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1.
J Virol ; 98(3): e0168623, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38376196

RESUMEN

The porcine reproductive and respiratory syndrome virus (PRRSV) can lead to severe reproductive problems in sows, pneumonia in weaned piglets, and increased mortality, significantly negatively impacting the economy. Post-translational changes are essential for the host-dependent replication and long-term infection of PRRSV. Uncertainty surrounds the function of the ubiquitin network in PRRSV infection. Here, we screened 10 deubiquitinating enzyme inhibitors and found that the ubiquitin-specific proteinase 1 (USP1) inhibitor ML323 significantly inhibited PRRSV replication in vitro. Importantly, we found that USP1 interacts with nonstructural protein 1ß (Nsp1ß) and deubiquitinates its K48 to increase protein stability, thereby improving PRRSV replication and viral titer. Among them, lysine at position 45 is essential for Nsp1ß protein stability. In addition, deficiency of USP1 significantly reduced viral replication. Moreover, ML323 loses antagonism to PRRSV rSD16-K45R. This study reveals the mechanism by which PRRSV recruits the host factor USP1 to promote viral replication, providing a new target for PRRSV defense.IMPORTANCEDeubiquitinating enzymes are critical factors in regulating host innate immunity. The porcine reproductive and respiratory syndrome virus (PRRSV) nonstructural protein 1ß (Nsp1ß) is essential for producing viral subgenomic mRNA and controlling the host immune system. The host inhibits PRRSV proliferation by ubiquitinating Nsp1ß, and conversely, PRRSV recruits the host protein ubiquitin-specific proteinase 1 (USP1) to remove this restriction. Our results demonstrate the binding of USP1 to Nsp1ß, revealing a balance of antagonism between PRRSV and the host. Our research identifies a brand-new PRRSV escape mechanism from the immune response.


Asunto(s)
Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Animales , Femenino , Endopeptidasas/genética , Péptido Hidrolasas/metabolismo , Síndrome Respiratorio y de la Reproducción Porcina/metabolismo , Síndrome Respiratorio y de la Reproducción Porcina/virología , Virus del Síndrome Respiratorio y Reproductivo Porcino/metabolismo , Porcinos , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/metabolismo , Replicación Viral
2.
J Virol ; 97(12): e0157423, 2023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-38014947

RESUMEN

IMPORTANCE: Marek's disease virus (MDV) is a highly infectious and oncogenic virus that can induce severe T cell lymphomas in chickens. MDV encodes more than 100 genes, most of which have unknown functions. This work indicated that the LORF9 gene is necessary for MDV early cytolytic replication in B lymphocytes. In addition, we have found that the LORF9 deletion mutant has a comparative immunological protective effect with CVI988/Rispens vaccine strain against very virulent MDV challenge. This is a significant discovery that LORF9 can be exploited as a possible target for the development of an MDV gene deletion vaccine.


Asunto(s)
Herpesvirus Gallináceo 2 , Vacunas contra la Enfermedad de Marek , Enfermedad de Marek , Enfermedades de las Aves de Corral , Animales , Linfocitos B , Pollos , Eliminación de Gen , Herpesvirus Gallináceo 2/genética , Enfermedad de Marek/prevención & control , Enfermedad de Marek/genética , Vacunas contra la Enfermedad de Marek/genética , Replicación Viral
3.
J Med Virol ; 95(1): e28324, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36401345

RESUMEN

Dynamic alteration of the epitranscriptome exerts regulatory effects on the lifecycle of oncogenic viruses in vitro. However, little is known about these effects in vivo because of the general lack of suitable animal infection models of these viruses. Using a model of rapid-onset Marek's disease lymphoma in chickens, we investigated changes in viral and host messenger RNA (mRNA) N6-methyladenosine (m6 A) modification during Marek's disease virus (MDV) infection in vivo. We found that the expression of major epitranscriptomic proteins varies among viral infection phases, reprogramming both the viral and the host epitranscriptomes. Specifically, the methyltransferase-like 3 (METTL3)/14 complex was suppressed during the lytic and reactivation phases of the MDV lifecycle, whereas its expression was increased during the latent phase and in MDV-induced tumors. METTL3/14 overexpression inhibits, whereas METTL3/14 knockdown enhances, MDV gene expression and replication. These findings reveal the dynamic features of the mRNA m6 A modification program during viral replication in vivo, especially in relation to key pathways involved in tumorigenesis.


Asunto(s)
Enfermedad de Marek , Animales , Enfermedad de Marek/genética , Virus Oncogénicos/genética , Pollos , ARN Mensajero/genética , ARN Mensajero/metabolismo
4.
Anal Bioanal Chem ; 412(23): 5653-5661, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32621093

RESUMEN

A novel molecularly imprinted fluorescent sensor for the determination of 4-nitroaniline (4-NA) was synthesized via free radical polymerization with 3-[(7-methoxy-2-oxo-2H-chromen-4-yl)methyl]-1-vinyl-1H-imidazol-3-ium bromide as the fluorescence functional monomer, 4-NA as the template molecule, ethylene glycol dimethacrylate as the cross-linker, and 2,2'-azo(bisisobutyronitrile) as the initiator. The obtained fluorescent poly(ionic liquid) was characterized through Fourier transform infrared, scanning electron microscopy, Brunauer-Emmett-Teller analysis, and fluorescence spectrophotometry. The fluorescent sensor had high fluorescence intensity, short detection time (0.5 min), good selectivity, and excellent sensitivity (limit of detection = 0.8 nM) for 4-NA, with good linear relationships of 2.67-10,000 nM. The practical applicability of the fluorescence sensor in detecting 4-NA in industrial wastewater and spiked environmental water was demonstrated, and a satisfactory result was obtained. Graphical abstract Highly sensitive and selective detection of 4-nitroaniline in water by a novel fluorescent sensor based on molecularly imprinted poly(ionic liquid).

5.
Mikrochim Acta ; 186(5): 287, 2019 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-30989406

RESUMEN

The authors describe a fluorometric assay for cardiac myoglobin (Mb), a marker for myocardial infarction. An Mb-binding aptamer was labeled with pyrene and adsorbed on the surface of graphene oxide (GO) via noncovalent and reversible binding forces. This causes the fluorescence of pyrene (best measured at excitation/emission wavelengths of 275/376 nm) to be quenched. However, fluorescence is restored on addition of pyrene due to the strong affinity between Mb and aptamer which causes its separation from GO. Fluorescence increases linearly in the 5.6-450 pM Mb concentration range, and the lower detection limit is 3.9 pM (S/N = 3). The assay was applied to the determination of cardiac Mb in spiked serum, and satisfactory results were obtained. Graphical abstract Schematic presentation of the detection of Mb (cardiac myoglobin) by using a fluorometric method based on pyrene-modified anti-Mb aptamer and GO (graphene oxide) through fluorescence quenching and subsequent recovery.


Asunto(s)
Aptámeros de Nucleótidos/metabolismo , Técnicas Biosensibles/métodos , Grafito/química , Miocardio/metabolismo , Mioglobina/análisis , Pirenos/química , Transferencia de Energía , Fluorometría , Humanos , Límite de Detección , Mioglobina/metabolismo
6.
Anal Bioanal Chem ; 410(18): 4285-4291, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29725733

RESUMEN

Acute myocardial infarction (AMI) is one of the leading risks to global health. Thus, the rapid, accurate early diagnosis of AMI is highly critical. Human cardiac troponin I (cTnI) has been regarded as a golden biomarker for AMI due to its excellent selectivity. In this work, a novel fluorescent aptasensor based on a graphene oxide (GO) platform was developed for the highly sensitive and selective detection of cTnI. GO binds to the fluorescent anti-cTnI aptamer and quenches its fluorescence. In the presence of cTnI, the fluorescent anti-cTnI aptamer leaves the surface of GO, combines with cTnI because of the powerful affinity of the fluorescent anti-cTnI aptamer and cTnI, and then restores the fluorescence of the fluorescent anti-cTnI aptamer. Fluorescence-enhanced detection is highly sensitive and selective to cTnI. The method exhibited good analytical performance with a reasonable dynamic linearity at the concentration range of 0.10-6.0 ng/mL and a low detection limit of 0.07 ng/mL (S/N = 3). The fluorescent aptasensor also exhibited high selectivity toward cTnI compared with other interference proteins. The proposed method may be a potentially useful tool for cTnI determination in human serum. Graphical abstract A novel fluorescent aptasensor for the highly sensitive and selective detection of cardiac troponin I based on a graphene oxide platform.


Asunto(s)
Aptámeros de Nucleótidos/metabolismo , Biomarcadores/sangre , Colorantes Fluorescentes/química , Grafito/química , Infarto del Miocardio/diagnóstico , Troponina I/sangre , Técnicas Biosensibles/métodos , Diagnóstico Precoz , Transferencia Resonante de Energía de Fluorescencia , Humanos , Límite de Detección , Infarto del Miocardio/sangre , Óxidos/química , Sensibilidad y Especificidad
7.
Chem Commun (Camb) ; 60(3): 324-327, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38063134

RESUMEN

Separator modification has become one of the most facile and promising methods to inhibit Li dendrite formation. Herein, an open-pore MFI zeolite nanosheet-modified polyacrylonitrile (open-pore MFI NSs@PAN) separator was prepared via the combination of vacuum filtration and the electrospinning technique. The straight channels in the MFI NSs, the fluid channels formed by the stacking of the MFI NSs and the interconnected network channels formed by the interweaving of the PAN nanofibers jointly constructed a micro/nano pore structure, which provides sufficient Li+ transport channels and enables uniform Li+ flux. Consequently, the open-pore MFI NSs@PAN separator-based cell delivers a stable and uniform Li deposition, demonstrating a more stable cycle-life and better rate capability. Redistributing Li+ flux through straight channel zeolite nanosheets provides a powerful method for suppressing Li dendrites, presenting enormous potential for promoting the commercial application of lithium metal batteries.

8.
Anal Bioanal Chem ; 405(29): 9563-70, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24126836

RESUMEN

Novel imidazole fluorescent ionic liquids with anthracene groups (ImS-FILA) were synthesized for the first time to act as fluorescent probes. They were developed for the determination of superoxide anion radicals (O2 (•-)) in an aqueous system. O2 (•-) was produced by pyrogallol autoxidation. The fluorescence of ImS-FILA was quenched by superoxide anion radicals. The π-bond structure of the fluorescent molecules was oxidized and damaged. This method is very simple and sensitive. The linear range of sensitivity was 1-70 µM ImS-FILA, and the detection limit for reactive oxygen species was 0.1 µM. This method was used to detect superoxide radicals in papaya and garlic, with satisfactory results. Further work is needed to demonstrate the utility of this method in detecting reactive oxygen species in a biological aqueous system.


Asunto(s)
Carica/química , Ajo/química , Imidazoles/química , Espectrometría de Fluorescencia/métodos , Superóxidos/química , Aniones/química , Fluorescencia , Líquidos Iónicos/química
9.
RSC Adv ; 13(26): 17622-17627, 2023 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-37312986

RESUMEN

Ultraviolet (UV) radiation is extremely dangerous to humans and can contribute to immunosuppression, erythema, early ageing and skin cancer. UV protection finishing may greatly influence the handling and permeability of fabrics, while UV-proof fibres can guarantee close contact between UV-resistant agents and fabric without affecting the handling of the fabric. In this study, polyacrylonitrile (PAN)/UV absorber 329 (UV329)/titanium dioxide (TiO2) composite nanofibrous membranes with complex, highly efficient UV resistance were fabricated via electrospinning. UV329 was included in the composite to further strengthen the UV resistance properties via absorption function, while TiO2 inorganic nanoparticles were added to provide UV shielding function. The presence of UV329 and TiO2 in the membranes was confirmed using Fourier-transform infrared spectroscopy, which also showed the absence of chemical bonds between PAN and the anti-UV agents. The PAN/UV329/TiO2 membranes exhibited a UV protection factor of 1352 and a UVA transmittance of 0.6%, which indicate their extraordinary UV resistance properties. Additionally, filtration performance was investigated in order to expand the application field of the UV-resistant PAN/UV329/TiO2 membranes, and the composite nanofibrous membranes showed a UV filtration efficiency of 99.57% and a pressure drop of 145 Pa. The proposed multi-functional nanofibrous membranes have broad application prospects in outdoor protective clothing and window air filters.

10.
Anal Chim Acta ; 1278: 341692, 2023 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-37709445

RESUMEN

BACKGROUND: Liver cancer is one of the most common cancers in the world, and it seriously threatens human life and health. Alpha-fetoprotein (AFP), as a carcinogenic glycoprotein, is an important serum marker for detecting liver cancer. Therefore, the accurate and sensitive determination of AFP is crucial for the early diagnosis and treatment of liver cancer. To this end, a label-free fluorescence aptasensor for detecting AFP based on the use of a novel organic Compound D with an aggregation-induced emission activity and aptamer-modified magnetic microparticles was constructed. RESULTS: Compound D could combine with the complementary short chain of the aptamer (CSC-Apt) of AFP to form the D/CSC-Apt complex and realize the fluorescence enhancement of Compound D. Then, magnetic particles modified by the Apt of AFP (Apt-Fe3O4) were prepared. When AFP (or nontarget substance) and D/CSC-Apt were successively added to the Apt-Fe3O4 solution, Apt-Fe3O4 selectively bound to AFP or the D/CSC-Apt complex. Magnetic separation technology showed the changes in the fluorescence intensity of the supernatant. The research results revealed a good linear relationship between the changes in the fluorescence intensity of the supernatant and concentration of AFP within the concentration range of 10-10000 pg mL-1. The proposed aptasensor could achieve high-sensitivity and high-specificity detection of AFP, and its limit of detection was 3 pg mL-1 (S/N = 3). SIGNIFICANCE AND NOVELTY: The sensor combines the advantages of high selectivity of Apt, high sensitivity of fluorescence analysis, AIE effect and good water solubility of Compound D, and rapid separation using magnetic separation technology. And it can be directly used for the detection of AFP in actual serum samples with high accuracy, whereas most of the methods reported in the literature can only detect AFP in spiked serum samples.


Asunto(s)
Neoplasias Hepáticas , alfa-Fetoproteínas , Humanos , Carcinógenos , Fluorometría , Neoplasias Hepáticas/diagnóstico , Oligonucleótidos , Compuestos Orgánicos
11.
Polymers (Basel) ; 14(23)2022 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-36501689

RESUMEN

Waterproof breathable functional membranes have broad application prospects in the field of outdoors textiles. The fluorine-containing microporous membranes of the mainstream functional products easily cause harm to the environment, and thus, the fluorine-free environmental nanofibrous membranes are an important development direction for functional membranes. In this subject, the electrospun polyacrylonitrile nanofibrous membranes were first hydrophobically modified by amino functional modified polysiloxane (AMP), followed by in situ cross-linking modified with 4, 4'-methyl diphenylene diisocyanate (MDI). The fluorine-free modification by AMP altered the surface of the membranes from hydrophilic to hydrophobic, and greatly improved the waterproof properties with the hydrostatic pressure reaching to 87.6 kPa. In addition, the formation of bonding points and the in situ preparation of polyuria through the reaction between the isocyanate in MDI and the amino group in AMP, could improve the mechanical properties effectively. When using AMP with the concentration of 1 wt% and MDI with the concentration of 2 wt%, the relatively good comprehensive performance was obtained with good water resistance (93.8 kPa), modest vapor permeability (4.7 kg m-2 d-1) and air permeability (12.7 mm/s). Based on these testing data, the modified nanofibrous membranes had excellent waterproof and breathable properties, which has future potential in outdoor sports apparel.

12.
Anal Methods ; 14(44): 4576-4582, 2022 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-36341556

RESUMEN

Highly sensitive and specific detection of cancer markers (such as carcinoembryonic antigen) is very important for early diagnosis and treatment of cancer. Herein, we developed a label-free fluorescent aptamer biosensor based on the aggregation-induced emission (AIE) effect and hydroxycobalt oxide (CoOOH) platform, and used it to detect carcinoembryonic antigen (CEA) with high sensitivity and specificity. Fluorescent ionic liquid Compound B can combine with a CEA aptamer (CEA-Apt) through electrostatic attraction and hydrophobic interaction to form an ionic liquid/aptamer (CEA-Apt/B) complex and produce the AIE effect, thereby enhancing the fluorescence intensity of B. CEA-Apt/B was adsorbed on the surface of CoOOH when CoOOH was added to the buffer solution, and the fluorescence of B was quenched. After adding CEA to the solution, CEA-Apt/B bound to CEA and separated from the surface of CoOOH because CEA-Apt had stronger affinity for CEA, resulting in fluorescence recovery of B. In the level range of 0.67-10000 pg mL-1, the fluorescence recovery intensity of the sensor had an excellent linear relationship with the level of CEA, and its LOD was 0.2 pg mL-1 (S/N = 3). In addition, the sensor had good selectivity and can be directly used to detect CEA in human serum with high accuracy.


Asunto(s)
Aptámeros de Nucleótidos , Líquidos Iónicos , Humanos , Antígeno Carcinoembrionario/química , Aptámeros de Nucleótidos/química , Óxidos/química
13.
Anal Chim Acta ; 1122: 9-19, 2020 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-32503748

RESUMEN

Two-dimensional metal-organic framework (MOF) has the advantages of high mass transfer speed, tunable porosity, and strong electron transfer capability. The different metal center can give MOF with good electrochemical activity because of the mulriple valence state. Here, a simple and economical method was used to successfully prepare a different metal-coordinated two-dimensional (2D) MOF with electrochemical exfoliated graphene (EG) at room temperature. As the electrode material for the nonenzymatic glucose sensor, the modified MOF/EG electrode had high electrocatalytic activity for glucose sensing. Thereinto, the nonenzymatic Co-MOF/EG sensor had nice detection performance with wide linear range (1.0-3330 µM) and minimum detection limit (0.58 µM, S/N = 3). The detection response in alkaline solution was less than 0.9 s. Most importantly, the stability and conductivity of the Co-MOF/EG were much higher than Ni-MOF/EG and NiCo-MOF/EG. The oxidation potential of Co-MOF/EG for glucose was the lowest, and the detection performance was the best at low oxidation potential of 0.2 V. The coordination unsaturated metal ion was the main active center of glucose electrocatalysis. We believe that the illustrated MOF/EG was an effective strategy for creating an active multi-phase catalyst with atomic precision.


Asunto(s)
Técnicas Biosensibles , Técnicas Electroquímicas , Glucosa/análisis , Grafito/química , Estructuras Metalorgánicas/química , Humanos , Oxidación-Reducción , Tamaño de la Partícula , Propiedades de Superficie
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 228: 117714, 2020 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-31718976

RESUMEN

A novel fluorescent biosensor based on dabcyl [(E)-4-((4-(dimethylamino) phenyl) diazenyl)benzoic acid] -modified anti-Mb aptamer (D-AMA) and 6-FAM(6-carboxyfluorescein) -modified complementary short chain (F-CSC)for the specific and sensitive detection of Mb levels is presented in this study. In PBS buffer solution, D-AMA bound to F-CSC, and then dabcyl quenched the fluorescence of 6-FAM. After adding Mb into the system, D-AMA bound to Mb and separated from F-CSC. The fluorescence of 6-FAM was restored after it separated from dabcyl. The assay exhibited high specificity and sensitivity toward Mb, with a low limit of detection of 0.07 ng/mL (S/N = 3) and linear relationships of 0.1-5 ng/mL. It was further applied to detect Mb levels in spiked human blood sera samples.


Asunto(s)
Aptámeros de Nucleótidos/química , Técnicas Biosensibles , Fluoresceínas/química , Mioglobina/sangre , Animales , Secuencia de Bases , Bovinos , ADN/análisis , Humanos , Espectrometría de Fluorescencia
15.
Front Immunol ; 11: 575818, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33072119

RESUMEN

Pigs have anatomical and physiological characteristics comparable to those in humans and, therefore, are a favorable model for immune function research. Interferons (IFNs) and inflammasomes have essential roles in the innate immune system. Here, we report that G10, a human-specific agonist of stimulator of interferon genes (STING), activates both type I IFN and the canonical NLRP3 inflammasome in a STING-dependent manner in porcine cells. Without a priming signal, G10 alone transcriptionally stimulated Sp1-dependent p65 expression, thus triggering activation of the nuclear factor-κB (NF-κB) signaling pathway and thereby priming inflammasome activation. G10 was also found to induce potassium efflux- and NLRP3/ASC/Caspase-1-dependent secretion of IL-1ß and IL-18. Pharmacological and genetic inhibition of NLRP3 inflammasomes increased G10-induced type I IFN expression, thereby preventing virus infection, suggesting negative regulation of the NLRP3 inflammasome in the IFN response in the context of STING-mediated innate immune activation. Overall, our findings reveal a new mechanism through which G10 activates the NLRP3 inflammasome in porcine cells and provide new insights into STING-mediated innate immunity in pigs compared with humans.


Asunto(s)
Inmunidad Innata/efectos de los fármacos , Inflamasomas/agonistas , Interferón Tipo I/metabolismo , Proteínas de la Membrana/agonistas , Proteína con Dominio Pirina 3 de la Familia NLR/agonistas , Tiazinas/farmacología , Animales , Proteínas Adaptadoras de Señalización CARD/metabolismo , Caspasa 1/metabolismo , Chlorocebus aethiops , Células HEK293 , Humanos , Inflamasomas/genética , Inflamasomas/inmunología , Inflamasomas/metabolismo , Interferón Tipo I/genética , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/inmunología , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Transducción de Señal , Factor de Transcripción Sp1/genética , Factor de Transcripción Sp1/metabolismo , Sus scrofa , Células THP-1 , Factor de Transcripción ReIA/genética , Factor de Transcripción ReIA/metabolismo , Células Vero
16.
Materials (Basel) ; 12(2)2019 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-30650568

RESUMEN

In this work, a series of two-dimensional (2D) large-size nanosheets were prepared through one-step exfoliation of the huge K4Nb6O17 crystals. The K4Nb6O17 nanosheets with the thickness of about 2 nm was used as the templates of dopamine polymerization and was then carbonized to form C-doped K4Nb6O17 nanosheets. More importantly, the C-doped K4Nb6O17 nanosheets exhibited excellent electrochemical performance with high specific capacity (381 mA h g-1 at 0.05 A g-1, 0.5⁻3.0 V vs. Li/Li⁺) and stable cyclability at high current density (remarkably, preserved a capacity of discharge approximately 90 mA h g-1 at 5 A g-1 after 1000 cycles). The good electrochemical performances of the C-doped K4Nb6O17 nanosheets can be attributed to the outstanding 2D structure and large specific surface, which afforded the short transport route for ion and electron. These noteworthy results demonstrated that the new 2D nanomaterials might be potential candidates for the high-performance, environmentally friendly, and low-cost electrochemical energy storage equipment.

17.
Chem Sci ; 10(19): 5025-5030, 2019 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-31183052

RESUMEN

The rational modulation of receptor affinity through distal-site mutation and allosteric control is valuable in biosensor designing to tune the useful dynamic range. Our ability to programmatically engineer dual-affinity regulation into diverse affinities of target binding and activities of hybridization chain reaction, however, remains limited. By programmable engineering of the switching equilibria of the recognition hairpin using distal-site mutation inhibition and allosteric activation, we obtained a set of receptors varying significantly in affinities of target binding and activities of the hybridization chain reaction. For the first time, we developed an electrocatalytic biosensor for nucleic acid detection with a tunable dynamic range based on a conformational switch triggered bidirectional hybridization chain reaction and blocker assisted multivalent binding. This designable biosensor thus enables single-step incubation, diverse affinities of target binding, diverse efficiencies of signal amplification and diverse single nucleotide discrimination for quantitative analyses of nucleic acids of various lengths in serum, which holds great potential as a compelling platform suitable for liquid biopsy.

18.
Biosens Bioelectron ; 108: 38-45, 2018 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-29499557

RESUMEN

Molecularly imprinted polymers prepared using traditional functional monomers and cross-linkers exhibit slow binding kinetics, low electrocatalytic activity and adsorption capacity. Herein, we report a new composite of ionic liquid-based graphene and molecularly imprinted polymer (IL-GR-MIP) with high electrocatalytic activity and adsorption capacity to construct an effective electrochemical sensor for 6-benzylaminopurine (6-BAP). Our objective was to enhance the efficiency of the sensor by incorporating more IL in the MIP framework. We synthesized IL-GR-MIP using ionic liquid 1-vinyl-3-butylimidazolium tetrafluoroborate (IL1) as functional monomer, ionic liquid 1,4-butanediyl-3,3'-bis-l-vinylimidazolium dibromide (IL2) as cross-linker, 6-BAP as template, and GR as supporter. IL-GR-MIP was characterized by Fourier transform infrared spectroscopy, thermal gravimetric analysis, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscope. Compared with GR-MIP composites based on methacrylic acid or IL1 as functional monomer, N, N'-methylenebisacrylamide and ethylene glycol dimethacrylate as cross-linker, the IL-GR-MIP (prepared with ionic liquids as functional monomer and cross-linker) sensor exhibited highest peak current for 6-BAP. The results indicate the ability of IL2 as cross-linker to enhance electrocatalytic activity and adsorption capacity for 6-BAP of IL-GR-MIP. Under the optimized conditions, the peak current of IL-GR-MIP sensor was linear to 6-BAP concentration in the range of 0.5-50 µM with a detection limit of 0.2 µM (S/N = 3). The IL-GR-MIP sensor exhibited good selectivity with the anti-interference ability of 1000-fold ascorbic acid in 6-BAP determination. Furthermore, we demonstrated practical applicability of IL-GR-MIP sensor in detecting 6-BAP in real samples with satisfactory results.


Asunto(s)
Compuestos de Bencilo/análisis , Técnicas Biosensibles/métodos , Citocininas/análisis , Técnicas Electroquímicas/métodos , Impresión Molecular/métodos , Reguladores del Crecimiento de las Plantas/análisis , Polímeros/química , Purinas/análisis , Acrilamidas/química , Adsorción , Compuestos de Bencilo/química , Catálisis , Citocininas/química , Grafito/química , Imidazoles/química , Líquidos Iónicos/química , Límite de Detección , Metacrilatos/química , Reguladores del Crecimiento de las Plantas/química , Polímeros/síntesis química , Purinas/química
19.
Biosens Bioelectron ; 100: 565-570, 2018 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-29024921

RESUMEN

Polydopamine (PDA) can be formed by monomeric self-polymerization in water. This convenient behavior was exploited to prepare a molecularly imprinted polymer (MIP) layer on the surface of multi-walled carbon nanotubes (MWCNTs) with sunset yellow (SY) as a template molecule. The prepared nanocomposites were characterized, and their electrochemical behavior towards SY was investigated. Under the optimized conditions, a glassy carbon electrode modified with the imprinted nanocomposite showed a highly selective and ultrasensitive electrochemical response to SY compared with the performance of control electrodes and previously reported electrochemical sensors for SY. The improved behavior of the developed sensor can be attributed to its superficial highly matched imprinted cavities on the excellent electrocatalytic matrix of MWCNTs and the electronic barrier of the non-imprinted PDA to outside molecules. The fabricated sensor expressed a linear relationship to SY concentrations from 2.2nM to 4.64µM with a detection limit of 1.4nM (S/N = 3). The sensor also exhibited excellent selectivity for SY over its structural analogs, good stability, and adequate reproducibility. The prepared sensor was successfully used to detect SY in real spiked samples. This methodology has potential application value and may be readily adapted to design other PDA-based MIP sensors.


Asunto(s)
Compuestos Azo/análisis , Colorantes/análisis , Técnicas Electroquímicas/métodos , Indoles/química , Impresión Molecular/métodos , Nanotubos de Carbono/química , Polímeros/química , Análisis de los Alimentos/métodos , Límite de Detección , Reproducibilidad de los Resultados
20.
Anal Sci ; 31(8): 793-8, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26256603

RESUMEN

In this study, electrochemical molecularly imprinted sensors were fabricated and used for the determination of ascorbic acid (AA). Nanofiber membranes of cellulose acetate (CA)/multi-walled carbon nanotubes (MWCNTs)/polyvinylpyrrolidone (PVP) (CA/MWCNTs/PVP) were prepared by electrospinning technique. After being transferred to a glass carbon electrode (GC), the nanofiber interface was further polymerized with pyrrole through electrochemical cyclic voltammetry (CV) technique. Meanwhile, target molecules (such as AA) were embedded into the polypyrrole through the hydrogen bond. The effects of monomer concentration (pyrrole), the number of scan cycles and scan rates of polymerization were optimized. Differential pulse voltammetry (DPV) tests indicated that the oxidation current of AA (the selected target) were higher than that of the structural analogues, which illustrated the selective recognition of AA by molecularly imprinted sensors. Simultaneously, the molecularly imprinted sensors had larger oxidation current of AA than non-imprinted sensors in the processes of rebinding. The electrochemical measurements showed that the molecularly imprinted sensors demonstrated good identification behavior for the detection of AA with a linear range of 10.0 - 1000 µM, a low detection limit down to 3 µM (S/N = 3), and a recovery rate range from 94.0 to 108.8%. Therefore, the electrochemical molecularly imprinted sensors can be used for the recognition and detection of AA without any time-consuming elution. The method presented here demonstrates the great potential for electrospun nanofibers and MWCNTs to construct electrochemical sensors.


Asunto(s)
Ácido Ascórbico/análisis , Electricidad , Electroquímica/instrumentación , Impresión Molecular , Nanofibras/química , Adsorción , Ácido Ascórbico/química , Celulosa/análogos & derivados , Celulosa/química , Límite de Detección , Nanotubos de Carbono/química , Povidona/química , Factores de Tiempo
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