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1.
medRxiv ; 2024 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-39211861

RESUMEN

Fidelity of wound healing after myocardial infarction (MI) is an important determinant of subsequent adverse cardiac remodeling and failure. Macrophages derived from infiltrating Ly6C hi blood monocytes are a key component of this healing response; however, the importance of other macrophage populations is unclear. Here, using a variety of in vivo murine models and orthogonal approaches, including surgical myocardial infarction, splenectomy, parabiosis, cell adoptive transfer, lineage tracing and cell tracking, RNA sequencing, and functional characterization, we establish in mice an essential role for splenic CD169 + Tim4 + marginal metallophilic macrophages (MMMs) in post-MI wound healing. Splenic CD169 + Tim4 + MMMs circulate in blood as Ly6C low cells expressing macrophage markers and help populate CD169 + Tim4 + CCR2 - LYVE1 low macrophages in the naïve heart. After acute MI, splenic MMMs augment phagocytosis, CCR3 and CCR4 expression, and robustly mobilize to the heart, resulting in marked expansion of cardiac CD169 + Tim4 + LyVE1 low macrophages with an immunomodulatory and pro-resolving gene signature. These macrophages are obligatory for apoptotic neutrophil clearance, suppression of inflammation, and induction of a reparative macrophage phenotype in the infarcted heart. Splenic MMMs are both necessary and sufficient for post-MI wound healing, and limit late pathological remodeling. Liver X receptor-α agonist-induced expansion of the splenic marginal zone and MMMs during acute MI alleviates inflammation and improves short- and long-term cardiac remodeling. Finally, humans with acute ST-elevation MI also exhibit expansion of circulating CD169 + Tim4 + macrophages. We conclude that splenic CD169 + Tim4 + MMMs are required for pro-resolving and reparative responses after MI and can be manipulated for therapeutic benefit to limit long-term heart failure. CLINICAL PERSPECTIVE: What is new?: We establish for the first time that metallophilic marginal macrophages (MMMs) from the spleen, expressing the markers CD169 and Tim4, circulate in blood and traffic to the heart to help maintain the CD169 + Tim4 + CCR2 - LYVE1 low macrophage population in the heart. After acute myocardial infarction, splenic MMMs augment cardiac trafficking in response to chemotactic signals, resulting in expansion of CD169 + Tim4 + macrophages in the heart that play an essential role in post-MI efferocytosis, wound healing and repair while limiting longer term adverse cardiac remodeling. Analogous to mice, humans also exhibit circulating CD169 + Tim4 + macrophages in the blood that expand after acute ST segment elevation MI. What are the clinical implications?: This study highlights the importance of the cardiosplenic axis in acute MI, and the splenic marginal zone, in determining the course and outcome of post-MI LV remodeling.Pharmacological expansion of splenic marginal zone macrophages alleviated post-MI adverse LV remodeling and inflammation, suggesting that splenic modulation is a potential translational therapeutic approach for limiting post-MI inflammation and improving heart repair.

2.
Food Funct ; 15(13): 6914-6928, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38855842

RESUMEN

Pomegranate peel is the by-product of pomegranate processing, which contains a lot of triterpene compounds. In this study, the total triterpenes of pomegranate peel (TPP) were extracted using an ultrasonic-assisted ethanol extraction method under optimal conditions, purified using D-101 macroporous resin to obtain a purity of 75.28%. The triterpenes in TPP were mainly pentacyclic triterpenes determined by LC-MS/MS. Network pharmacological analysis predicted that the anticancer targets were closely related to the MAPK pathway. The in vitro results showed that TPP could inhibit cell proliferation, promote apoptosis, reduce mitochondrial membrane potential and increase ROS levels. The western blot results indicated that the expression levels of the apoptotic proteins Bax, Bcl-2, cytochrome C, cleaved caspase-3 and cleaved caspase-9 were increased. In addition, the protein expression of the MAPK pathway predicted by network pharmacology also changed significantly. These results provided that TPP has potential for adjuvant therapy of tumors.


Asunto(s)
Apoptosis , Proliferación Celular , Extractos Vegetales , Granada (Fruta) , Triterpenos , Triterpenos/farmacología , Triterpenos/química , Triterpenos/aislamiento & purificación , Humanos , Granada (Fruta)/química , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Extractos Vegetales/farmacología , Extractos Vegetales/química , Línea Celular Tumoral , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Frutas/química , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos Fitogénicos/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Especies Reactivas de Oxígeno/metabolismo , Espectrometría de Masas en Tándem
3.
BMC Genomics ; 25(1): 546, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38824587

RESUMEN

BACKGROUND: Purple flowering stalk (Brassica rapa var. purpuraria) is a widely cultivated plant with high nutritional and medicinal value and exhibiting strong adaptability during growing. Mitochondrial (mt) play important role in plant cells for energy production, developing with an independent genetic system. Therefore, it is meaningful to assemble and annotate the functions for the mt genome of plants independently. Though there have been several reports referring the mt genome of in Brassica species, the genome of mt in B. rapa var. purpuraria and its functional gene variations when compared to its closely related species has not yet been addressed. RESULTS: The mt genome of B. rapa var. purpuraria was assembled through the Illumina and Nanopore sequencing platforms, which revealed a length of 219,775 bp with a typical circular structure. The base composition of the whole B. rapa var. purpuraria mt genome revealed A (27.45%), T (27.31%), C (22.91%), and G (22.32%). 59 functional genes, composing of 33 protein-coding genes (PCGs), 23 tRNA genes, and 3 rRNA genes, were annotated. The sequence repeats, codon usage, RNA editing, nucleotide diversity and gene transfer between the cp genome and mt genome were examined in the B. rapa var. purpuraria mt genome. Phylogenetic analysis show that B. rapa var. Purpuraria was closely related to B. rapa subsp. Oleifera and B. juncea. Ka/Ks analysis reflected that most of the PCGs in the B. rapa var. Purpuraria were negatively selected, illustrating that those mt genes were conserved during evolution. CONCLUSIONS: The results of our findings provide valuable information on the B.rapa var. Purpuraria genome, which might facilitate molecular breeding, genetic variation and evolutionary researches for Brassica species in the future.


Asunto(s)
Brassica rapa , Genoma Mitocondrial , Filogenia , Brassica rapa/genética , Anotación de Secuencia Molecular , Genoma de Planta , ARN de Transferencia/genética , Composición de Base
4.
Genomics ; 116(3): 110859, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38750703

RESUMEN

Mitochondria play an important role in the energy production of plant cells through independent genetic systems. This study has aimed to assemble and annotate the functions of the mitochondrial (mt) genome of Luffa cylindrica. The mt genome of L. cylindrica contained two chromosomes with lengths of 380,879 bp and 67,982 bp, respectively. Seventy-seven genes including 39 protein-coding genes, 34 tRNA genes, 3 rRNA genes, and 1 pseudogene, were identified. About 90.63% of the codons ended with A or U bases, and 98.63% of monomers contained A/T, which contributed to the high A/T content (55.91%) of the complete mt genome. Six genes (ATP8, CCMFC, NAD4, RPL10, RPL5 and RPS4) showed positive selection. Phylogenetic analysis indicates that L. cylindrica is closely related to L. acutangula. The present results provide the mt genome of L. cylindrica, which may facilitate possible genetic variation, evolutionary, and molecular breeding studies of L. cylindrica.


Asunto(s)
Genoma Mitocondrial , Luffa , Filogenia , Luffa/genética , ARN de Transferencia/genética , Genoma de Planta , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
6.
Nat Commun ; 14(1): 4184, 2023 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-37443127

RESUMEN

Risk management for drinking water often requires continuous monitoring of various toxins in flowing water. While they can be readily integrated with existing water infrastructure, two-dimensional (2D) electronic sensors often suffer from device-to-device variations due to the lack of an effective strategy for identifying faulty devices from preselected uniform devices based on electronic properties alone, resulting in sensor inaccuracy and thus slowing down their real-world applications. Here, we report the combination of wet transfer, impedance and noise measurements, and machine learning to facilitate the scalable nanofabrication of graphene-based field-effect transistor (GFET) sensor arrays and the efficient identification of faulty devices. Our sensors were able to perform real-time detection of heavy-metal ions (lead and mercury) and E. coli bacteria simultaneously in flowing tap water. This study offers a reliable quality control protocol to increase the potential of electronic sensors for monitoring pollutants in flowing water.


Asunto(s)
Agua Potable , Grafito , Mercurio , Metales Pesados , Contaminantes del Agua , Grafito/química , Escherichia coli , Agua Potable/análisis
7.
J Appl Genet ; 64(3): 419-429, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37380816

RESUMEN

The chloroplast (cp) genome holds immense potential for a variety of applications including species identification, phylogenetic analysis, and evolutionary studies. In this study, we utilized Illumina NovaSeq 6000 to sequence the DNA of Camellia sinensis L. cultivar 'Zhuyeqi', followed by the assembly of its chloroplast genome using SPAdes v3.10.1, with subsequent analysis of its features and phylogenetic placement. The results showed that the cp genome of 'Zhuyeqi' was 157,072 bp, with a large single-copy region (LSC, 86,628 bp), a small single-copy region (SSC,18,282 bp), and two inverted repeat regions (IR, 26,081 bp). The total AT and GC contents of the cp genome of 'Zhuyeqi' were observed to be 62.21% and 37.29%, respectively. The cp genome encoded 135 unique genes, including 90 protein-coding genes (CDS), 37 tRNA genes, and 8 rRNA genes. Moreover, 31 codons and 247 simple sequence repeats (SSRs) were identified. The cp genomes of 'Zhuyeqi' were found to be relatively conserved, with conservation observed in the IR region, which showed no evidence of inversions or rearrangements. The five regions with the largest variations were identified, with four regions (rps12, rps19, rps16, and rpl33) located in the LSC region and one divergent region (trnI-GAU) in the IR region. Phylogenetic analysis revealed that Camellia sinensis (KJ996106.1) was closely related to 'Zhuyeqi', indicating a close phylogenetic relationship between these two species. These findings could provide important genetic information for further research into breeding of tea tree, phylogeny, and evolution of Camellia sinensis.


Asunto(s)
Camellia sinensis , Genoma del Cloroplasto , Filogenia , Camellia sinensis/genética , Evolución Molecular , Fitomejoramiento
8.
JACC Basic Transl Sci ; 7(5): 465-483, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35663630

RESUMEN

Heart failure (HF) is characterized by progressive fibrosis. Both fibroblasts and mesenchymal stem cells (MSCs) can differentiate into pro-fibrotic myofibroblasts. MSCs secrete and express platelet-derived growth factor (PDGF) and its receptors. We hypothesized that PDGF signaling in cardiac MSCs (cMSCs) promotes their myofibroblast differentiation and aggravates post-myocardial infarction left ventricular remodeling and fibrosis. We show that cMSCs from failing hearts post-myocardial infarction exhibit an altered phenotype. Inhibition of PDGF signaling in vitro inhibited cMSC-myofibroblast differentiation, whereas in vivo inhibition during established ischemic HF alleviated left ventricular remodeling and function, and decreased myocardial fibrosis, hypertrophy, and inflammation. Modulating cMSC PDGF receptor expression may thus represent a novel approach to limit pathologic cardiac fibrosis in HF.

9.
BMC Microbiol ; 20(1): 169, 2020 06 17.
Artículo en Inglés | MEDLINE | ID: mdl-32552686

RESUMEN

BACKGROUND: Dietary intervention has been reported to improve intestinal health. The intestinal microbiota of newborn animals plays a fundamental role in the development of intestinal function and the innate immune system. However, little is currently known about dietary interventions in the gut microbiota and barrier function of livestock, especially suckling Bamei piglets. To this end, we studied the effect of early dietary supplementation on intestinal bacterial communities and intestinal barrier function in piglets. RESULTS: 10 purebred Bamei sows were randomly allocated into two groups. In group one, the piglets received a supplementary milk replacer on day 7 of age, whereas the other control group was allowed sow's milk alone. At 21 days, 18 and 17, respectively, piglets in each group of average weight were randomly selected and sacrificed. Tissue and digesta samples were collected from the jejunum to evaluate differences in the microbiome-metabolome and the mRNA expression of inflammatory cytokines (TLR4, TNFα and IL-8) and barrier proteins (ZO-1, Occludin and Claudin-1). Sequencing of 16S rRNA revealed that ES improved the gut microbiome composition of Bamei suckling piglets. The relative abundances of some bacterial species such as Lactobacillales, Romboutsia, Actinobacillus, Bacteroides were significantly reduced in the ES group. Metabolomics analysis indicated that 23 compounds were enriched and 35 compounds decreased in the ES group. And correlation analysis demonstrated that some gut bacterial genera were highly correlated with altered gut microbiota-related metabolites. Meanwhile, ES of Bamei suckling piglets altered the gene expression of inflammatory cytokine and barrier protein in the jejunum. CONCLUSIONS: In summary, these results provide important insights on the relationships between jejunal microbiota and related metabolites, and jejunal barrier function during the early life of Bamei suckling piglets.


Asunto(s)
Bacterias/clasificación , Citocinas/genética , Yeyuno/microbiología , Metabolómica/métodos , Análisis de Secuencia de ADN/métodos , Alimentación Animal , Animales , Animales Recién Nacidos , Bacterias/genética , Bacterias/aislamiento & purificación , Cromatografía Liquida , Suplementos Dietéticos , Regulación de la Expresión Génica , Inmunidad Innata , Yeyuno/inmunología , Espectrometría de Masas , ARN Ribosómico 16S/genética , Distribución Aleatoria , Porcinos
10.
Nanoscale ; 12(3): 1500-1512, 2020 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-31859311

RESUMEN

Atomically thin black phosphorus (BP) field-effect transistors have excellent potential for sensing applications. However, commercial scaling of PFET sensors is still in the early stage due to various technical challenges, such as tedious fabrication, low response% caused by rapid oxidation, non-ideal response output (spike/bidirectional), and large device variation due to poor control over layer thickness among devices. Attempts have been made to address these issues. First, a theoretical model for response% dependence on the number of layers is developed to show the role of atomically thin BP for better responses. A position-tracked, selected-area-exfoliation method has been developed to rapidly produce thin BP layers with a narrow distribution (∼1-7 layers), which can harness excellent gate control over the PFET channel. The typical current on/off ratio is in the range of ∼300-500. The cysteine-modified Al2O3-gated PFET sensors show high responses (∼30-900%) toward a wide detection range (∼1-400 ppb) of lead ions in water with a typical response time of ∼10-30 s. A strategy to minimize device variation is proposed by correlating PFETs' on/off ratio with sensitivity parameters. The thickness variation of the gate oxide is investigated to explain non-ideal and ideal response transient kinetics.

11.
Animals (Basel) ; 9(10)2019 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-31547553

RESUMEN

The jejunum is the primary organ for digestion and nutrient absorption in mammals. The development of the jejunum in suckling piglets directly affects their growth performance post-weaning. The jejunum microbiome plays an important role in proliferation, metabolism, apoptosis, immune, and homeostasis of the epithelial cells within the organ. The composition and diversity of the gut microbiome is susceptible to the protein composition of the diet. Therefore, the effects of maternal low-protein diets on piglets' intestinal microbial structure and function have become a hot topic of study. Herein, a maternal low-protein diet was formulated to explore the effects on jejunum microbiome composition and metabolic profiles in Bamei suckling piglets. Using 16S ribosomal RNA (16S rRNA) sequencing in conjunction with bioinformatics analysis, 21 phyla and 297 genera were identified within the gut microflora. The top 10 phyla and 10 genera are within the gut bacteria. Next, KEGG analysis showed that the low-protein diet significantly increased the gut microbial composition, transport and catabolism, immune system, global and overview maps, amino acid metabolism, metabolism of cofactors and vitamins, endocrine system, biosynthesis of other secondary metabolites, signal transduction, environmental adaptation, and cell motility. Taken together, low-protein diets do not appear to affect the reproductive performance of Bamei sows but improved the gut microbiome of the suckling piglets as well as reduced the probability of diarrhea. The data presented here provide new insights on the dietary protein requirements to support the Huzhu Bamei pig industry.

13.
Circulation ; 139(2): 206-221, 2019 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-30586716

RESUMEN

BACKGROUND: Heart failure (HF) is a state of inappropriately sustained inflammation, suggesting the loss of normal immunosuppressive mechanisms. Regulatory T-lymphocytes (Tregs) are considered key suppressors of immune responses; however, their role in HF is unknown. We hypothesized that Tregs are dysfunctional in ischemic cardiomyopathy and HF, and they promote immune activation and left ventricular (LV) remodeling. METHODS: Adult male wild-type C57BL/6 mice, Foxp3-diphtheria toxin receptor transgenic mice, and tumor necrosis factor (TNF) α receptor-1 (TNFR1)-/- mice underwent nonreperfused myocardial infarction to induce HF or sham operation. LV remodeling was assessed by echocardiography as well as histological and molecular phenotyping. Alterations in Treg profile and function were examined by flow cytometry, immunostaining, and in vitro cell assays. RESULTS: Compared with wild-type sham mice, CD4+Foxp3+ Tregs in wild-type HF mice robustly expanded in the heart, circulation, spleen, and lymph nodes in a phasic manner after myocardial infarction, beyond the early phase of wound healing, and exhibited proinflammatory T helper 1-type features with interferon-γ, TNFα, and TNFR1 expression, loss of immunomodulatory capacity, heightened proliferation, and potentiated antiangiogenic and profibrotic properties. Selective Treg ablation in Foxp3-diphtheria toxin receptor mice with ischemic cardiomyopathy reversed LV remodeling and dysfunction, alleviating hypertrophy and fibrosis, while suppressing circulating CD4+ T cells and systemic inflammation and enhancing tissue neovascularization. Tregs reconstituted after ablation exhibited restoration of immunosuppressive capacity and normalized TNFR1 expression. Treg dysfunction was also tightly coupled to Treg-endothelial cell contact- and TNFR1-dependent inhibition of angiogenesis and the mobilization and tissue infiltration of CD34+Flk1+ circulating angiogenic cells in a C-C chemokine ligand 5/C-C chemokine receptor 5-dependent manner. Anti-CD25-mediated Treg depletion in wild-type mice imparted similar benefits on LV remodeling, circulating angiogenic cells, and tissue neovascularization. CONCLUSIONS: Proinflammatory and antiangiogenic Tregs play an essential pathogenetic role in chronic ischemic HF to promote immune activation and pathological LV remodeling. The restoration of normal Treg function may be a viable approach to therapeutic immunomodulation in this disease.


Asunto(s)
Cardiomiopatías/inmunología , Mediadores de Inflamación/inmunología , Infarto del Miocardio/inmunología , Linfocitos T Reguladores/inmunología , Función Ventricular Izquierda , Remodelación Ventricular , Proteínas Angiogénicas/metabolismo , Animales , Cardiomiopatías/metabolismo , Cardiomiopatías/patología , Cardiomiopatías/fisiopatología , Células Cultivadas , Técnicas de Cocultivo , Modelos Animales de Enfermedad , Células Endoteliales/inmunología , Células Endoteliales/metabolismo , Fibrosis , Mediadores de Inflamación/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Miocardio/inmunología , Miocardio/metabolismo , Miocardio/patología , Neovascularización Fisiológica , Fenotipo , Receptores Tipo I de Factores de Necrosis Tumoral/genética , Receptores Tipo I de Factores de Necrosis Tumoral/metabolismo , Transducción de Señal , Linfocitos T Reguladores/metabolismo
14.
Anal Chem ; 90(24): 14230-14238, 2018 12 18.
Artículo en Inglés | MEDLINE | ID: mdl-30398847

RESUMEN

Recent outbreaks of Ebola-virus infections in several countries demand a rapid point-of-care (POC)-detection strategy. This paper reports on an innovative pathway founded on electronic-resonance-frequency modulation to detect Ebola glycoprotein (GP), on the basis of a carrier-injection-trapping-release-transfer mechanism and the standard antibody-antigen-interaction principle within a dielectric-gated reduced graphene oxide (rGO) field-effect transistor (GFET). The sensitivity of Ebola detection can be significantly enhanced by monitoring the device's electronic-resonance frequency, such as its inflection frequency ( fi), where the phase angle reaches a maximum (θmax). In addition to excellent selectivity, a sensitivity of ∼36-160% and ∼17-40% for 0.001-3.401 mg/L Ebola GP can be achieved at high and low inflection-resonance frequencies, respectively, which are several orders of magnitude higher than the sensitivity from other electronic parameters (e.g., resistance-based sensitivity). Using equivalent circuit modeling for contributions from channel and contact, analytical equations for resonance shifts have been generalized. When matching with the incoming ac-measurement signal, electronic resonance from the phase-angle spectrum evolves from various relaxation processes (e.g., trap and release of injected charges at surface-trap sites of the channel-gate oxide and channel-source or drain interfaces) that are associated with a characteristic emission frequency. Using charge-relaxation dynamics, a high-performance bio-FET sensing platform for healthcare and bioelectronic applications is realized through resonance shifting.


Asunto(s)
Ebolavirus/metabolismo , Grafito/química , Sistemas de Atención de Punto , Transistores Electrónicos , Proteínas Virales/inmunología , Anticuerpos Inmovilizados/química , Anticuerpos Inmovilizados/inmunología , Anticuerpos Antivirales/química , Anticuerpos Antivirales/inmunología , Reacciones Antígeno-Anticuerpo , Oro/química , Fiebre Hemorrágica Ebola/diagnóstico , Humanos , Nanopartículas del Metal/química , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/aislamiento & purificación , Resonancia por Plasmón de Superficie , Proteínas Virales/genética , Proteínas Virales/metabolismo
15.
ACS Appl Mater Interfaces ; 10(31): 26170-26177, 2018 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-29995381

RESUMEN

Benefiting from the reversible conversion reaction upon delithiation, nanosized SnO2, with its theoretical capacity of 1494 mA h g-1, has gained special attention as a promising anode material. Here, we report a self-assembled SnO2/Sn-reduced graphene oxide (rGO) sandwich nanocomposite developed by organometallic precursor coating and in situ transformation. Ultrafine SnO2 nanoparticles with an average diameter of 5 nm are sandwiched within the rGO/carbonaceous network, which not only greatly alleviates the volume changes upon lithiation and aggregation of SnO2 nanoparticles but also facilitates the charge transfer and reaction kinetics of SnO2 upon lithiation/delithiation. As a result, the SnO2/Sn-rGO nanocomposite exhibited a superior lithium storage capacity with a reversible capacity of 1307 mA h g-1 at a current density of 80 mA g-1 in the potential window of 0.01-2.5 V versus Li+/Li and showed a reversible capacity of 767 mA h g-1 over 200 cycles at a current density of 400 mA g-1. When cycling at a higher current density of 1600 mA g-1, the SnO2/Sn-rGO nanocomposite showed a highly stable capacity of 449 mA g-1 without obvious decay after 400 cycles.

16.
Nanotechnology ; 29(37): 375501, 2018 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-29974868

RESUMEN

Stimuli-responsive field-effect transistors (FETs) based on 2D nanomaterials have been considered as attractive candidates for sensing applications due to their rapid response, high sensitivity, and real-time monitoring capabilities. Here we report on an impedance spectroscopy technique for FET sensor applications with ultra-high sensitivity and good reproducibility. An alumina-gated FET, using an ultra-thin black phosphorus flake as the channel material, shows significantly improved stability and ultra-high sensitivity to lead ions in water. In addition, the phase angle in the low frequency region was found to change significantly in the presence of lead ion solutions, whereas it was almost unchanged in the high frequency region. The dominant sensing performance was found at low frequency phase spectrum around 50 Hz and a systematic change in the phase angle in different lead ion concentrations was found. Applying the impedance spectroscopy technique to insulator-gated FET sensors could open a new avenue for real-world sensor applications.

17.
Biosens Bioelectron ; 110: 16-22, 2018 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-29579645

RESUMEN

Contamination of surface and drinking water due to the presence of Escherichia coli bacteria is a major cause of water-borne disease outbreak. To address unmet challenges for practical pathogen detection in contaminated samples, we report fabrication of thermally reduced graphene oxide-based field-effect transistor (rGO FET) passivated with an ultrathin layer of Al2O3 for real-time detection of E. coli bacteria. The sensor could detect a single E. coli cell within 50 s in a 1 µL sample volume. The ultrathin layer of Al2O3 acted as a barrier between rGO and potential interferents present in the sample. E. coli specific antibodies anchored on gold nanoparticles acted as probes for selective capture of E. coli. The high density of negative charge on the surface of E. coli cells strongly modulates the concentration of majority charge carriers in the rGO monolayer, thereby allowing real-time monitoring of E. coli concentration in a given sample. With a low detection limit of single cell, the FET sensor had a linear range of 1-100 CFU in 1 µL volume of sample (i.e., 103 to 105 CFU/ mL). The biosensor with good selectivity and rapid detection was further successfully demonstrated for E. coli sensing in river water. The rGO-based FET sensor provides a low cost and label-free approach, and can be mass produced for detection of a broad spectrum of pathogens in water or other liquid media.


Asunto(s)
Técnicas Biosensibles/instrumentación , Infecciones por Escherichia coli/microbiología , Escherichia coli/aislamiento & purificación , Grafito/química , Ríos/microbiología , Transistores Electrónicos , Técnicas Biosensibles/economía , Diseño de Equipo , Humanos , Límite de Detección , Óxidos/química , Factores de Tiempo
18.
ACS Sens ; 2(11): 1653-1661, 2017 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-29087190

RESUMEN

Rapid and real-time detection of heavy metals in water with a portable microsystem is a growing demand in the field of environmental monitoring, food safety, and future cyber-physical infrastructure. Here, we report a novel ultrasensitive pulse-driven capacitance-based lead ion sensor using self-assembled graphene oxide (GO) monolayer deposition strategy to recognize the heavy metal ions in water. The overall field-effect transistor (FET) structure consists of a thermally reduced graphene oxide (rGO) channel with a thin layer of Al2O3 passivation as a top gate combined with sputtered gold nanoparticles that link with the glutathione (GSH) probe to attract Pb2+ ions in water. Using a preprogrammed microcontroller, chemo-capacitance based detection of lead ions has been demonstrated with this FET sensor. With a rapid response (∼1-2 s) and negligible signal drift, a limit of detection (LOD) < 1 ppb and excellent selectivity (with a sensitivity to lead ions 1 order of magnitude higher than that of interfering ions) can be achieved for Pb2+ measurements. The overall assay time (∼10 s) for background water stabilization followed by lead ion testing and calculation is much shorter than common FET resistance/current measurements (∼minutes) and other conventional methods, such as optical and inductively coupled plasma methods (∼hours). An approximate linear operational range (5-20 ppb) around 15 ppb (the maximum contaminant limit by US Environmental Protection Agency (EPA) for lead in drinking water) makes it especially suitable for drinking water quality monitoring. The validity of the pulse method is confirmed by quantifying Pb2+ in various real water samples such as tap, lake, and river water with an accuracy ∼75%. This capacitance measurement strategy is promising and can be readily extended to various FET-based sensor devices for other targets.


Asunto(s)
Técnicas Biosensibles/instrumentación , Capacidad Eléctrica , Grafito/química , Plomo/análisis , Óxidos/química , Transistores Electrónicos , Calidad del Agua , Glutatión/química , Límite de Detección , Oxidación-Reducción , Temperatura , Factores de Tiempo , Contaminantes Químicos del Agua/análisis
19.
Sci Rep ; 7(1): 10974, 2017 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-28887479

RESUMEN

The Ebola virus transmits a highly contagious, frequently fatal human disease for which there is no specific antiviral treatment. Therefore, rapid, accurate, and early diagnosis of Ebola virus disease (EVD) is critical to public health containment efforts, particularly in developing countries where resources are few and EVD is endemic. We have developed a reduced graphene oxide-based field-effect transistor method for real-time detection of the Ebola virus antigen. This method uses the attractive semiconductor characteristics of graphene-based material, and instantaneously yields highly sensitive and specific detection of Ebola glycoprotein. The feasibility of this method for clinical application in point-of-care technology is evaluated using Ebola glycoprotein suspended in diluted PBS buffer, human serum, and plasma. These results demonstrate the successful fabrication of a promising field-effect transistor biosensor for EVD diagnosis.


Asunto(s)
Antígenos Virales , Técnicas Biosensibles , Ebolavirus , Fiebre Hemorrágica Ebola/diagnóstico , Transistores Electrónicos , Antígenos Virales/inmunología , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Ebolavirus/inmunología , Diseño de Equipo , Fiebre Hemorrágica Ebola/inmunología , Humanos , Sistemas de Atención de Punto , Sensibilidad y Especificidad
20.
Toxicon ; 115: 63-9, 2016 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-26995209

RESUMEN

Araneus ventricosus spider venom, which was collected by electrical stimulation, is abundant in peptides and proteins with molecular weights ranging from 2 kDa to 70 kDa as determined by gel electrophoresis and mass spectrometry. Electrophysiological experiments showed that 50 µg/mL venom could block the voltage-gated sodium channels (VGSCs) currents of the dorsal unpaired median (DUM) neurons of Periplaneta americana cockroaches. However, 500 µg/mL venom could not block the VGSCs currents in rat dorsal root ganglion cells or the neuromuscular transmission in isolated mouse phrenic nerve-hemidiaphragm. Moreover, we also observed that injection of the venom in P. americana gave rise to obvious envenomation symptoms, with a LD50 value of 30.7 µg/g. Enzymatic analysis indicated that the venom possessed activities of several kinds of hydrolases including hyaluronidase and proteases. These results demonstrate that A. ventricosus venom contains bioactive components targeting insects, which are the natural prey of these spiders. Furthermore, the venom was found to be not active in vertebrate. Thus, we suggest that A. ventricosus venom contains novel insect-selective compounds that might be helpful in developing new and safe insecticides.


Asunto(s)
Insecticidas/farmacología , Periplaneta/efectos de los fármacos , Venenos de Araña/farmacología , Arañas , Vertebrados , Animales , Diafragma/efectos de los fármacos , Estimulación Eléctrica , Femenino , Ganglios Espinales/citología , Ganglios Espinales/efectos de los fármacos , Ratones , Peso Molecular , Neuronas/efectos de los fármacos , Nervio Frénico/efectos de los fármacos , Ratas , Transmisión Sináptica/efectos de los fármacos , Pruebas de Toxicidad , Canales de Sodio Activados por Voltaje/efectos de los fármacos
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