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1.
Anal Chem ; 96(11): 4479-4486, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38454359

RESUMO

Metal-organic gels (MOGs) are a new type of intelligent soft material, which are bridged by metal ions and organic ligands through noncovalent interactions. In this paper, we prepared highly stable P-MOGs, using the classical organic electrochemiluminescence (ECL) luminescence meso-tetra(4-carboxyphenyl)porphine as the organic ligand and Fe3+ as the metal ion. Surprisingly, P-MOGs can stably output ECL signals at a low potential. We introduced P-MOGs into the ECL resonance energy transfer strategy (ECL-RET) and constructed a quenched ECL immunosensor for the detection of the SARS-CoV-2 nucleocapsid protein (SARS-CoV-2-N). In the ECL-RET system, P-MOGs were used as energy donors, and Au@Cu2O@Fe3O4 were selected as energy acceptors. The ultraviolet-visible spectrum of Au@Cu2O@Fe3O4 partially overlaps with the ECL spectrum of P-MOGs, which can effectively touch off the ECL-RET behavior between the donors and receptors. Under the ideal experimental situation, the linear detection range of the SARS-CoV-2-N concentration was 10 fg/mL to 100 ng/mL, and the limit of detection was 1.5 fg/mL. This work has broad application prospects for porphyrin-MOGs in ECL sensing.


Assuntos
Técnicas Biossensoriais , COVID-19 , Nanopartículas Metálicas , Humanos , Medições Luminescentes , SARS-CoV-2 , Técnicas Eletroquímicas , Limite de Detecção , Imunoensaio , COVID-19/diagnóstico , Géis , Proteínas do Nucleocapsídeo
2.
Anal Chem ; 96(21): 8390-8398, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38716680

RESUMO

In this work, a microfluidic immunosensor chip was developed by incorporating microfluidic technology with electrochemiluminescence (ECL) for sensitive detection of human epidermal growth factor receptor-2 (HER2). The immunosensor chip can achieve robust reproducibility in mass production by integrating multiple detection units in a series. Notably, nanoscale materials can be better adapted to microfluidic systems, greatly enhancing the accuracy of the immunosensor chip. Ag@Au NCs closed by glutathione (GSH) were introduced in the ECL microfluidic immunosensor system with excellent and stable ECL performance. The synthesized CeO2-Au was applied as a coreaction promoter in the ECL signal amplification system, which made the result of HER2 detection more reliable. In addition, the designed microfluidic immunosensor chip integrated the biosensing system into a microchip, realizing rapid and accurate detection of HER2 by its high throughput and low usage. The developed short peptide ligand NARKFKG (NRK) achieved an effective connection between the antibody and nanocarrier for improving the detection efficiency of the sensor. The immunosensor chip had better storage stability and sensitivity than traditional detection methods, with a wide detection range from 10 fg·mL-1 to 100 ng·mL-1 and a low detection limit (LOD) of 3.29 fg·mL-1. In general, a microfluidic immunosensor platform was successfully constructed, providing a new idea for breast cancer (BC) clinical detection.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Eletrodos , Ouro , Medições Luminescentes , Nanopartículas Metálicas , Receptor ErbB-2 , Prata , Humanos , Receptor ErbB-2/análise , Receptor ErbB-2/imunologia , Nanopartículas Metálicas/química , Técnicas Eletroquímicas/métodos , Prata/química , Técnicas Biossensoriais/métodos , Ouro/química , Imunoensaio/métodos , Técnicas Analíticas Microfluídicas/instrumentação , Limite de Detecção , Cério/química
3.
Anal Chem ; 96(12): 4969-4977, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38486396

RESUMO

Metal nanoclusters (Me NCs) have become a research hotspot in the field of electrochemiluminescence (ECL) sensing analysis. This is primarily attributed to their excellent luminescent properties and biocompatibility along with their easy synthesis and labeling characteristics. At present, the application of Me NCs in ECL mainly focuses on precious metals, whose high cost, to some extent, limits their widespread application. In this work, Cu NCs with cathode ECL emissions in persulfate (S2O82-) were prepared as signal probes using glutathione as ligands, which exhibited stable luminescence signals and high ECL efficiency. At the same time, CaMnO3 was introduced as a co-reaction promoter to increase the ECL responses of Cu NCs, thereby further expanding their application potential in biochemical analysis. Specifically, the reversible conversion of Mn3+/Mn4+ greatly promoted the generation of sulfate radicals (SO4•-), providing a guarantee for improving the luminescence signals of Cu NCs. Furthermore, a short peptide (NARKFYKGC) was introduced to enable the fixation of antibodies to specific targets, preventing the occupancy of antigen-binding sites (Fab fragments). Therefore, the sensitivity of the biosensor could be significantly enhanced by releasing additional Fab fragments. Considering the approaches discussed above, the constructed biosensor could achieve sensitive detection of CD44 over a broad range (10 fg/mL-100 ng/mL), with an ultralow detection limit of 3.55 fg/mL (S/N = 3), which had valuable implications for the application of nonprecious Me NCs in biosensing analysis.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Cobre/química , Medições Luminescentes , Luminescência , Fragmentos Fab das Imunoglobulinas , Técnicas Eletroquímicas , Limite de Detecção , Nanopartículas Metálicas/química
4.
Anal Chem ; 96(4): 1678-1685, 2024 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-38215346

RESUMO

In this paper, an electrochemiluminescence (ECL) immunosensor for ultrasensitive detection of CA19-9 was constructed using ternary compound CdSSe nanoparticles as ECL emitter. The immunosensor employs Cu2S and gold-doped diindium trioxide (Au-In2O3) nanocubes as coreaction accelerators to achieve a double-amplification strategy. In general, a hexagonal maple leaf-shaped Cu2S with a large surface area was selected as the template, and the in situ growth of CdSSe on its surface was achieved using a hydrothermal method. The presence of Cu2S not only inhibited the aggregation of CdSSe nanoparticles to reduce their surface energy but also acted as an ECL cathode coreaction promoter, facilitating the generation of SO4•-. Consequently, the ECL intensity of CdSSe was significantly enhanced, and the reduction potential was significantly lower. In addition, the template method was employed to synthesize Au-In2O3 nanocubes, which offers the advantage of directly connecting materials with antibodies, resulting in a more stable construction of the immunosensor. Furthermore, In2O3 serves as a coreaction promoter, enabling the amplification strategy for ECL intensity of CdSSe, thus contributing to the enhanced sensitivity and performance of the immunosensor. The constructed immunosensor exhibited a wide linear range (100 µU mL-1 to 100 U mL-1) and a low detection limit of 80 µU mL-1, demonstrating its high potential and practical value for sensitive detection of CA19-9.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Antígeno CA-19-9 , Imunoensaio/métodos , Técnicas Biossensoriais/métodos , Testes Imunológicos , Semicondutores , Medições Luminescentes/métodos , Técnicas Eletroquímicas/métodos , Limite de Detecção , Ouro
5.
Anal Chem ; 96(10): 4067-4075, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38419337

RESUMO

In this work, an electrochemiluminescence (ECL) quenching system using multimetal-organic frameworks (MMOFs) was proposed for the sensitive and specific detection of heart-type fatty acid-binding protein (H-FABP), a marker of acute myocardial infarction (AMI). Bimetallic MOFs containing Ru and Mn as metal centers were synthesized via a one-step hydrothermal method, yielding RuMn MOFs as the ECL emitter. The RuMn MOFs not only possessed the strong ECL performance of Ru(bpy)32+ but also maintained high porosity and original metal active sites characteristic of MOFs. Moreover, under the synergistic effect of MOFs and Ru(bpy)32+, RuMn MOFs have more efficient and stable ECL emission. The trimetal-based MOF (FePtRh MOF) was used as the ECL quencher because of the electron transfer between FePtRh MOFs and RuMn MOFs. In addition, active intramolecular electron transfer from Pt to Fe or Rh atoms also occurred in FePtRh MOFs, which could promote intermolecular electron transfer and improve electron transfer efficiency to enhance the quenching efficiency. The proposed ECL immunosensor demonstrated a wide dynamic range and a low detection limit of 0.01-100 ng mL-1 and 6.8 pg mL-1, respectively, under optimal conditions. The ECL quenching system also presented good specificity, stability, and reproducibility. Therefore, an alternative method for H-FABP detection in clinical diagnosis was provided by this study, highlighting the potential of MMOFs in advancing ECL technology.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Imunoensaio/métodos , Técnicas Biossensoriais/métodos , Reprodutibilidade dos Testes , Proteína 3 Ligante de Ácido Graxo , Medições Luminescentes/métodos , Metais , Técnicas Eletroquímicas/métodos , Limite de Detecção , Nanopartículas Metálicas/química
6.
Mikrochim Acta ; 191(2): 89, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38206415

RESUMO

The interaction between the sensitive interfaces of photoelectrochemical (PEC) semiconductor nanomaterials and microscopic matter creates endless potential for the efficient detection of endocrine disruptor. This work presents the development of a high-efficiency PEC aptasensor for bisphenol A (BPA) monitoring based on Cu3BiS3 sensitized CuV2O6 nanocomposites with exceptional visible-light PEC activity. We implemented the integration of Cu3BiS3 nanosheet photosensitizer to sensitize the CuV2O6 nanowire structure that was synthesized utilizing a facile hydrothermal approach. The band gap alignment between Cu3BiS3 and CuV2O6 facilitated enduring PEC response yielding an efficient interfacial structure. The surface of the CuV2O6/Cu3BiS3 electrode was modified with BPA aptamer, enabling specific binding with BPA and precise quantification of its content. The developed aptamer sensors possess a wide detection range of 5.00 × 10-1 to 5.00 × 104 ng/mL, and a low detection limit of 1.60 × 10-1 ng/mL (at S/N = 3). After undergoing 20 testing cycles and enduring long-term storage, the sensor maintained its stability and showcased excellent repeatability and reproducibility. This study presents a promising methodology for the detection of BPA in environmental settings.

7.
J Integr Plant Biol ; 66(6): 1052-1067, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38501444

RESUMO

ACYL-CoA-BINDING PROTEINs (ACBPs) play crucial regulatory roles during plant response to hypoxia, but their molecular mechanisms remain poorly understood. Our study reveals that ACBP4 serves as a positive regulator of the plant hypoxia response by interacting with WRKY70, influencing its nucleocytoplasmic shuttling in Arabidopsis thaliana. Furthermore, we demonstrate the direct binding of WRKY70 to the ACBP4 promoter, resulting in its upregulation and suggesting a positive feedback loop. Additionally, we pinpointed a phosphorylation site at Ser638 of ACBP4, which enhances submergence tolerance, potentially by facilitating WRKY70's nuclear shuttling. Surprisingly, a natural variation in this phosphorylation site of ACBP4 allowed A. thaliana to adapt to humid conditions during its historical demographic expansion. We further observed that both phosphorylated ACBP4 and oleoyl-CoA can impede the interaction between ACBP4 and WRKY70, thus promoting WRKY70's nuclear translocation. Finally, we found that the overexpression of orthologous BnaC5.ACBP4 and BnaA7.WRKY70 in Brassica napus increases submergence tolerance, indicating their functional similarity across genera. In summary, our research not only sheds light on the functional significance of the ACBP4 gene in hypoxia response, but also underscores its potential utility in breeding flooding-tolerant oilseed rape varieties.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Ligação a DNA , Fosforilação , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética
8.
Anal Chem ; 95(38): 14317-14323, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37695886

RESUMO

Inspired by the signal accumulation of circular DNA strand displacement reactions (CD-SDRs) and the in situ generation of silver nanoclusters (AgNCs) from signature template sequences, a dual-signal integrated aptasensor was designed for microcystin-LR (MC-LR) detection. The aptamer was programmed to be included in an enzyme-free CD-SDR, which utilized MC-LR as the primer and outputted the H1/H2 dsDNA in a continuous manner according to the ideal state. Ingeniously, H1/H2 dsDNA was enriched with signature template sequences, allowing in situ generation of AgNCs signal probes. To enhance the signal amplification performance, co-reaction acceleration strategies and CRISPR-Cas12a nucleases were invoked. The H1/H2 dsDNA could trigger the incidental cleavage performance of CRISPR-Cas12a nucleases: cis-cleavage reduced signature template sequences for the synthetic AgNCs, while trans-cleavage enabled fluorescence (FL) analysis. Meanwhile, AuPtAg was selected as the substrate material to facilitate the S2O82- reduction reaction for enhancing the electrochemiluminescence (ECL) basal signals. ECL and FL detection do not interfere with each other and have improved accuracy and sensitivity, with limits of detection of 0.011 and 0.023 pmol/L, respectively. This widens the path for designing dual-mode sensing strategies for signal amplification.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanopartículas Metálicas , DNA Circular , Prata , DNA/genética , Aptâmeros de Nucleotídeos/genética , Limite de Detecção
9.
Anal Chem ; 95(13): 5695-5701, 2023 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-36952259

RESUMO

The controlled release strategy can make the constructed sensor have the function of self-on/off, which has an obvious effect on improving the sensitivity in immunoassays. Metal organic gels (MOGs) are the most noteworthy. They are materials with ultrahigh surface area, highly dispersed atomical metal sites, and well-defined porosity and can be used as an efficient luminophore to cause the developed sensor to have good hydrophilicity and adjustability, thus further improving the detection sensitivity. In this work, a novel on/off electrochemiluminescence (ECL) gel aptasensor was constructed using the Cys-[Ru(dcbpy)3]2+ gel as a luminophore, ZnS quantum dots (QDs) as quenchers, and aminated mesoporous silica nanocontainers (SiO2-NH2) as carriers of controlled release for prostate specific antigen (PSA) detection. Specifically, the ssDNA and PSA aptamer made up clamp-like molecules to block holes of the SiO2-NH2 after encapsulating the quencher ZnS QDs. Because of the specific binding between the PSA antigen and aptamer, the clamp-like molecules of ssDNA and the PSA aptamer were disassembled. Finally, the release of ZnS QDs was triggered, thereby realizing a self-off mode of the ECL signals under a co-reactant-free environment by ECL resonance energy transfer (ECL-RET) between the Cys-[Ru(dcbpy)3]2+ and ZnS QDs. In addition, the quenching mechanism was confirmed by molecular orbitals from the theoretical calculation level. The detection limit of the gel aptasensor for PSA was as low as 1.01 fg/mL, showing excellent sensitivity and accuracy. These strategies provided a feasible idea for PSA and even other tumor marker immunoassays.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Pontos Quânticos , Humanos , Masculino , Antígeno Prostático Específico , Dióxido de Silício/química , Preparações de Ação Retardada , Medições Luminescentes , Pontos Quânticos/química , Oligonucleotídeos , Técnicas Eletroquímicas , Nanopartículas Metálicas/química
10.
Anal Chem ; 95(45): 16761-16770, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37905934

RESUMO

Copper nanoclusters (Cu NCs) are highly promising nanomaterials in the field of electrochemiluminescence (ECL). Nevertheless, their limited stability and efficiency have impeded their practical applications. Here, we introduced a novel supramolecular anchoring strategy resulting in the creation of exceptionally stable Cu NCs (CET-Cu NCs) with remarkable ECL properties. Specifically, CET-Cu NCs exhibited a relative ECL efficiency (ΦECL) of 62% based on the annihilation ECL efficiency of [Ru(bpy)3]2+ (100%), with tripropylamine employed as a coreactant. Moreover, CET-Cu NCs can generate ECL emission through multiple different paths, which enables them to serve as signal probes in a wider range of testing scenarios, thereby enhancing the reliability and robustness of sensing and analytical systems. To demonstrate the practical utility, CET-Cu NCs were selected as an ECL signal probe for a sensing platform that facilitated ultrasensitive detection of progesterone via oriented immobilization technology and antibody/aptamer sandwich assays. This study surmounted the barriers to the practical application of Cu NCs through the implementation of a supramolecular anchoring strategy, thereby providing enhanced utility of Cu NCs in ECL sensing and analysis.

11.
Biochem Biophys Res Commun ; 639: 134-141, 2023 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-36493556

RESUMO

In cyanobacteria and algae (but not plants), flavodoxin (Fld) replaces ferredoxin (Fd) under stress conditions to transfer electrons from photosystem I (PSI) to ferredoxin-NADP+ reductase (FNR) during photosynthesis. Fld constitutes a small electron carrier noncovalently bound to flavin mononucleotide (FMN), and also an ideal model for revealing the protein/flavin-binding mechanism because of its relative simplicity compared to other flavoproteins. Here, we report two crystal structures of apo-Fld from Synechococcus sp. PCC 7942, one dimeric structure of 2.09 Å and one monomeric structure of 1.84 Å resolution. Analytical ultracentrifugation showed that in solution, apo-Fld exists both as monomers and dimers. Our dimer structure contains two ligand-binding pockets separated by a distance of 45 Å, much longer than the previous structures of FMN-bound dimers. These results suggested a potential dimer-monomer transition mechanism of cyanobacterial apo-Fld. We further propose that the dimer represents the "standby" state to stabilize itself, while the monomer constitutes the "ready" state to bind FMN. Furthermore, we generated a new docking model of cyanobacterial Fld-FNR complex based on the recently reported cryo-EM structures, and mapped the special interactions between Fld and FNR in detail.


Assuntos
Anabaena , Cianobactérias , Flavodoxina/química , Flavodoxina/metabolismo , Ferredoxinas/metabolismo , Anabaena/metabolismo , Flavoproteínas , Ferredoxina-NADP Redutase/química , Cianobactérias/metabolismo , Oxirredução
12.
Breast Cancer Res Treat ; 199(3): 435-444, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37071267

RESUMO

PURPOSE: This study aimed to correlate clinicopathological parameters with survival outcomes in a cohort of patients diagnosed with malignant phyllodes tumors (MPTs). We also analyzed the malignancy grade of MPTs and investigated the prognostic significance of the malignancy grading system. METHODS: Clinicopathological parameters, malignancy grades, and clinical follow-up data of 188 women diagnosed with MPTs in a single-institution were analyzed. MPTs of the breast were grouped according to stromal atypia, stromal overgrowth, mitotic count, tumor differentiation, and necrosis. A Fleiss' kappa statistic was calculated to test the agreement between the pathologists for the grading of MPTs. Disease-free survival (DFS), distant metastasis-free survival (DMFS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared between groups using the log-rank test. Cox regression was carried out to identify factors predictive of locoregional recurrence (LRR), distant metastasis (DM) and death. RESULTS: A total of 188 MPTs were classified according to the malignancy grading system: 88 (46.8%) as low grade, 77 (41%) as an intermediate grade, and 23 (12.2%) as high grade. Excellent agreement between pathologists for the grading of MPTs (Fleiss' kappa 0.807). In our study population, the occurrence of DM and death were associated with the malignancy grade of MPTs (P < 0.001). Based on the DFS curves, the presence of heterologous elements (P = 0.025) and younger age (P = 0.014) were independent prognostic indicators. Additionally, the malignancy grade retained independent prognostic significance for predicting DMFS and OS (P < 0.001 and P = 0.009). CONCLUSIONS: Higher malignancy grade, presence of heterologous elements, younger age, larger tumor size, and recent rapid tumor growth are poor prognostic factors for MPTs of the breast. The malignancy grading system may be generalized in the future.


Assuntos
Neoplasias da Mama , Tumor Filoide , Humanos , Feminino , Tumor Filoide/patologia , Recidiva Local de Neoplasia , Prognóstico , Mama/patologia , Gradação de Tumores , Estudos Retrospectivos
13.
Breast Cancer Res Treat ; 199(1): 25-33, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36930346

RESUMO

PURPOSE: Multifocal or multicentric (MFMC) breast cancer is mainly focused on breast cancer patients with unknown BRCA status, the incidence and clinical relevance of MFMC disease in BRCA1/2 carriers is less explored to date. Our study was to investigate the incidence of MFMC disease in BRCA1/2 carriers and whether MFMC disease influences local recurrence and clinical outcomes. METHODS: In this retrospective study, 479 breast cancer patients with BRCA1/2 variants and 1437 age-matched noncarriers were enrolled and patients received either breast-conserving therapy (BCT) or mastectomy with or without radiotherapy. RESULTS: The rates of MFMC disease in BRCA1 and BRCA2 carriers, and noncarriers were 33.0% (61 of 185), 37.4% (110 of 294), and 31.2% (449 of 1437), respectively. MFMC disease in BRCA2 carriers was significantly higher than that in noncarriers (P = 0.039). After a median follow-up of 8.1 years, among patients treated with BCT, BRCA2 carriers with MFMC disease experienced a significantly higher rate of ipsilateral breast tumor recurrence (IBTR) than those with unifocal disease (16.7% vs 4.1%, P = 0.044). Moreover, BRCA2 carriers with MFMC disease had a significantly worse RFS (unadjusted hazard ratio [HR], 3.65 [95% CI 1.40-9.52]; P = 0.008), DRFS (unadjusted HR, 3.07 [95% CI 1.07-8.80]; P = 0.037), and OS (unadjusted HR, 4.96 [95% CI 1.18-20.02]; P = 0.029) than those with unifocal disease when treated with BCT. CONCLUSION: MFMC breast cancer is more common in BRCA2 carriers, and BRCA2 carriers with MFMC disease treated with BCT exhibit a higher rate of IBTR and may have a poor survival.


Assuntos
Neoplasias da Mama , Neoplasias Mamárias Animais , Humanos , Animais , Feminino , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Neoplasias da Mama/tratamento farmacológico , Proteína BRCA1/genética , Mastectomia , Estudos Retrospectivos , Proteína BRCA2/genética , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/cirurgia , Neoplasias Mamárias Animais/cirurgia , Mutação
14.
Opt Express ; 31(10): 17017-17026, 2023 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-37157767

RESUMO

The determination of electron spin polarization by controlling the atomic population distributions of ground states has been proposed. The polarization could be deduced by generating different population symmetries by polarized lights. The polarization of the atomic ensembles was decoded from optical depth in different transmissions of linearly and elliptic polarized lights. The feasibility of the method has been validated theoretically and experimentally. Moreover, the influences of relaxation and magnetic fields are analyzed. The transparency induced by high pump rates are investigated experimentally, and the influences of ellipticity of lights are also discussed. The in-situ polarization measurement was achieved without changing optical path of atomic magnetometer, which provides a new way to interrogate the performance of atomic magnetometer and in-situ monitoring the hyperpolarization of nuclear spins for atomic co-magnetometer.

15.
Chemphyschem ; 24(20): e202300536, 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37525230

RESUMO

The electrocatalytic nitrate reduction reaction (NO3 - RR) enables the reduction of nitrate to ammonium ions under ambient conditions. It was considered as an alternative reaction for the production of ammonia (NH3 ) in recent years. In this paper, we report that the Fe doping CoS2 nanoarrays can effectively catalyze the formation of NH3 from nitrate (NO3 - ) under ambient conditions. This is mainly due to the increase of the NO3 - reaction active site by Fe doping and the porous nanostructure of the catalyst, which greatly improves the catalytic activity. Specifically, at -0.9 V vs. RHE, the NH3 yield rate (RNH3 ) of Fe-CoS2 /CC is 17.8×10-2  mmol h-1 cm-2 with Faraday Efficiency (FE) of 88.93 %. Besides, such catalyst shows good durability and catalytic stability, which provides the possibility for the future application of electrocatalytic NH3 production.

16.
J Org Chem ; 88(7): 4442-4451, 2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-36896970

RESUMO

A robust palladium-catalyzed decarbonylative alkynylation of aryl anhydrides is reported. The catalytic system of Pd(OAc)2/XantPhos and DMAP as a nucleophilic additive has been identified as effective promoters for decarbonylative Sonogashira alkynylation. Recently, activated esters, amides, and carboxylic acids were applied as electrophiles in transition-metal-catalyzed decarbonylative alkynylation. The present process expands this reactivity to readily available aryl anhydrides as electrophilic reagents for decarbonylative alkynylation. It is worth noting that the reactivity of aryl anhydrides is higher than that of esters, amides, and carboxylic acids in decarbonylative alkynylation. Broad substrate scope and excellent functional group tolerance are presented, demonstrating that aryl anhydrides may serve as a general and practical class of electrophiles to achieve the synthesis of internal alkynes.

17.
Molecules ; 28(6)2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36985559

RESUMO

Rapid RAFT polymerization can significantly improve production efficiency of PAM with designed molecular structure. This study shows that ideal Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization of acrylamide is achieved in dimethyl sulfoxide (DMSO) solution at 70 °C. The key to success is the appropriate choice of both a suitable RAFT chain transfer agent (CTA) and initiating species. It is illustrated that dodecyl trithiodimethyl propionic acid (DMPA) is a suitable trithiocarbonate RAFT CTA and is synthesized more easily than other CTAs. Compared to other RAFT processes of polymers, the reaction system shortens reaction time, enhances conversion, and bears all the characteristics of a controlled radical polymerization. The calculation result shows that high concentrations can reduce high conversions, accelerate the reaction rate, and widen molecular weight distributions slightly. This work proposes an excellent approach for rapid synthesis of PAMs with a restricted molecular weight distribution.

18.
Analyst ; 147(21): 4768-4776, 2022 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-36149312

RESUMO

Cardiac troponin I (cTnI) is one of the structural subunits of cardiac troponin complexes and a significant biomarker of acute myocardial infarction (AMI). Therefore, a sensitive detection of cTnI in the early stages is of great significance. Here, a sensitive sandwiched electrochemiluminescence (ECL) immunosensor was built for the detection of cTnI, where molybdenum disulfide@cuprous oxide-silver nanoparticles (MoS2@Cu2O-Ag) immobilized cTnI the capture antibody (Ab1), and cerium-doped zinc oxide@nitrogen-doped graphene quantum dots (Ce:ZnO@NGQDs) loaded the signal antibody (Ab2). The MoS2@Cu2O-Ag nanoparticles not only indicated excellent electroconductivity and biocompatibility but also provided a large specific surface. Ce:ZnO as a co-reaction accelerator can convert the Ce4+ ↔ Ce3+ reaction and might increase the rate of electron exchange to accomplish signal enhancement. Under optimum conditions, the sensor possessed a wide linear range from 10 pg mL-1 to 100 ng mL-1, and the LOD was 2.90 fg mL-1 (S/N = 3). In addition, the sensor plays a good role in serum detection, indicating that it has potential for application in the detection of biomolecules.


Assuntos
Técnicas Biossensoriais , Cério , Grafite , Nanopartículas Metálicas , Óxido de Zinco , Técnicas Eletroquímicas , Eletrodos , Grafite/química , Imunoensaio , Limite de Detecção , Medições Luminescentes , Nanopartículas Metálicas/química , Molibdênio , Nitrogênio/química , Prata/química , Troponina I , Óxido de Zinco/química , Pontos Quânticos
19.
Appl Opt ; 61(1): 149-156, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35200814

RESUMO

This paper presents a single-beam atomic magnetic field measurement gradiometer, which is a highly sensitive magnetic field gradient measuring instrument based on the atom spin-exchange relaxation-free (SERF) effect. The reflective detection optical path structure is adopted. The spin precession signals of an atom under incident and reflected light are different. There is also a difference in the corresponding magnetic field distribution. The final measurement of magnetic field gradients is conducted based on the different magnetic field distributions. The single-beam high-sensitive magnetic field gradiometers based on the atomic SERF effect are more sensitive than conventional two-probe magnetic field gradiometers or two-beam magnetic field gradiometers. The gradiometers are not affected by a difference in the detected optical power in the single-beam detection light measurements. The reflector uses an angular cone prism for two-dimensional magnetic field gradient measurements and is simple to construct. The single-beam highly sensitive magnetic field gradient measurement instrument based on the atomic SERF effect has a reflective detection optical path structure. It uses a quarter-wave plate to achieve the initial signal phase elimination of both incident and reflected signal and an angular cone prism as a reflector to achieve two-dimensional measurement.

20.
J Cell Mol Med ; 25(3): 1783-1795, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33470533

RESUMO

Neuregulin-1 (NRG-1) is reported to be cardioprotective through the extracellular-regulated protein kinase (ERK) 1/2 pathway in myocardial ischaemia-reperfusion injury (MIRI). NOX4-induced ROS activated NLRP3 inflammasome and exacerbates MIRI. This study aims to investigate whether NRG-1 can suppress NOX4 by ERK1/2 and consequently inhibit the NLRP3/caspase-1 signal in MIRI. The myocardial infarct size (IS) was measured by TTC-Evans blue staining. Immunohistochemical staining, real-time quantitative PCR (RT-qPCR) and Western blotting were used for detection of the factors, such as NOX4, ERK1/2, NLRP3, caspase-1 and IL-1ß .The IS in the NRG-1 (3 µg/kg, intravenous) group was lower than that in the IR group. Immunohistochemical analysis revealed NRG-1 decreased 4HNE and NOX4. The RT-qPCR and Western blot analyses revealed that NRG-1 mitigated the IR-induced up-regulation of NOX4 and ROS production. Compared with the IR group, the NRG-1 group exhibited a higher level of P-ERK1/2 and a lower level of NLRP3. In the Langendorff model, PD98059 inhibited ERK1/2 and up-regulated the expression of NOX4, NLRP3, caspase-1 and IL-1ß, which exacerbated oxidative stress and inflammation. In conclusion, NRG-1 can reduce ROS production by inhibiting NOX4 through ERK1/2 and inhibit the NLRP3/caspase-1 pathway to attenuate myocardial oxidative damage and inflammation in MIRI.


Assuntos
Caspase 1/metabolismo , Traumatismo por Reperfusão Miocárdica/etiologia , Traumatismo por Reperfusão Miocárdica/metabolismo , NADPH Oxidase 4/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Neuregulina-1/metabolismo , Estresse Oxidativo , Animais , Biomarcadores , Biópsia , Modelos Animais de Doenças , Expressão Gênica , Imuno-Histoquímica , Masculino , Modelos Biológicos , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/diagnóstico por imagem , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/metabolismo , Miocárdio/patologia , Neuregulina-1/genética , Ratos
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