RESUMEN
The detection of lysine acetyltransferases is crucial for diagnosing and treating lung cancer, highlighting the necessity for highly efficient detection methods. We developed a portable, highly accurate, and sensitive technique using fast-scan cyclic voltammetry (FSCV) to determine the activity of the lysine acetyltransferase TIP60, employing a novel miniature electrochemical sensor. This approach involves a compact electrochemical cell, merely 3 mm in diameter, that holds solutions up to 50 µL, equipped with a conductive indium tin oxide working electrode. Uniquely, this system operates on a two-electrode model compatible with the FSCV, obviating the traditional requirement for a reference electrode. The system detects TIP60 activity through the continuous generation of CoA molecules that engage in reactions with Cu(II), thereby significantly improving the accuracy of the acetylation analysis. Remarkably, the detection limit achieved for TIP60 is notably low at 3.3 pg/mL (S/N = 3). The results show that the reversible dynamic acetylation can be effectively regulated by inhibitor incubation and glucose stimulation. This cutting-edge strategy enhances the analysis of a broad spectrum of biomarkers by modifying the responsive unit, and its miniaturization and portability significantly amplify its applicability in biomedical research, promising it to be a versatile tool for early diagnostic and therapeutic interventions in lung cancer.
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Neoplasias Pulmonares , Lisina Acetiltransferasas , Humanos , Neoplasias Pulmonares/diagnóstico , Técnicas ElectroquímicasRESUMEN
Glyphosate is a widely used herbicide and crop desiccant. However, whether its extensive use has any effect on the species diversity of nontarget organisms is still unclear. In this study, we used the silkworm, Bombyx mori, as the research subject, and performed RNA sequencing to analyze the transcriptional profile of silkworm midgut after exposure to glyphosate at 2975.20 mg/L (a concentration commonly used at mulberry fields). A total of 125 significantly differentially expressed genes (DEGs) were detected in the midgut of glyphosate-exposed silkworm (q < 0.05), of which 53 were upregulated and 72 were downregulated. Gene ontology enrichment analysis showed that the DEGs were mainly enriched in biological process, cellular component, and molecular function. Kyoto encyclopedia of genes and genomes analysis showed that the differential genes were mainly related to oxidative stress, nutrient metabolism, and immune defense pathways, including oxidative stress-related Cat and Jafrac1, nutrient metabolism-related Fatp and Scpx, and immune-related CYP6AN2, UGT40B4, CTL11, serpin-2, and so forth. Experimental verification showed that glyphosate exposure led to a 4.35-fold increase in the mortality of silkworm after Beauveria bassiana infection, which might be caused by the decreased PO (phenoloxidase) activity and impaired immunity. These results provide evidence for the potential effects of residue glyphosate on the physiological functions of silkworm, and also provide a reference for the biosafety evaluation of glyphosate.
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Bombyx , Perfilación de la Expresión Génica , Animales , Perfilación de la Expresión Génica/métodos , Bombyx/genética , Transcripción Genética , Inmunidad , GlifosatoRESUMEN
We developed an axis-mode donor-DNA-acceptor electrochemical system to distinguish whether electron transfer in DNA occurs by tunneling or hopping. In the axis-mode, rigid stem-loop DNA was designed with the redox probe Ag+ embedded at the axis of the strand through a C-Ag+-C mismatch, which was immobilized onto the electrode surface in a saturated manner. Thus, the rotation, swing, and bending of the DNA strand were restricted and then the number of Ag+, the distance L between Ag+ and the electrode, and the chemical environment could be precisely controlled. In addition, fast scan cyclic voltammetry was applied to realize the in situ redox reaction of Ag+, without diffusion away from the electrode and the ensuing deconstruction of the stem-loop DNA. In this case, as a direct indicator of rate, the peak Faradaic current ip was extracted and used to fit the tunneling mechanism i â exp (-ßL) and the hopping mechanism i â L-η. The value of ß was determined to be 0.100 Å-1, which is consistent with the range of 0.1â¼1.5 Å-1 reported previously, while η was determined to be 0.677, which is completely beyond the correct range of 1 ≤ η ≤ 2, demonstrating that electron transfer in DNA occurs by tunneling instead of hopping or that tunneling dominates. Additionally, current additivity and the irrelevance of the base sequence illustrate this point again. Thus, the possibility of independent parallel tunneling currents in DNA strands is revealed, which is helpful for recognizing the feasibility of DNA-based wires and devices.
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ADN , Electrones , Transporte de Electrón , Oxidación-Reducción , ElectrodosRESUMEN
We report an electrochemical biosensor based on the supramolecular host-guest recognition between cucurbit[7]uril (CB[7]) and L-phenylalanine-Cu(II) complex for pyrophosphate (PPi) and alkaline phosphatase (ALP) analysis. First, L-Phe-Cu(II) complex is simply synthesized by the complexation of Cu(II) (metal node) with L-Phe (bioorganic ligand), which can be immobilized onto CB[7] modified electrode via host-guest interaction of CB[7] and L-Phe. In this process, the signal of the complex-triggered electro-catalytic reduction of H2 O2 can be captured. Next, due to the strong chelation between PPi and Cu(II), a biosensing system of the model "PPi and Cu(II) premixing, then adding L-Phe" was designed and the platform was applied to PPi analysis by hampering the formation of L-Phe-Cu(II) complex. Along with ALP introduction, PPi can be hydrolyzed to orthophosphate (Pi), where abundant Cu(II) ions are released to form L-Phe-Cu(II) complex, which gives rise to the catalytic reaction of complex to H2 O2 reduction. The quantitative analysis of H2 O2 , PPi and ALP activity was achieved successfully and the detection of limits are 0.067â µM, 0.42â µM and 0.09 mU/mL (S/N=3), respectively. With its high sensitivity and selectivity, cost-effectiveness, and simplicity, our analytical system has great potential to for use in diagnosis and treatment of ALP-related diseases.
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Fosfatasa Alcalina , Difosfatos , Difosfatos/química , Ligandos , Cobre/química , FenilalaninaRESUMEN
In this paper, based on the fluorescence of carbon quantum dots (CQDs) quenched by mercury ions (Hg2+ ) and the nonresponse of Hg2+ to rhodamine B fluorescence, a dual emission ratio fluorescence sensor was constructed to realize the quantitative detection of Hg2+ . Under excitation at 365 nm, the fluorescence spectrum showed double emission peaks at 437 nm and 590 nm, corresponding to the fluorescence emissions of CQDs and rhodamine B, respectively. This method quantitatively detected Hg2+ based on the linear relationship between the ratio of the intensities of the two emission peaks F437 /F590 and the concentration of Hg2+ . The detection range was 10-70 nM, and the limit of detection (S/N = 3) was 3.3 nM. In addition, this method could also realize the qualitative and semiquantitative detection of Hg2+ according to the fluorescence colour change of the probe under ultraviolet light. After various evaluations, the method could be successfully applied to the quantitative and visual detection of Hg2+ in tap water, and demonstrated excellent selectivity, anti-interference performance, and repeatability of the method.
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Mercurio , Puntos Cuánticos , Carbono , Colorantes Fluorescentes , Iones , Límite de Detección , Espectrometría de FluorescenciaRESUMEN
An electrochemical aptasensor for ultrasensitive detection of Staphylococcus aureus (SA) has been developed based on stepwise signal amplification. In the sample processing stage, the specific recognition between SA and aptamer triggers the enzyme-assisted cyclic cleavage to produce a large amount of target DNA (tDNA), realizing the first-level signal amplification. In the sensor assembly stage, tDNA induces a catalytic hairpin assembly (CHA) cycle to capture much more hairpin DNA H2 labeled by the electrochemical tag ferrocene, bringing the second-level signal amplification. In the signal detection stage, ferrocene is quasi-adsorbed on the electrode surface, and a high redox peak current linearly increasing with the scan rate up to 1000 V/s has been obtained by fast scan cyclic voltammetry (FSCV), achieving the third-level signal amplification. Under the optimized experimental conditions, the linear range and detection limit are 1 ~ 108 CFU/mL and 0.3 CFU/mL, respectively. The sensor has good reproducibility, stability, and sensitivity, affording practical sample detection. This detection principle is widely applicable to other pathogens, and provides a new path for the establishment of highly sensitive detection strategies.
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Aptámeros de Nucleótidos , Técnicas Biosensibles , ADN , Técnicas Electroquímicas , Oro , Metalocenos , Reproducibilidad de los Resultados , Staphylococcus aureusRESUMEN
A Faraday cage-type aptasensor has been developed for dual-mode detection of a common bacterial pathogen Vibrio parahaemolyticus (VP) by electrochemiluminescence (ECL) and differential pulse voltammetry (DPV), using a multi-functionalized material Pb2+-Ru-MOF@Apt2 as signal unit. The recognition aptamer Apt2 recognizes VP; specifically, ruthenium-based metal organic framework (Ru-MOF) and lead ions (Pb2+) embedded produce an ECL signal at a working potential from 0 to 1.5 V and DPV signal from - 0.3 to - 0.8 V vs. Ag/AgCl. Since Ru-MOF is a two-dimensional conductive material signal unit overlapped onto the electrode surface to form a Faraday cage-type aptasensor. Thus, electrons could be easily exchanged between electrode and signal tags without being hindered by micron-size VP, resulting in a high detection sensitivity with a detection limit of 1.7 CFU mL-1. In addition, dual-mode detection was achieved, improving the accuracy and reliability of rapid field detection. Stability and selectivity were also satisfactory. The tests of real samples indicate that this Faraday cage-type aptasensor is suited for rapid detection of VP and analog pathogens and shows great potential in food safety. Graphical abstract.
RESUMEN
Histone acetylase (HAT p300), which has aroused great concern in fundamental research and clinical applications, serves as one class of significant tumor markers. In our work, a sensitive electrochemical immunoassay for testing HAT p300 based on both graphene-assisted supported AuPd nanomaterial (AuPd@GO composite) and a typical amperometric i-t technique with fast response is developed favorably. The AuPd@GO-based sensing mechanisms are distributed as follows: the HAT p300 derived acetylation reaction occurs at the customized peptide-immobilized electrode; the AuPd@GO composite acts as carrier to immobilize acetyl antibody, thus constructing a sandwich-type electrochemical immunosensor via an antigen and antibody interaction; importantly, a distinct electrochemical signal could be caught due to the AuPd@GO nanomaterial with a favorable electrocatalytic property to the commercialized 3,3,5',5'-tetramethyl benzidine solution (TMB). Taking advantage of AuPd@GO composite, the established immunosensor displays a wide linear range from 1 pM to 1000 nM, and the detection limit is 0.5 pM (S/N = 3) for HAT p300. Next, the biosensor is also used to analyze the inhibitor of HAT p300 successfully, which is promising for promoting the development of electrochemical HAT-related biodetection and drug discovery. Graphical abstract A sensitive electrochemical immunoassay for testing HAT p300 based on both graphene-assisted supported AuPd nanomaterial (AuPd@GO composite) and a typical amperometric i-t technique with fast response is developed favorably.
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Técnicas Electroquímicas/instrumentación , Inhibidores Enzimáticos/análisis , Oro/química , Grafito/química , Histona Acetiltransferasas/análisis , Nanopartículas del Metal/química , Paladio/química , Secuencia de Aminoácidos , Técnicas Biosensibles , Histona Acetiltransferasas/antagonistas & inhibidores , Límite de Detección , Péptidos/química , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: Associations between polymorphisms in vitamin D receptor (VDR)/vascular endothelial growth factor (VEGF)/interleukin-18 (IL-18)/mannose-binding lectin (MBL) and susceptibility to hepatocellular carcinoma (HCC) were already explored by many studies, yet the results of these studies were inconsistent. The aim of this meta-analysis was to better clarify associations between polymorphisms in VDR/VEGF/IL-18/MBL and HCC by combing the results of all relevant studies. METHODS: Eligible publications were searched from PubMed, Embase, WOS, and CNKI. We used Review Manager to combine the results of individual studies. RESULTS: Thirty studies were included in this study. Combined results revealed that VDR rs7975232, VDR rs2228570, VEGF rs699947, VEGF rs3025039, IL-18 rs1946518, and MBL rs7096206 polymorphisms were all significantly associated with HCC in the overall pooled population. We also obtained similar significant associations for VDR rs7975232, VDR rs2228570, IL-18 rs1946518, and MBL rs7096206 polymorphisms in Asians. CONCLUSIONS: Collectively, this meta-analysis proved that VDR rs7975232, VDR rs2228570, VEGF rs699947, VEGF rs3025039, IL-18 rs1946518, and MBL rs7096206 polymorphisms may confer susceptibility to HCC in certain populations.
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Pueblo Asiatico/genética , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Carcinoma Hepatocelular/patología , Predisposición Genética a la Enfermedad , Humanos , Interleucina-18/genética , Neoplasias Hepáticas/patología , Lectina de Unión a Manosa/genética , Polimorfismo de Nucleótido Simple , Receptores de Calcitriol/genética , Factor A de Crecimiento Endotelial Vascular/genéticaRESUMEN
Novel water-soluble green fluorescent carbon nanodots (CNs) using methacrylic acid and m-phenylenediamine as precursors were first synthesized using a one-pot hydrothermal method. Red fluorescent lanthanide complexes were prepared using lanthanide ion Eu3+ and pyridine-2,6-dicarboxylic acid. The optical properties of CNs were characterized using ultraviolet visible (UV) spectra and fluorescence spectra, microscopic morphology was characterized using transmission electron microscopy (TEM) and dynamic light scattering (DLS), and the elemental composition was characterized using Fourier transform-infrared spectroscopy (FT-IR) and X-ray photoelectron spectra (XPS). The fluorescence spectra of the lanthanide complexes were also measured. A simple strategy was developed to prepare UV light-tunable fluorescent inks and polymer hydrogels films based on CNs and lanthanide complexes. The fluorescent inks and polymer hydrogels films could be repeatedly switched between green and red fluorescence. The change of color depended on luminescence of the CNs and the lanthanide complexes under 254 and 365 nm UV light, respectively. The UV light-tunable fluorescent inks and polymer hydrogels films could enhance its anti-counterfeiting function for data and information.
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Hidrogel de Polietilenoglicol-Dimetacrilato/química , Tinta , Elementos de la Serie de los Lantanoides/química , Nanotubos de Carbono/química , Polímeros/química , Rayos Ultravioleta , Fluorescencia , Tamaño de la Partícula , Espectrometría de Fluorescencia , Espectrofotometría UltravioletaRESUMEN
A method is described for combined magnetic solid phase microextraction and electrochemiluminescent (ECL) detection of the antibiotic tetracycline. A nanocomposite of type Fe3O4@SiO2@ZnO was used as the sorbent. Tetracycline has a strong affinity for Zn(II) ion and therefore is well extracted by this sorbent. The loaded sorbent can be magnetically removed. The extraction efficiency at a 1.0 µM tetracycline concentration is around 88%. Detection is based on the use of carbon nanodots that were prepared form urea and ethylenediaminetetraacetic acid as raw materials. The electrochemical probe Ru(bpy)32+ was added to generate double ECL when scanning the potential between -3.5 and + 2 V. The two ECL signals decreased with the increase of tetracycline concentration. Under optimized experimental conditions, the ratio of the two signals is linearly related to the logarithm of the tetracycline concentration in the range from 1.0 nM to 0.1 mM, with a 0.47 nM detection limit. The method was successfully applied to the determination of tetracycline in spiked milk. It exhibited good sensitivity, selectivity and accuracy due to ratiometric read-out and prior preconcentration of analyte. Graphical abstract Tetracycline (TC) has a strong affinity for Zn(II) ion and is well extracted by the Fe3O4@SiO2@ZnO nanocomposite. Ru(bpy)32+ can generate double electrochemiluminescence signals based on the use of carbon nanodots (C-dots) as coreactant. The two signals decrease with the increase of tetracycline concentration. [Ru(bpy)32+]* stands for excited state Ru(bpy)22+.
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Antibacterianos/análisis , Nanopartículas de Magnetita/química , Nanocompuestos/química , Compuestos Organometálicos/química , Dióxido de Silicio/química , Tetraciclina/análisis , Óxido de Zinc/química , Animales , Antibacterianos/química , Carbono/química , Técnicas Electroquímicas , Mediciones Luminiscentes , Fenómenos Magnéticos , Leche/química , Microextracción en Fase Sólida , Tetraciclina/químicaRESUMEN
Protein p300 is a transcriptional co-activator that participates in many physiological processes including cell cycle control, differentiation and apoptosis. It serves (a) as a protein bridge that links specific transcription factors to the fundamental transcription machinery, (b) as a scaffold to complete multiple transcription cofactors, and (c) as an enzyme for acetylating histone and non-histone proteins. An ultrasensitive electrochemiluminescence (ECL) immunosensor is described here that is based on the use of a magnetic glassy carbon electrode modified with tetrahedral DNA with hollow structure, graphene oxide (GO) and gold nanocrystals. The use of a GO monolayer allows for greater carrying capacity and warrants a wider outer Helmholtz plane. Strong and stable ECL signals were achieved due to antigen-antibody interaction by using the ECL probe Ru(phen)32+. This immunosensor has a response that covers the 0.005 to 80 nM p300 concentration range and has a 1 pM detection limit. It was exploited for the determination of p300 in HeLa cell lysate and (spiked) serum. Graphical abstract Schematic presentation of an ultrasensitive Faraday-cage electrochemiluminescence immunosensor toward the transcriptional co-activator p300 analysis is presented based on a graphene oxide monolayer and tetrahedral DNA-mediated signal amplification.
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Proteína p300 Asociada a E1A/análisis , Oro/química , Grafito/química , Nanopartículas del Metal/química , Nanocompuestos/química , Técnicas Biosensibles/métodos , ADN/química , Técnicas Electroquímicas/métodos , Electrodos , Colorantes Fluorescentes/química , Células HeLa , Humanos , Inmunoensayo/métodos , Límite de Detección , Mediciones Luminiscentes/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Compuestos Organometálicos/química , Fenantrolinas/químicaRESUMEN
Electrochemical methods allow fast and inexpensive analysis of enzymatic activity. Here, a simple and yet efficient "signal-on" electrochemical assay for sensitive, label-free detection of DNA-related enzyme activity was established on the basis of terminal deoxynucleotidyl transferase (TdT)-mediated extension strategy. TdT, which is a template-independent DNA polymerase, can catalyze the sequential addition of deoxythymidine triphosphate (dTTP) at the 3'-OH terminus of single-stranded DNA (ssDNA); then, the TdT-yield T-rich DNA nanowires can be employed as the synthetic template of copper nanoclusters (CuNCs). Grown DNA nanowires-templated CuNCs (noted as DNA-CuNCs) were attached onto graphene oxide (GO) surface and exhibited unique electrocatalytic activity to H2O2 reduction. Under optimal conditions, the proposed biosensor was utilized for quantitatively monitoring TdT activity, with the observed LOD of 0.1 U/mL. It also displayed high selectivity to TdT with excellent stability, and offered a facile, convenient electrochemical method for TdT-relevant inhibitors screening. Moreover, the proposed sensor was successfully used for BamHI activity detection, in which a new 3'-OH terminal was exposed by the digestion of a phosphate group. Ultimately, it has good prospects in DNA-related enzyme-based biochemical studies, disease diagnosis, and drug discovery. Graphical Abstract Extraordinary TdT-generated DNA-CuNCs are synthesized and act as a novel electrochemical sensing platform for sensitive detection of TdT and BamHI activity in biological environments.
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Cobre/química , ADN Nucleotidilexotransferasa/metabolismo , ADN/metabolismo , Desoxirribonucleasa BamHI/metabolismo , Técnicas Electroquímicas/métodos , Pruebas de Enzimas/métodos , Nanoestructuras/química , Técnicas Biosensibles/métodos , ADN/química , ADN Nucleotidilexotransferasa/análisis , ADN de Cadena Simple/química , ADN de Cadena Simple/metabolismo , Desoxirribonucleasa BamHI/análisis , Límite de Detección , Nanocables/químicaRESUMEN
A novel Faraday cage-type electrochemiluminescence (ECL) immunosensor devoted to the detection of Vibrio vulnificus (VV) was fabricated. The sensing strategy was presented by a unique Faraday cage-type immunocomplex based on immunomagnetic beads (IMBs) and multi-functionalized graphene oxide (GO) labeled with (2,2'-bipyridine)(5-aminophenanthroline)ruthenium (Ru-NH2). The multi-functionalized GO could sit on the electrode surface directly due to the large surface area, abundant functional groups, and good electronic transport property. It ensures that more Ru-NH2 is entirely caged and become "effective," thus improving sensitivity significantly, which resembles extending the outer Helmholtz plane (OHP) of the electrode. Under optimal conditions, the developed immunosensor achieves a limit of detection as low as 1 CFU/mL. Additionally, the proposed immunosensor with high sensitivity and selectivity can be used for the detection of real samples. The novel Faraday cage-type method has shown potential application for the diagnosis of VV and opens up a new avenue in ECL immunoassay. Graphical abstract Faraday cage-type immunoassay mode for ultrasensitive detection by extending OHP.
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Técnicas Electroquímicas/métodos , Grafito/química , Separación Inmunomagnética/métodos , Mediciones Luminiscentes/métodos , Compuestos Organometálicos/química , Fenantrolinas/química , Alimentos Marinos/microbiología , Vibrio vulnificus/aislamiento & purificación , Análisis de los Alimentos/métodos , Humanos , Límite de Detección , Óxidos/química , Agua de Mar/microbiología , Vibriosis/microbiologíaRESUMEN
Protein acetylation of histone is an essential post-translational modification (PTM) mechanism in epigenetic gene regulation, and its status is reversibly controlled by histone acetyltransferases (HATs) and histone deacetylases (HDACs). Herein, we have developed a sensitive and label-free time-resolved luminescence (TRL) biosensor for continuous detection of enzymatic activity of HATs and HDACs, respectively, based on acetylation-mediated peptide/DNA interaction and Tb(3+)/DNA luminescent probes. Using guanine (G)-rich DNA-sensitized Tb(3+) luminescence as the output signal, the polycationic substrate peptides interact with DNA with high affinity and subsequently replace Tb(3+), eliminating the luminescent signal. HAT-catalyzed acetylation remarkably reduces the positive charge of the peptides and diminishes the peptide/DNA interaction, resulting in the signal on detection via recovery of DNA-sensitized Tb(3+) luminescence. With this TRL sensor, HAT (p300) can be sensitively detected with a wide linear range from 0.2 to 100 nM and a low detection limit of 0.05 nM. The proposed sensor was further used to continuously monitor the HAT activity in real time. Additionally, the TRL biosensor was successfully applied to evaluating HAT inhibition by two specific inhibitors, anacardic acid and C464, and satisfactory Z'-factors above 0.73 were obtained. Moreover, this sensor is feasible to continuously monitor the HDAC (Sirt1)-catalyzed deacetylation with a linear range from 0.5 to 500 nM and a detection limit of 0.5 nM. The proposed sensor is a convenient, sensitive, and mix-and-read assay, presenting a promising platform for protein acetylation-targeted epigenetic research and drug discovery.
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Técnicas Biosensibles/métodos , ADN/química , Histona Acetiltransferasas/metabolismo , Histona Desacetilasas/metabolismo , Histonas/metabolismo , Sustancias Luminiscentes/química , Terbio/química , Acetilación , ADN de Cadena Simple/química , Inhibidores Enzimáticos/farmacología , Guanina/química , Histona Acetiltransferasas/antagonistas & inhibidores , Límite de Detección , Modelos Moleculares , Conformación de Ácido Nucleico , Péptidos/metabolismo , Procesamiento Proteico-Postraduccional , Factores de TiempoRESUMEN
A sensitive fluorescence turn-on biosensing platform for protein kinase activity assay has been developed based on fluorescence resonance energy transfer (FRET) between a fluorophore labeled peptide and a water soluble cationic conjugated polymer (CCP). The CCP-based assay is based on the electrostatic interaction between the peptide and the CCP. The FRET efficiency will change with the changing charges around the peptide after phosphorylation. The feasibility of this method has been demonstrated by sensitive measurement of the activity of cAMP-dependent protein kinase (PKA) with a low detection limit (0.3 mU µL(-1)). Based on its simple mechanism, this assay is also sensitive and robust enough to be applied to the evaluation of PKA inhibitor H-89. The IC50 value, the half maximal inhibitory concentration, was 40 nM. Furthermore, our method has excellent selectivity. CCP-based assay is sensitive, versatile, cost-effective and easy to operate, so, this method is a promising candidate for kinase activity assay and inhibitor screening.
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Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Transferencia Resonante de Energía de Fluorescencia/métodos , Colorantes Fluorescentes/química , Péptidos/química , Polímeros/química , Proteínas Quinasas Dependientes de AMP Cíclico/análisis , Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Evaluación Preclínica de Medicamentos/métodos , Pruebas de Enzimas/métodos , Fluorescencia , Colorantes Fluorescentes/metabolismo , Humanos , Isoquinolinas/farmacología , Límite de Detección , Péptidos/metabolismo , Fosforilación , Polímeros/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Sulfonamidas/farmacologíaRESUMEN
In this study, a low field nuclear magnetic resonance (LF-NMR) homogeneous sensor was constructed for detection of Escherichia coli (E. coli) based on the copper metabolism of E. coli triggered click reaction. When live E. coli was present, a large amount of Cu2+ ions were transformed into Cu+ via copper metabolism, which then catalyzed a Cu+-catalyzed azide-alkyne cycloaddition (CuAAC) reaction between two materials, azide group modified gadolinium oxide nanorods (Gd2O3-Az) and PA-GO@Fe3O4 i.e., graphene oxide (GO) loaded with large amounts of alkynyl (PA) groups and Fe3O4 nanoparticles simultaneously. After magnetic separation, unbound Gd2O3-Az was dissolved by added hydrochloric acid (HCl) to generate homogeneous Gd3+ solution, enabling homogeneous detection of E. coli. Triple signal amplification was achieved through the CuAAC reaction induced by E. coli copper metabolism, functional nanomaterials, and HCl assisted homogeneous detection. Under the optimal experimental conditions, the linear range and limit of detection (LOD) for E. coli were 10-1.0 × 107 CFU/mL and 3.5 CFU/mL, respectively, and the relative standard deviations (RSDs) were all less than 2.8 %. In addition, the sensor has satisfactory selectivity, stability and practical sample application capability, providing a new approach for the LF-NMR detection of food-borne pathogenic bacteria.
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Alquinos , Azidas , Química Clic , Cobre , Escherichia coli , Grafito , Escherichia coli/aislamiento & purificación , Cobre/química , Azidas/química , Grafito/química , Alquinos/química , Espectroscopía de Resonancia Magnética , Reacción de Cicloadición , Gadolinio/química , Límite de Detección , Nanotubos/químicaRESUMEN
Unsafe food additives pose a significant threat to global health, especially in developing countries. Many existing methods rely on clean laboratories, complicated optics equipment, trained personnel and lengthy detection time, which are not suitable for onsite food safety inspections in emergency situations, peculiarly in impoverished areas. In this paper, a fast and visual onsite method is designed for the detection and quantification of additives in food safety by engineering a nanohybrid (MoS2/SDBS/Cu-CuFe2O4)-based catalysis. Interestingly, the nanohybrid presents peroxidase-like mimetic activity toward the substrate containing 3,3',5,5'-tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2), which are then integrated simply into a detection kit. The blue oxidated TMB in this kit can be converted completely to colorless by some bio-molecule additives in commercial food, such as glutathione (GSH), cysteine (Cys), and ascorbic acid (AA). Remarkably, this process takes just less than 2 min and the detection limits are 2.8 nM, 5.5 nM and 47 nM, respectively. These results show excellent repeatability with a statistical analysis with (*P < 0.05) over 30 tests. Next, the images of the color changes can be captured clearly using a smartphone by red-green-blue (RGB) channels, which provides an opportunity for the development of field-operation device. Additionally, our approach is applied to some targets-indicative foods, showing a recovery range between 95.8 % and 104.2 %, offering an attractive and promising pathway for future practical food safety inspection applications. More importantly, this method can easily be extended to the detection of reducing substances in other analytical fields.
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Aditivos Alimentarios , Límite de Detección , Catálisis , Aditivos Alimentarios/análisis , Bencidinas/química , Molibdeno/química , Peróxido de Hidrógeno/análisis , Peróxido de Hidrógeno/química , Cobre/análisis , Cobre/química , Nanopartículas del Metal/química , Colorimetría/métodosRESUMEN
Interaction between transcription factors (TFs) and motifs is essential for gene regulation and the subsequent phenotype formation. Soybean (Glycine max) JAGGEED 1 (GmJAG1) is a key TF that controls leaf shape, seed number and flower size. To understand the GmJAG1 binding motifs, in this study, we performed the GmJAG1 DNA affinity purification sequencing (DAP-seq) experiment, which is a powerful tool for the de novo motif prediction method. Two new significant GmJAG1 binding motifs were predicted and the EMSA experiments further verified the ability of GmJAG1 bound to these motifs. The potential binding sites in the downstream gene promoter were identified through motif scanning and a potential regulatory network mediated by GmJAG1 was constructed. These results served as important genomic resources for further understanding the regulatory mechanism of GmJAG1.