safety of transarterial embolization and low-dose continuous hepatic arterial infusion chemotherapy with oxaliplatin and raltitrexed in hepatocellular carcinoma (HCC) with major portal vein tumor thrombus (MPVTT). METHODS: Eighty-six patients with MPVTT accepted routine embolization. The catheter was kept in the hepatic artery and oxaliplatin (50 mg in 250 mL of glucose) was infused by pump for 4 h, followed by raltitrexed (2 mg in 100 mL of 0.9% saline) infusion by pump for the next 1 h. The efficacy and safety were evaluated after the transarterial chemoembolization (TACE). RESULTS: Full or partial embolization was achieved in 86 cases, where all the cases received low dose continuous hepatic arterial infusion chemotherapy. Complete responses (CRs), partial responses (PRs), stable disease (SD), and disease progression (PD) for intrahepatic disease were observed in 0, 45, 20, and 21 patients, respectively. The 1-, 2-and 3-year overall survival rates of the 86 patients were 40.7%, 22.1%, and 8.1% respectively, and the median survival time was 8.7 mo. Complication was limited. CONCLUSION: TACE with low dose continuous hepatic arterial infusion of oxaliplatin and raltitrexed could be an option in MPVTT patient; it was shown to be effective in patients with advanced HCC with MPVTT with less toxicity.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Neoplasias Hepáticas/terapia , Trombose/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Cateteres , Quimioembolização Terapêutica/efeitos adversos , Quimioembolização Terapêutica/instrumentação , Feminino , Artéria Hepática , Humanos , Infusões Intra-Arteriais , Fígado/irrigação sanguínea , Fígado/patologia , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Compostos Organoplatínicos/administração & dosagem , Oxaliplatina , Veia Porta/patologia , Quinazolinas/administração & dosagem , Estudos Retrospectivos , Taxa de Sobrevida , Tiofenos/administração & dosagem , Trombose/complicações , Resultado do Tratamento
16.
J Chromatogr A ; 1542: 1-18, 2018 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-29496190

RESUMO

Covalent organic frameworks (COFs) are a new class of multifunctional crystalline organic polymer constructed with organic monomers via robust covalent bonds. The unique properties such as convenient modification, low densities, large specific surface areas, good stability and permanent porosity make COFs great potential in separation science. This review shows the state-of-the art for the application of COFs and their composites in analytical separation science. COFs and their composites have been explored as promising sorbents for solid phase extraction, potential coatings for solid phase microextraction, and novel stationary phases for gas chromatography, high-performance liquid chromatography and capillary electrochromatography. The prospects of COFs for separation science are also presented, which can offer an outlook and reference for further study on the applications of COFs.


Assuntos
Técnicas de Química Analítica/instrumentação , Técnicas de Química Analítica/tendências , Estruturas Metalorgânicas/química , Polímeros/química , Técnicas de Química Analítica/normas , Porosidade
17.
ACS Appl Mater Interfaces ; 9(29): 24999-25005, 2017 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-28657293

RESUMO

High crystallinity of covalent organic frameworks (COFs) with dual fluorescence emissions has not been reported so far. Here, we show the rational design and preparation of high-crystallinity COF TzDa via the synergetic interaction of docking sites and hydrogen bonds: 4,4',4″-(1,3,5-Triazine-2,4,6-triyl)trianiline (Tz) with the docking site and 2,5-dihydroxyterephthalaldehyde (Da) with the OH group are employed to synthesize the imine-linked two-dimensional high-crystallinity layered structure TzDa. The prepared mesoporous TzDa (ca. 36 Å) exhibits high thermal and chemical stability. The intramolecular charge transfer (ICT) and excited-state intramolecular proton transfer (ESIPT) effects bring TzDa two main fluorescence emissions around 500 and 590 nm. Water molecules can interfere with the ICT and ESIPT effects, allowing the development of a ratiometric fluorescent sensor for water in organic solvents. The proposed sensor shows high sensitivity to trace water in conventional organic solvents. The high stability of TzDa allows its recyclable uses for trace water detection. This work not only offers a platform for the construction of high-crystallinity COFs, but also provides a rational design of COFs with dual fluorescence emissions for ratiometric sensing applications.

18.
Nat Commun ; 7: 12104, 2016 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-27401541

RESUMO

Covalent organic frameworks (COFs) are a novel class of porous materials, and offer great potential for various applications. However, the applications of COFs in chiral separation and chiral catalysis are largely underexplored due to the very limited chiral COFs available and their challenging synthesis. Here we show a bottom-up strategy to construct chiral COFs and an in situ growth approach to fabricate chiral COF-bound capillary columns for chiral gas chromatography. We incorporate the chiral centres into one of the organic ligands for the synthesis of the chiral COFs. We subsequently in situ prepare the COF-bound capillary columns. The prepared chiral COFs and their bound capillary columns give high resolution for the separation of enantiomers with excellent repeatability and reproducibility. The proposed strategy provides a promising platform for the synthesis of chiral COFs and their chiral separation application.

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