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1.
Biosens Bioelectron ; 254: 116218, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38518559

RESUMO

Biodetection for non-invasive diagnostics of fluids, especially urine, remains a challenge to scientists due to low target concentrations. And biological complexes of the detection target may contain contaminants that also interfere with any assay. Dengue non-structural 1 protein (Dengue NS1) is an important biomarker for dengue hemorrhagic fever and dengue shock syndrome. Here, we developed an Au-decorated nanowire platform and applied it with a sandwich fluorophore-linked immunosorbent well plate assay (FLISA) to detect Dengue NS1 in urine. For the platform, we fabricated zinc oxide (ZnO) nanowires to provide a high surface area and then coated them with gold nanoparticles (ZnO/Au nanowires) to simply modify the Dengue NS1 antibody and enhance the fluorescence intensity. Our platform employs a sandwich FLISA that exhibits high sensitivity, specifically detecting Dengue NS1 with a limit of detection (LOD) of 1.35 pg/mL. This LOD was 4500-fold lower than the LOD of a commercially available kit for Dengue NS1 enzyme-linked immunosorbent assay. We believe that our ZnO/Au nanowire platform has the potential to revolutionize the field of non-invasive diagnostics for dengue.


Assuntos
Técnicas Biossensoriais , Vírus da Dengue , Dengue , Nanopartículas Metálicas , Nanofios , Óxido de Zinco , Humanos , Dengue/diagnóstico , Ouro , Sensibilidade e Especificidade , Proteínas não Estruturais Virais , Antígenos Virais , Ensaio de Imunoadsorção Enzimática , Imunoadsorventes , Anticorpos Antivirais
2.
BMC Emerg Med ; 24(1): 5, 2024 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-38185623

RESUMO

BACKGROUND: During disasters (including epidemics such as coronavirus disease 2019), the capacity of emergency departments is exceeded, thereby hindering the administration of appropriate lifesaving measures. Furthermore, the number of overdose patients increases because of the stress overload during emergency situation. The fact that overdose patients are forced to be transported to medical facilities that do not typically treat them is becoming worrisome. Moreover, there is no definitive score for overdose. This study aimed to create a patient-specific scoring system to assess overdose. METHODS: This was a retrospective single-center study. The evidence-based OD score was evaluated on a scale of 0-15. Further, logistic analysis and receiver operating characteristic (ROC) curve analysis were performed to evaluate the score. RESULTS: Overall, 262 patients (including 118 overdose patients) receiving care at the intensive care unit of Japan's Teikyo University Hospital in 2021 were targeted. Regarding the total OD score, ROC analysis revealed a cutoff of 8 (area under the curve [AUC]: 0.99, 95% confidence interval [CI]: 0.980-0.997, sensitivity: 0.95, specificity: 0.95, p < 0.05), which was considered to indicate an overdose. Of the items evaluated in the OD score, the scenario at the location of the patient's discovery (adjusted odds ratio [AOR]: 16.8, 95% CI: 5.0-255.9, p = 0.002) and recent experience of mental anxiety (AOR: 55.7, 95% CI: 2.8-5399.5, p = 0.03) significantly predicted an overdose in multivariable logistic regression analysis. External validation revealed that the OD score could also identify overdose in patients treated in a cohort from 2022 (average cutoff: 8.6, average AUC: 1.0, p < 0.0001). CONCLUSIONS: The OD score could accurately assess overdose patients. Medical facilities that do not frequently address overdose patients will benefit from the use of this score.


Assuntos
COVID-19 , Overdose de Drogas , Humanos , Estudos Retrospectivos , Overdose de Drogas/diagnóstico , Overdose de Drogas/epidemiologia , Ansiedade , Área Sob a Curva , COVID-19/epidemiologia
3.
Biol Pharm Bull ; 47(1): 112-119, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37967973

RESUMO

Overdose has become a global social problem. The Japanese government requires gatekeeper training to detect and prevent indicators of overdose and suicide. However, knowledge of necessary factors for the gatekeeper of overdose (patient intervention) is limited. This study aimed to investigate the characteristics of individuals who experienced intervening persons expected to overdose, and to identify the factors required of gatekeepers. A Google form was used to survey 298 pharmacists and registered sellers in Japan. We searched for factors by logistic analysis. Knowledge of prescription drugs used for overdose was higher among pharmacists than among registered sellers. Conversely, pharmacists and registered sellers had similar knowledge about OTC drugs. Overall multivariate logistic regression analysis revealed countermeasures against overdose at their workplace (odds ratio (OR): 4.01, 95% confidence interval (CI): 2.25-7.15, p < 0.01) and knowledge that overdose is on the rise (OR: 1.93, 95% CI: 1.04-3.69, p < 0.05) to be significantly associated with intervention experience as a gatekeeper. Countermeasures against overdose at their workplace (OR: 2.40, 95% CI: 1.10-5.25, p < 0.05) in pharmacists and years of work experience (OR: 1.13, 95% CI: 1.04-1.24, p < 0.05), countermeasure against overdose at their workplace (OR: 3.43, 95% CI: 1.18-10.0, p < 0.05), and willingness to participate in study sessions and workshops on overdose (OR: 3.50, 95% CI: 1.51-8.10, p < 0.05) in registered seller were significantly associated with intervention experience as a gatekeeper. These results are useful evidences for countermeasures and gatekeeper training for overdose at pharmacies and drugstores in the community.


Assuntos
Overdose de Drogas , Humanos , Overdose de Drogas/prevenção & controle , Inquéritos e Questionários , Modelos Logísticos , Farmacêuticos , Japão
4.
Nature ; 621(7977): 162-170, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37587342

RESUMO

Certain bacterial strains from the microbiome induce a potent, antigen-specific T cell response1-5. However, the specificity of microbiome-induced T cells has not been explored at the strain level across the gut community. Here, we colonize germ-free mice with complex defined communities (roughly 100 bacterial strains) and profile T cell responses to each strain. The pattern of responses suggests that many T cells in the gut repertoire recognize several bacterial strains from the community. We constructed T cell hybridomas from 92 T cell receptor (TCR) clonotypes; by screening every strain in the community against each hybridoma, we find that nearly all the bacteria-specific TCRs show a one-to-many TCR-to-strain relationship, including 13 abundant TCR clonotypes that each recognize 18 Firmicutes. By screening three pooled bacterial genomic libraries, we discover that these 13 clonotypes share a single target: a conserved substrate-binding protein from an ATP-binding cassette transport system. Peripheral regulatory T cells and T helper 17 cells specific for an epitope from this protein are abundant in community-colonized and specific pathogen-free mice. Our work reveals that T cell recognition of commensals is focused on widely conserved, highly expressed cell-surface antigens, opening the door to new therapeutic strategies in which colonist-specific immune responses are rationally altered or redirected.


Assuntos
Bactérias , Microbioma Gastrointestinal , Linfócitos T , Animais , Camundongos , Antígenos de Superfície/imunologia , Bactérias/classificação , Bactérias/imunologia , Firmicutes/imunologia , Microbioma Gastrointestinal/imunologia , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Linfócitos T/imunologia , Simbiose/imunologia , Vida Livre de Germes , Receptores de Antígenos de Linfócitos T/imunologia , Hibridomas/citologia , Hibridomas/imunologia , Separação Celular
5.
Biol Pharm Bull ; 46(7): 898-906, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37394641

RESUMO

Food-derived peptides have various biological activities. When food proteins are ingested orally, they are digested into peptides by endogenous digestive enzymes and absorbed by the immune cell-rich intestinal tract. However, little is known about the effects of food-derived peptides on the motility of human immune cells. In this study, we aimed to understand the effects of peptides derived from a soybean protein ß-conglycinin on the motility of human peripheral polymorphonuclear leukocytes. We illustrated that MITL and MITLAIPVNKPGR, produced by digestion using in-vivo enzymes (trypsin and pancreatic elastase) of ß-conglycinin, induces the migration of dibutyryl cAMP (Bt2 cAMP)-differentiated human promyelocytic leukemia 60 (HL-60) cells and human polymorphonuclear leukocytes in a dose- and time-dependent manner. This migration was more pronounced in Bt2 cAMP-differentiated HL-60 cells; mRNA expression of formyl peptide receptor (FPR) 1 increased significantly than in all-trans-retinoic acid (ATRA)-differentiated HL-60 cells. This migration was inhibited by tert-butoxycarbonyl (Boc)-MLP, an inhibitor of FPR, and by pretreatment with pertussis toxin (PTX). However, the effect was weak when treated with WRW4, a selective inhibitor of the FPR2. We then demonstrated that MITLAIPVNKPGR induced intracellular calcium responses in human polymorphonuclear leukocytes and Bt2 cAMP-HL60 cells. Furthermore, pre-treatment by fMLP desensitized the calcium response of MITLAIPVNKPGR in these cells. From the above, MITLAIPVNKPGR and MITL derived from soybean ß-conglycinin induced polymorphonuclear leukocyte migration via the FPR1-dependent mechanism. We found chemotactic peptides to human polymorphonuclear leukocytes, which are the endogenous enzyme digests of soybean protein.


Assuntos
Neutrófilos , Proteínas de Soja , Humanos , Neutrófilos/metabolismo , Proteínas de Soja/farmacologia , Proteínas de Soja/metabolismo , Cálcio/metabolismo , Peptídeos/farmacologia
6.
ACS Appl Mater Interfaces ; 15(30): 36866-36876, 2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37486017

RESUMO

A low-temperature Al2O3 deposition process provides a simplified method to form a conductive two-dimensional electron gas (2DEG) at the metal oxide/Al2O3 heterointerface. However, the impact of key factors of the interface defects and cation interdiffusion on the interface is still not well understood. Furthermore, there is still a blank space in terms of applications that go beyond the understanding of the interface's electrical conductivity. In this work, we carried out a systematic experimental study by oxygen plasma pretreatment and thermal annealing post-treatment to study the impact of interface defects and cation interdiffusion at the In2O3/Al2O3 interface on the electrical conductance, respectively. Combining the trends in electrical conductance with the structural characteristics, we found that building a sharp interface with a high concentration of interface defects provides a reliable approach to producing such a conductive interface. After applying this conductive interface as electrodes for fabricating a field-effect transistor (FET) device, we found that this interface electrode exhibited ultrastability in phosphate-buffered saline (PBS), a commonly used biological saline solution. This study provides new insights into the formation of conductive 2DEGs at metal oxide/Al2O3 interfaces and lays the foundation for further applications as electrodes in bioelectronic devices.

7.
Cell ; 186(13): 2839-2852.e21, 2023 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-37352836

RESUMO

The gut microbiome is complex, raising questions about the role of individual strains in the community. Here, we address this question by constructing variants of a complex defined community in which we eliminate strains that occupy the bile acid 7α-dehydroxylation niche. Omitting Clostridium scindens (Cs) and Clostridium hylemonae (Ch) eliminates secondary bile acid production and reshapes the community in a highly specific manner: eight strains change in relative abundance by >100-fold. In single-strain dropout communities, Cs and Ch reach the same relative abundance and dehydroxylate bile acids to a similar extent. However, Clostridium sporogenes increases >1,000-fold in the ΔCs but not ΔCh dropout, reshaping the pool of microbiome-derived phenylalanine metabolites. Thus, strains that are functionally redundant within a niche can have widely varying impacts outside the niche, and a strain swap can ripple through the community in an unpredictable manner, resulting in a large impact on an unrelated community-level phenotype.


Assuntos
Microbioma Gastrointestinal , Ácidos e Sais Biliares , Clostridiales
8.
ACS Appl Mater Interfaces ; 15(19): 23931-23937, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37155349

RESUMO

Atomic layer deposition (ALD) offers excellent controllability of spatial uniformity, film thickness at the Angstrom level, and film composition even for high-aspect-ratio nanostructured surfaces, which are rarely attainable by other conventional deposition methodologies. Although ALD has been successfully applied to various substrates under open-top circumstances, the applicability of ALD to confined spaces has been limited because of the inherent difficulty of supplying precursors into confined spaces. Here, we propose a rational methodology to apply ALD growths to confined spaces (meter-long microtubes with an aspect ratio of up to 10 000). The ALD system, which can generate differential pressures to confined spaces, was newly developed. By using this ALD system, it is possible to deposit TiOx layers onto the inner surface of capillary tubes with a length of 1000 mm and an inner diameter of 100 µm with spatial deposition uniformity. Furthermore, we show the superior thermal and chemical robustness of TiOx-coated capillary microtubes for molecular separations when compared to conventional molecule-coated capillary microtubes. Thus, the present rational strategy of space-confined ALD offers a useful approach to design the chemical and physical properties of the inner surfaces of various confined spaces.

9.
Biosens Bioelectron ; 234: 115318, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37172361

RESUMO

Cell-free DNA (cfDNA) and extracellular vesicles (EVs) are molecular biomarkers in liquid biopsies that can be applied for cancer detection, which are known to carry information on the necessary conditions for oncogenesis and cancer cell-specific activities after oncogenesis, respectively. Analyses for both cfDNA and EVs from the same body fluid can provide insights into screening and identifying the molecular subtypes of cancer; however, a major bottleneck is the lack of efficient and standardized techniques for the isolation of cfDNA and EVs from clinical specimens. Here, we achieved catch-and-release isolation by hydrogen bond-mediated binding of cfDNA in urine to zinc oxide (ZnO) nanowires, which also capture EVs by surface charge, and subsequently we identified genetic mutations in urinary cfDNA. The binding strength of hydrogen bonds between single-crystal ZnO nanowires and DNA was found to be equal to or larger than that of conventional hydrophobic interactions, suggesting the possibility of isolating trace amounts of cfDNA. Our results demonstrated that nanowire-based cancer screening assay can screen cancer and can identify the molecular subtypes of cancer in urine from brain tumor patients through EV analysis and cfDNA mutation analysis. We anticipate our method to be a starting point for more sophisticated diagnostic models of cancer screening and identification.


Assuntos
Técnicas Biossensoriais , Ácidos Nucleicos Livres , Vesículas Extracelulares , Neoplasias , Óxido de Zinco , Humanos , Biópsia Líquida/métodos , Neoplasias/metabolismo , Vesículas Extracelulares/química , Mutação , Carcinogênese/metabolismo , Biomarcadores Tumorais/análise
10.
ACS Appl Mater Interfaces ; 15(22): 27099-27109, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37226988

RESUMO

Artificially programming a sequence of organic-metal oxide multilayers (superlattices) by using atomic layer deposition (ALD) is a fascinating and challenging issue in material chemistry. However, the complex chemical reactions between ALD precursors and organic layer surfaces have limited their applications for various material combinations. Here, we demonstrate the impact of interfacial molecular compatibility on the formation of organic-metal oxide superlattices using ALD. The effects of both organic and inorganic compositions on the metal oxide layer formation processes onto self-assembled monolayers (SAM) were examined by using scanning transmission electron microscopy, in situ quartz crystal microbalance measurements, and Fourier-transformed infrared spectroscopy. These series of experiments reveal that the terminal group of organic SAM molecules must satisfy two conflicting requirements, the first of which is to promptly react with ALD precursors and the second is not to bind strongly to the bottom metal oxide layers to avoid undesired SAM conformations. OH-terminated phosphate aliphatic molecules, which we have synthesized, were identified as one of the best candidates for such a purpose. Molecular compatibility between metal oxide precursors and the -OHs must be properly considered to form superlattices. In addition, it is also important to form densely packed and all-trans-like SAMs to maximize the surface density of reactive -OHs on the SAMs. Based on these design strategies for organic-metal oxide superlattices, we have successfully fabricated various superlattices composed of metal oxides (Al-, Hf-, Mg-, Sn-, Ti-, and Zr oxides) and their multilayered structures.

11.
Science ; 380(6641): 203-210, 2023 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-37053311

RESUMO

Certain bacterial colonists induce a highly specific T cell response. A hallmark of this encounter is that adaptive immunity develops preemptively, in the absence of an infection. However, the functional properties of colonist-induced T cells are not well defined, limiting our ability to understand anticommensal immunity and harness it therapeutically. We addressed both challenges by engineering the skin bacterium Staphylococcus epidermidis to express tumor antigens anchored to secreted or cell-surface proteins. Upon colonization, engineered S. epidermidis elicits tumor-specific T cells that circulate, infiltrate local and metastatic lesions, and exert cytotoxic activity. Thus, the immune response to a skin colonist can promote cellular immunity at a distal site and can be redirected against a target of therapeutic interest by expressing a target-derived antigen in a commensal.


Assuntos
Antígenos de Neoplasias , Melanoma , Neoplasias Cutâneas , Pele , Staphylococcus epidermidis , Humanos , Imunidade Celular , Melanoma/imunologia , Melanoma/terapia , Pele/microbiologia , Engenharia Genética , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/imunologia , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/terapia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia
12.
Nanoscale Adv ; 5(6): 1651-1663, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36926567

RESUMO

GaAs/AlGaAs core-shell nanowires, typically having 250 nm diameter and 6 µm length, were grown on 2-inch Si wafers by the single process of molecular beam epitaxy using constituent Ga-induced self-catalysed vapor-liquid-solid growth. The growth was carried out without specific pre-treatment such as film deposition, patterning, and etching. The outermost Al-rich AlGaAs shells form a native oxide surface protection layer, which provides efficient passivation with elongated carrier lifetime. The 2-inch Si substrate sample exhibits a dark-colored feature due to the light absorption of the nanowires where the reflectance in the visible wavelengths is less than 2%. Homogeneous and optically luminescent and adsorptive GaAs-related core-shell nanowires were prepared over the wafer, showing the prospect for large-volume III-V heterostructure devices available with this approach as complementary device technologies for integration with silicon.

13.
Yakugaku Zasshi ; 143(2): 171-181, 2023.
Artigo em Japonês | MEDLINE | ID: mdl-36724930

RESUMO

In recent years, there has been an urgent need to build a pediatric in-home care system with multiple occupations. This study aims to clarify the role of pharmacists in this system by investigating what visiting nurses' expectation from them. A self-administered questionnaire survey was conducted, targeting nurses enrolled in 10 home-visit nursing facilities. Responses were received from 51 nurses at six facilities, and the questionnaire collection rate was 42.5%. The primary role of the pharmacists that nurses regarded was the management of prescribed oral medications such as "mixing powders, single-dose packages at each time" and "sorting and summarizing each time medicine packages are taken." Other roles included providing information based on the drug's physicochemical properties such as "the tube gets clogged easily when the medicine is administered" and "do not crush the medicine when administering it." The findings of this study are novel because they revealed that pharmacists need to perform pharmaceutical assessments on the influences of changes in children's physical condition and the presence or absence of effects of drugs, and share information in real time. They also need to participate in a conference at discharge. For the first time, this study revealed the roles of pharmacists expected by nurses in pediatric in-home care. However, further knowledge or training are required, especially in terms of the relationship between the symptoms in children and the medicine administered, for pharmacists to effectively practice their roles.


Assuntos
Serviços de Assistência Domiciliar , Enfermeiros de Saúde Comunitária , Humanos , Criança , Farmacêuticos , Inquéritos e Questionários
14.
ACS Nano ; 17(3): 2235-2244, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36655866

RESUMO

Extracellular vesicles (EVs) have promising potential as biomarkers for early cancer diagnosis. The EVs have been widely studied as biological cargo containing essential biological information not only from inside vesicles such as nucleic acids and proteins but also from outside vesicles such as membrane proteins and glycolipids. Although various methods have been developed to isolate EVs with high yields such as captures based on density, size, and immunoaffinity, different measurement systems are needed to analyze EVs after isolation, and a platform that enables all-in-one analysis of EVs from capture to detection in multiple samples is desired. Since a nanowire-based approach has shown an effective capability for capturing EVs via surface charge interaction compared to other conventional methods, here, we upgraded the conventional well plate assay to an all-in-one nanowire-integrated well plate assay system (i.e., a nanowire assay system) that enables charge-based EV capture and EV analysis of membrane proteins. We applied the nanowire assay system to analyze EVs from brain tumor organoids in which tumor environments, including vascular formations, were reconstructed, and we found that the membrane protein expression ratio of CD31/CD63 was 1.42-fold higher in the tumor organoid-derived EVs with a p-value less than 0.05. Furthermore, this ratio for urine samples from glioblastoma patients was 2.25-fold higher than that from noncancer subjects with a p-value less than 0.05 as well. Our results demonstrated that the conventional well plate method integrated with the nanowire-based EV capture approach allows users not only to capture EVs effectively but also to analyze them in one assay system. We anticipate that the all-in-one nanowire assay system will be a powerful tool for elucidating EV-mediated tumor-microenvironment crosstalk.


Assuntos
Neoplasias Encefálicas , Vesículas Extracelulares , Nanofios , Humanos , Vesículas Extracelulares/metabolismo , Biomarcadores/metabolismo , Neoplasias Encefálicas/diagnóstico , Proteínas de Membrana/metabolismo , Microambiente Tumoral
15.
Cell ; 185(19): 3617-3636.e19, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-36070752

RESUMO

Efforts to model the human gut microbiome in mice have led to important insights into the mechanisms of host-microbe interactions. However, the model communities studied to date have been defined or complex, but not both, limiting their utility. Here, we construct and characterize in vitro a defined community of 104 bacterial species composed of the most common taxa from the human gut microbiota (hCom1). We then used an iterative experimental process to fill open niches: germ-free mice were colonized with hCom1 and then challenged with a human fecal sample. We identified new species that engrafted following fecal challenge and added them to hCom1, yielding hCom2. In gnotobiotic mice, hCom2 exhibited increased stability to fecal challenge and robust colonization resistance against pathogenic Escherichia coli. Mice colonized by either hCom2 or a human fecal community are phenotypically similar, suggesting that this consortium will enable a mechanistic interrogation of species and genes on microbiome-associated phenotypes.


Assuntos
Microbioma Gastrointestinal , Microbiota , Animais , Bactérias/genética , Escherichia coli , Fezes , Microbioma Gastrointestinal/genética , Vida Livre de Germes , Humanos , Camundongos
16.
Chem Commun (Camb) ; 58(44): 6377-6380, 2022 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-35593073

RESUMO

Breath odor sensing-based individual authentication was conducted for the first time using an artificial olfactory sensor system. Using a 16-channel chemiresistive sensor array and machine learning, a mean accuracy of >97% was successfully achieved. The impact of the number of sensors on the accuracy and reproducibility was also demonstrated.


Assuntos
Aprendizado de Máquina , Odorantes , Reprodutibilidade dos Testes
17.
Chem Commun (Camb) ; 58(44): 6465, 2022 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-35593413

RESUMO

Correction for 'Breath odor-based individual authentication by an artificial olfactory sensor system and machine learning' by Chaiyanut Jirayupat et al., Chem. Commun., 2022, DOI: https://doi.org/10.1039/D1CC06384G.

18.
ACS Nano ; 16(6): 8630-8640, 2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35471008

RESUMO

Semiconducting nanomaterials with 3D network structures exhibit various fascinating properties such as electrical conduction, high permeability, and large surface areas, which are beneficial for adsorption, separation, and sensing applications. However, research on these materials is substantially restricted by the limited trans-scalability of their structural design and tunability of electrical conductivity. To overcome this challenge, a pyrolyzed cellulose nanofiber paper (CNP) semiconductor with a 3D network structure is proposed. Its nano-micro-macro trans-scale structural design is achieved by a combination of iodine-mediated morphology-retaining pyrolysis with spatially controlled drying of a cellulose nanofiber dispersion and paper-crafting techniques, such as microembossing, origami, and kirigami. The electrical conduction of this semiconductor is widely and systematically tuned, via the temperature-controlled progressive pyrolysis of CNP, from insulating (1012 Ω cm) to quasimetallic (10-2 Ω cm), which considerably exceeds that attained in other previously reported nanomaterials with 3D networks. The pyrolyzed CNP semiconductor provides not only the tailorable functionality for applications ranging from water-vapor-selective sensors to enzymatic biofuel cell electrodes but also the designability of macroscopic device configurations for stretchable and wearable applications. This study provides a pathway to realize structurally and functionally designable semiconducting nanomaterials and all-nanocellulose semiconducting technology for diverse electronics.

19.
Nano Lett ; 22(6): 2569-2577, 2022 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-35226506

RESUMO

In situ fabrication of well-defined bridging nanostructures is an interesting and unique approach to three-dimensionally design nanosensor structures, which are hardly attainable by other methods. Here, we demonstrate the significant effect of edge-topological regulation on in situ fabrication of ZnO bridging nanosensors. When employing seed layers with a sharp edge, which is a well-defined structure in conventional lithography, the bridging angles and electrical resistances between two opposing electrodes were randomly distributed. The stochastic nature of bridging growth direction at the sharp edges inherently causes such unintentional variation of structural and electrical properties. We propose an edgeless seed layer structure using a two-layers resist method to solve the above uncontrollability of bridging nanosensors. Such bridging nanosensors not only substantially improved the uniformity of structural and electrical properties between two opposing electrodes but also significantly enhanced the sensing responses for NO2 with the smaller variance and the lower limit of detection via in situ controlled electrical contacts.


Assuntos
Nanoestruturas , Eletrodos , Nanoestruturas/química
20.
ACS Sens ; 7(2): 534-544, 2022 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-35072452

RESUMO

Humidity and moisture effects, frequently called water poisoning, in surroundings are inevitable for various molecular sensing devices, strongly affecting their sensing characteristics. Here, we demonstrate a water-selective nanostructured dehumidifier composed of ZnO/TiO2/CaCl2 core-shell heterostructured nanowires for molecular sensing spaces. The fabricated nanostructured dehumidifier is highly water-selective without detrimental adsorptions of various volatile organic compound molecules and can be repeatedly operated. The thermally controllable and reversible dehydration process of CaCl2·nH2O thin nanolayers on hydrophilic ZnO/TiO2 nanowire surfaces plays a vital role in such water-selective and repeatable dehumidifying operations. Furthermore, the limitation of detection for sensing acetone and nonanal molecules in the presence of moisture (relative humidity ∼ 90%) was improved more than 20 times using nanocomposite sensors by operating the developed nanostructured dehumidifier. Thus, the proposed water-selective nanostructured dehumidifier offers a rational strategy and platform to overcome water poisoning issues for various molecular and gas sensors.


Assuntos
Nanofios , Óxido de Zinco , Cloreto de Cálcio , Umidade , Água
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