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1.
Small ; 20(26): e2310120, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38279619

RESUMO

Supercapacitors (SCs) with outstanding versatility have a lot of potential applications in next-generation electronics. However, their practical uses are limited by their short working potential window and ultralow-specific capacity. Herein, the facile one-step in-situ hydrothermal synthesis is employed for the construction of a NiMo3S4/BP (black phosphorous) hybrid with a 3D hierarchical structure. After optimization, the NiMo3S4/BP hybrid displays a high specific capacitance of 830 F/g at 1 A/g compared to the pristine NiMo3S4 electrode. The fabricated NiMo3S4/BP//NiCo2S4/Ti3C2Tx asymmetric supercapacitor exhibits a better specific capacitance of 120 F/g at 0.5 A/g, which also demonstrates a high energy density of 54 Wh/kg at 1148.53 W/kg and good cycle stability with capacity retention of 86% and 97% of Coulombic efficiency after 6000 cycles. Further from the DFT simulations, the hybrid NiMo3S4/BP structure shows higher conductivity and quantum capacitance, which demonstrate greater charge storage capability, due to enhanced electronic states near the Fermi level. The lower diffusion energy barrier for the electrolyte K+ ions in the hybrid structure is facilitated by improved charge transfer performance for the hybrid NiMo3S4/BP. This work highlights the potential significance of hybrid nanoarchitectonics and compositional tunability as an emerging method for improving the charge storage capabilities of active electrodes.

2.
Nano Lett ; 22(22): 8860-8866, 2022 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-36346747

RESUMO

Chiral nonlinear metasurfaces could natively synergize nonlinear wavefront manipulation and circular dichroism, offering enhanced capacity for multifunctional and multiplexed nonlinear metasurfaces. However, it is still quite challenging to simultaneously enable strong chiral response, precise wavefront control, high nonlinear conversion efficiency, and independent functions on spins and chirality. Here, we propose and experimentally demonstrate multiplexed third-harmonic (TH) holograms with four channels based on a chiral Au-ZnO hybrid metasurface. Specifically, the left- and right-handed circularly polarized (LCP and RCP) components of the TH holographic images can be designed independently under the excitation of an LCP (or RCP) fundamental beam. In addition, the TH conversion efficiency is measured to be as large as 10-5, which is 8.6 times stronger than that of a bare ZnO film with the same thickness. Thus, our work provides a promising platform for realizing efficient and multifunctional nonlinear nanodevices.


Assuntos
Microscopia de Geração do Segundo Harmônico , Óxido de Zinco , Dicroísmo Circular
3.
Bioprocess Biosyst Eng ; 45(11): 1781-1797, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36125526

RESUMO

Herein, we designed a DNA framework-based intelligent nanorobot using toehold-mediated strand displacement reaction-based molecular programming and logic gate operation for the selective and synchronous detection of miR21 and miR125b, which are known as significant cancer biomarkers. Moreover, to investigate the applicability of our design, DNA nanorobots were implemented as capping agents onto the pores of MSNs. These agents can develop a logic-responsive hybrid nanostructure capable of specific drug release in the presence of both targets. The prosperous synthesis steps were verified by FTIR, XRD, BET, UV-visible, FESEM-EDX mapping, and HRTEM analyses. Finally, the proper release of the drug in the presence of both target microRNAs was studied. This Hybrid DNA Nanostructure was designed with the possibility to respond to any target oligonucleotides with 22 nucleotides length.


Assuntos
MicroRNAs , Nanoestruturas , Neoplasias , Humanos , MicroRNAs/análise , MicroRNAs/genética , Biomarcadores Tumorais/genética , Neoplasias/genética , DNA/química , Nanoestruturas/química
4.
Nano Lett ; 20(6): 4286-4291, 2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32365296

RESUMO

Developing renewable and sustainable energy sources is a compelling goal in materials science and engineering. In particular, natural photosynthesis with its infinite energy reservoir provides profound inspiration for energy conversion and storage systems. Here, we report a multiplex living solar cell that offers a drastic power enhancement by harnessing the broadband spectra of the visible wavelength range for photosynthesis. Cyanobacteria are embedded into a nanostructural complex composed of Au nanoparticles (NPs) and ZnO nanorods (NRs). This nanocomposite system is capable of not only generating excitons but also amplifying the photosynthetic performance of the cell via a far-field scattering effect in the broadband region of the light, resulting in multiplex energy harvesting with a peak power density of 6.15 mW/m2. We envision that this study will provide a strategic way to enhance the performance of biophotovoltaics, enabling efficient and durable energy generation.

5.
Nano Lett ; 18(2): 1344-1350, 2018 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-29370525

RESUMO

Recently, nonlinear hybrid metasurface comes into an attractive new concept in the research of nanophotonics and nanotechnology. It is composed of semiconductors with an intrinsically large nonlinear susceptibility and traditional plasmonic metasurfaces, offering opportunities for efficiently generating and manipulating nonlinear optical responses. A high second-harmonic generation (SHG) conversion efficiency has been demonstrated in the mid-infrared region by using multiquantum-well (MQW)-based plasmonic metasurfaces. However, it has yet to be demonstrated in the visible region. Here, we present a new type of nonlinear hybrid metasurfaces for the visible region, which consists of a single layer of tungsten disulfide (WS2) and a phased gold nanohole array. The results indicate that a large SHG susceptibility of ∼10-1 nm/V at 810 nm is achieved, which is 2-3 orders of magnitude larger than that of typical plasmonic metasurfaces. Nonlinear metalenses with the focal lengths of 30, 50, and 100 µm are demonstrated experimentally, providing a direct evidence for both generating and manipulating SH signals based on the nonlinear hybrid metasurfaces. It shows great potential applications in designing of integrated, ultrathin, compacted, and efficient nonlinear optical devices, such as frequency converters, nonlinear holography, and the generation of nonlinear optical vortex beams.

6.
Mol Pharm ; 15(2): 458-471, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29226684

RESUMO

The increasing importance of sigma-2 receptor as target for the diagnosis and therapy of tumors paves the way for the development of innovative optically traceable fluorescent probes as tumor cell contrast and therapeutic agents. Here, a novel hybrid organic-inorganic nanostructure is developed by combining the superior fluorescent properties of inorganic quantum dots (QDs), coated with a hydrophilic silica shell (QD@SiO2 NPs), the versatility of the silica shell, and the high selectivity for sigma-2 receptor of the two synthetic ligands, namely, the 6-[(6-aminohexyl)oxy]-2-(3-(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)propyl)-3,4-dihydroisoquinolin-1(2H)-one (MLP66) and 6-[1-[3-(4-cyclohexylpiperazin-1-yl)propyl]-1,2,3,4-tetrahydronaphthalen-5-yloxy]hexylamine (TA6). The proposed nanostructures represent a challenging alternative to all previously studied organic small fluorescent molecules, based on the same sigma-2 receptor affinity moieties. Flow cytometry and confocal fluorescence microscopy experiments, respectively, on fixed and living cancerous MCF7 cells, which overexpress the sigma-2 receptor, prove the ability of functionalized (QD@SiO2-TA6 and QD@SiO2-MLP66) NPs to be internalized and demonstrate their affinity to the sigma-2 receptor, ultimately validating the targeting properties conveyed to the NPs by sigma-2 ligand conjugation. The presented QD-based nanoprobes possess a great potential as in vitro selective sigma-2 receptor imaging agent and, consequently, could provide a significant impact to future theranostic applications.


Assuntos
Imagem Molecular/métodos , Neoplasias/diagnóstico por imagem , Pontos Quânticos/química , Receptores sigma/metabolismo , Nanomedicina Teranóstica/métodos , Citometria de Fluxo , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Humanos , Ligantes , Células MCF-7 , Microscopia Confocal , Microscopia de Fluorescência , Sondas Moleculares/química , Sondas Moleculares/metabolismo , Nanoestruturas/química , Neoplasias/patologia , Pontos Quânticos/metabolismo , Dióxido de Silício/química
7.
Methods ; 129: 89-95, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28600228

RESUMO

In this work, we have developed for the first time a method to make novel gold and platinum hybrid bimetallic nanostructures differing in shape and size. Au-Pt nanostructures were prepared by electrodeposition in two simple steps. The first step consists of the electrodeposition of nanocoral Au onto a gold substrate using hydrogen as a dynamic template in an ammonium chloride solution. After that, the Pt nanostructures were deposited onto the nanocoral Au organized in pores. Using Pt (II) and Pt (IV), we realized nanocoral Au decorated with Pt nanospheres and nanocoral Au decorated with Pt nanoflowers, respectively. The bimetallic nanostructures showed better capability to electrochemically oxidize hydrogen peroxide compared with nanocoral Au. Moreover, Au-Pt nanostructures were able to lower the potential of detection and a higher performance was obtained at a low applied potential. Then, glucose oxidase was immobilized onto the bimetallic Au-Pt nanostructure using cross-linking with glutaraldehyde. The biosensor was characterized by chronoamperometry at +0.15V vs. Ag pseudo-reference electrode (PRE) and showed good analytical performances with a linear range from 0.01 to 2.00mM and a sensitivity of 33.66µA/mMcm2. The good value of Kmapp (2.28mM) demonstrates that the hybrid nanostructure is a favorable environment for the enzyme. Moreover, the low working potential can minimize the interference from ascorbic acid and uric acid as well as reducing power consumption to effect sensing. The simple procedure to realize this nanostructure and to immobilize enzymes, as well as the analytical performances of the resulting devices, encourage the use of this technology for the development of biosensors for clinical analysis.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Peróxido de Hidrogênio/isolamento & purificação , Nanoestruturas/química , Glucose/química , Glucose Oxidase/química , Ouro/química , Peróxido de Hidrogênio/química , Platina/química
8.
Mikrochim Acta ; 185(10): 496, 2018 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-30288615

RESUMO

A composite consisting of NiCo2S4 and reduced graphene oxide (rGO) was prepared via a hydrothermal process. Compared to individual NiCo2S4 nanomaterials or reduced graphene oxide, the composite exhibits enhanced oxidase-like activity. It is found that dopamine (DA) inhibits the ability of NiCo2S4-rGO to oxidize the substrate 3,3',5',5'-tetramethylbenzidine (TMB) to form blue colored ox-TMB. Based on these findings, a colorimetric method for determination of DA was worked out. The absorption, best measured at 652 nm, increases linearly in the 0.5-100 µM DA concentration range, and the limit of detection is 0.42 µM. This method was successfully applied to the detection of DA in spiked human serum samples. Graphical abstract A hierarchical NiCo2S4-rGO composite was prepared through two-step hydrothermal process. It exhibits enhanced oxidase-like activity which, however, is inhibited by dopamine (DA). Hence, less blue colored ox-TMB is formed by oxidation of 3,3',5,5'-tetramethylbenzidine in the presence of dopamine.


Assuntos
Materiais Biomiméticos/química , Cobalto/química , Colorimetria/métodos , Dopamina/análise , Grafite/química , Níquel/química , Óxidos/química , Oxirredutases/metabolismo , Sulfetos/química , Benzidinas/química , Dopamina/sangue , Eletroquímica , Humanos , Cinética
9.
Nano Lett ; 17(12): 7478-7486, 2017 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-29116798

RESUMO

Metal nanoparticle arrays are excellent candidates for a variety of applications due to the versatility of their morphology and structure at the nanoscale. Bottom-up self-assembly of metal nanoparticles provides an important complementary alternative to the traditional top-down lithography method and makes it possible to assemble structures with higher-order complexity, for example, nanospheres, nanocubes, and core-shell nanostructures. Here we present a mechanism study of the self-assembly process of 1-D noble metal nanoparticles arrays, composed of Au, Ag, and AuAg alloy nanoparticles. These are prepared within an encapsulated germanium nanowire, obtained by the oxidation of a metal-germanium nanowire hybrid structure. The resulting structure is a 1-D array of equidistant metal nanoparticles with the same diameter, the so-called nanobead (NB) array structure. Atom-probe tomography and transmission electron microscopy were utilized to investigate the details of the morphological and chemical evolution during the oxidation of the encapsulated metal-germanium nanowire hybrid-structures. The self-assembly of nanoparticles relies on the formation of a metal-germanium liquid alloy and the migration of the liquid alloy into the nanowire, followed by dewetting of the liquid during shape-confined oxidation where the liquid column breaks-up into nanoparticles due to the Plateau-Rayleigh instability. Our results demonstrate that the encapsulating oxide layer serves as a structural scaffold, retaining the overall shape during the eutectic liquid formation and demonstrates the relationship between the oxide mechanical properties and the final structural characteristics of the 1-D arrays. The mechanistic details revealed here provide a versatile tool-box for the bottom-up fabrication of 1-D arrays nanopatterning that can be modified for multiple applications according to the RedOx properties of the material system components.

10.
Sensors (Basel) ; 17(1)2017 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-28106850

RESUMO

Integrating plasmonic materials, like gold with a two-dimensional material (e.g., graphene) enhances the light-material interaction and, hence, plasmonic properties of the metallic nanostructure. A localized surface plasmon resonance sensor is an effective platform for biomarker detection. They offer a better bulk surface (local) sensitivity than a regular surface plasmon resonance (SPR) sensor; however, they suffer from a lower figure of merit compared to that one in a propagating surface plasmon resonance sensors. In this work, a decorated multilayer graphene film with an Au nanostructures was proposed as a liquid sensor. The results showed a significant improvement in the figure of merit compared with other reported localized surface plasmon resonance sensors. The maximum figure of merit and intensity sensitivity of 240 and 55 RIU-1 (refractive index unit) at refractive index change of 0.001 were achieved which indicate the capability of the proposed sensor to detect a small change in concentration of liquids in the ng/mL level which is essential in early-stage cancer disease detection.

11.
J Aerosol Sci ; 86: 44-54, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32226126

RESUMO

Controlling airborne microorganisms has become increasingly important with increase in human indoor activities, epidemic disease outbreaks, and airborne pathogen transmission. Treatments using antimicrobial nanoparticles have shown promise because of the high surface-to-volume ratio of nanoparticles compared to their bulk counterparts, and their unique physical and chemical properties. In this study, hybrid nanostructures of multi-walled carbon nanotubes (MWCNTs) coated with antimicrobial, natural product (NP) nanoparticles were synthesized using a twin-head electrospray system (THES). The coated nanoparticles were then used in antimicrobial air filters to increase their antimicrobial efficiency. Electrosprayed droplets were converted to NP nanoparticles and MWCNTs through ethanol evaporation. Oppositely charged NP nanoparticles and MWCNTs were coagulated via Coulombic collisions to form hybrid nanoparticles that were deposited continuously onto an air filter medium. The size distribution and composition of the hybrid NP/MWCNT particles were characterized using a wide-range particle spectrometer (WPS) and transmission electron microscope (TEM). The concentration of hybrid NP/MWCNT nanoparticles was lower than that of NP nanoparticles but higher than that of MWCNTs and showed a bimodal size distribution with peak diameters of 21.1 and 49 nm. TEM analyses confirmed that the NP nanoparticles were attached to the MWCNT surface with a density of ~4-9 particles/MWCNT. When deposited onto the filter medium, NP/MWCNT particles formed dendrites on the filter׳s fiber surface. The filtration efficiency and pressure drop of the NP/MWCNT-coated filters were higher than those of pristine, NP nanoparticles-coated or MWCNTs-coated filters. The hybrid filter also exhibited stronger antimicrobial activity than those of NP or MWCNT-coated filters at identical deposited volumes (1.1×10-2 cm3/cm2 filter). Ninety-five percent of the tested bacterial aerosols were inactivated on the NP/MWCNTs filter while only <70% were inactivated on NP- or MWCNT-coated filters.

12.
Nanomaterials (Basel) ; 14(8)2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38668200

RESUMO

Nitrite monitoring serves as a fundamental practice for protecting public health, preserving environmental quality, ensuring food safety, maintaining industrial safety standards, and optimizing agricultural practices. Although many nitrite sensing methods have been recently developed, the quantification of nitrite remains challenging due to sensitivity and selectivity limitations. In this context, we present the fabrication of enzymeless iron oxide nanoparticle-modified zinc oxide nanorod (α-Fe2O3-ZnO NR) hybrid nanostructure-based nitrite sensor fabrication. The α-Fe2O3-ZnO NR hybrid nanostructure was synthesized using a two-step hydrothermal method and characterized in detail utilizing x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). These analyses confirm the successful synthesis of an α-Fe2O3-ZnO NR hybrid nanostructure, highlighting its morphology, purity, crystallinity, and elemental constituents. The α-Fe2O3-ZnO NR hybrid nanostructure was used to modify the SPCE (screen-printed carbon electrode) for enzymeless nitrite sensor fabrication. The voltammetric methods (i.e., cyclic voltammetry (CV) and differential pulse voltammetry (DPV)) were employed to explore the electrochemical characteristics of α-Fe2O3-ZnO NR/SPCE sensors for nitrite. Upon examination of the sensor's electrochemical behavior across a range of nitrite concentrations (0 to 500 µM), it is evident that the α-Fe2O3-ZnO NR hybrid nanostructure shows an increased response with increasing nitrite concentration. The sensor demonstrates a linear response to nitrite concentrations up to 400 µM, a remarkable sensitivity of 18.10 µA µM-1 cm-2, and a notably low detection threshold of 0.16 µM. Furthermore, its exceptional selectivity, stability, and reproducibility make it an ideal tool for accurately measuring nitrite levels in serum, yielding reliable outcomes. This advancement heralds a significant step forward in the field of environmental monitoring, offering a potent solution for the precise assessment of nitrite pollution.

13.
Macromol Rapid Commun ; 34(20): 1635-41, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24030971

RESUMO

The synthesis of thiol-functionalized long-chain highly branched polymers (LCHBPs) has been accomplished in combination of ring-opening metathesis polymerization (ROMP) and thiol-Michael addition click reaction. A monotelechelic polymer with a terminal acrylate and many pendent thiol groups is first prepared through adding an internal cis-olefin terminating agent to the reaction mixture immediately after the completion of the living ROMP, and then utilized as an ABn -type macromonomer in subsequent thiol-ene reaction between acrylate and thiol, yielding LCHBPs as the reaction time prolonged. Au nanoparticles are then covalently conjugated onto the surface of thiol-functionalized LCHBP to fabricate novel hybrid nanostructures, which is shown as one interesting application of such functionalized metathesis polymers. This facile approach can be extended toward the fabrication of novel nanomaterials with sophisticated structures and tunable multifunctionalities.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Polímeros/síntese química , Compostos de Sulfidrila/química , Acrilatos/química , Alcenos/química , Catálise , Norbornanos/química , Polímeros/química
14.
ACS Appl Mater Interfaces ; 15(33): 39505-39512, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37551922

RESUMO

Upgraded technology has realized miniaturization and promoted transformation in each field. Miniaturized light-emitting diode (LED) chips enable higher resolution and create a full sense of immersion in displays. Porous GaN is a structure that can reduce excitation light leakage and enhance the light conversion efficiency. Perovskite quantum dots with the highest optical density as candidate materials for loading in pores can significantly decrease the aggregation phenomenon and increase the path of light absorption. Here, the porous tunability is explored by electrochemical etching under a range of voltages, concentrations, and etching times with acid and base electrolytes, such as oxalic acid and potassium hydroxide. Based on scanning electron microscopy images, the distribution of the pores and the morphology of pore channels can be distinguished under acid and base etching. Larger pore sizes and distorted channels (∼680 nm) are presented on the oxalic acid-etched GaN chip. In contrast, smaller pore sizes and straight-deeper channels (∼5650 nm) are demonstrated on the GaN by potassium hydroxide etching. Therefore, the hybrid nanostructure is etched by oxalic acid and potassium hydroxide, separately. The green and red light conversion efficiencies of perovskite quantum dots pumped by a blue LED can be improved by 3 and 10 times, respectively, resulting in a color gamut of approximately 124%.

15.
J Colloid Interface Sci ; 649: 826-831, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37390530

RESUMO

Highly site-specific growth of gold nanoparticles (AuNPs) on Bismuth Selenide (Bi2Se3) hexagonal nanoplates was achieved by fine-tuning the growth kinetics of Au through controlling the coordination number of the Au ion in MBIA-Au3+ complex. With increasing concentration of MBIA, the increased amount and the coordination number of the MBIA-Au3+ complex results in the decrease of the reduction rate of Au. The slowed growth kinetics of Au allowed the recognition of the sites with different surface energy on the anisotropic Bi2Se3 hexagonal nanoplates. As a result, the site-specific growth of AuNPs at the corner, the edge, and the surface of the Bi2Se3 nanoplates were successfully achieved. This way of growth kinetic control was proven to be effective in constructing well-defined heterostructures with precise site-specificity and high purity of the product. This is helpful for the rational design and controlled synthesis of sophisticated hybrid nanostructures and would eventually promote their applications in various fields.

16.
Polymers (Basel) ; 15(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36679162

RESUMO

A new era is rising in food packaging and preservation, with a consequent focus on transition to "greener" and environmentally friendly techniques. The environmental problems that are emerging nowadays impose use of natural materials for food packaging applications, replacement of chemical preservatives with natural organic extractions, such as essential oils, and targeting of new achievements, such as further extension of food shelf-life. According to this new philosophy, most of the used materials for food packaging should be recyclable, natural or bio-based, and/or edible. The aim of this work was to investigate use and efficiency of a novel food packaging developed based on commercial LDPE polymer incorporated with natural material halloysite impregnated with natural extract of thyme oil. Moreover, a direct correlation between the stiff TBARS method and the easiest heme iron measurements method was scanned to test food lesions easier and faster. The result of this study was development of the LDPE/10TO@HNT film, which contains the optimum amount of a hybrid nanostructure and is capable to be used as an efficient active food packaging film. Furthermore, a linear correlation seems to connect the TBARS and heme iron measurements.

17.
Biosens Bioelectron ; 221: 114904, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36450169

RESUMO

Here, we introduce a power-free foldable poly(methyl methacrylate) (PMMA) microdevice fully integrating DNA extraction, amplification, and visual detection, realized in novel dual modes - colorimetric and aggregate formation - using 4-Aminoantipyrine (4-AP) for monitoring pathogens. The microdevice contains two parts: reaction and detection zones. A sealing film was utilized to connect the two zones and make the device foldable. The FTA card was deposited in the reaction zone for DNA extraction, followed by loop-mediated isothermal amplification (LAMP) at 65 °C for 45 min. When the detection zone is folded toward the reaction zone, paper discs modified with 4-AP placed in the detection zone are delivered to the reaction zone. Specifically, in the presence of LAMP amplicons, 4-AP is oxidized into antipyrine red or generates aggregates by interacting with copper sulfate, forming copper hybrid nanostructure (Cu-hNs). In the absence of LAMP amplicons, 4-AP is not oxidized and maintains yellow color or fails to form aggregates. Furthermore, we introduced the ethidium homodimer-1 (EthD-1) to identify viable bacteria. EthD-1 penetrated the compromised membranes of nonviable cells and prevented further DNA amplification by intercalating with the DNA. In this way, only samples containing viable cells displayed color change or formed aggregates upon reaction with 4-AP. Using this method, SARS-CoV-2 RNA and Enterococcus faecium were identified by naked eye, with the limit of detection of 103 copies/µL and 102 CFU/mL, respectively, within 60 min. The introduced microdevice can be used for rapidly monitoring viable pathogens and controlling outbreaks of infectious disease in resource-limited settings.


Assuntos
Técnicas Biossensoriais , COVID-19 , Humanos , RNA Viral , COVID-19/diagnóstico , SARS-CoV-2/genética , Testes Imediatos
18.
ACS Appl Mater Interfaces ; 14(8): 10577-10587, 2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35188369

RESUMO

Metal-organic frameworks (MOFs) are booming as a promising precursor for constructing lightweight, high-efficiency microwave absorbing (MA) material. However, it is still a challenge to rationally design three-dimensional (3D), porous MOF-derived MA materials with a stable structure and strong and wideband MA performance. Herein, a 3D hybrid nanostructure (CNT/FeCoNi@C) comprising MOF-derived magnetic nanospheres and Fe-filled carbon nanotube (CNT) sponge has been controllably fabricated to enhance the absorption ability and broaden the effective absorption bandwidth (EAB). The magnetic nanospheres are uniformly anchored on the CNT skeleton, forming hybrid network structures, which enhance interface polarization, electron transportation, and impedance matching. The minimum reflection loss (RL) and EAB of the as-prepared CNT/FeCoNi@C sponges reach -51.7 dB and 6.0 GHz, respectively, outperforming most reported MOF-based wave absorbers. This work provides not only a novel design of MOF-derived 3D nanostructures but also an effective guide for the optimization of electromagnetic properties and absorbing performance in MA material.

19.
J Colloid Interface Sci ; 628(Pt A): 508-518, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-35933868

RESUMO

Obtaining of non-noble metal catalyst with bifunctional effect for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water splitting is highly desired to get high purity hydrogen. Here in, we design and fabricate Cu/Ni bimetallic phosphides with Graphdiyne (GDY) to form hybrid nanomaterial CuNiPx-GDY on Ni foam for the first time. The synergistical effect between GDY and transition metal phosphides, and the atomic scale heterojunctions between Cu3P and Ni2P, effectively accelerate the catalytical process both in HER and OER, resulting in extraordinarily small overpotentials of 178 mV and 110 mV at 10 mA cm-2 for OER and HER in CuNiPx-GDY(1:1) in 1 M KOH, respectively. Density functional theory results show that, compared with pure CuNiPx, the introduced GDY can considerably improve the activity of OER and generate different active sites for OER and HER in CuNiPx-GDY(1:1). Thus CuNiPx-GDY(1:1) exhibits good catalytical performance and stability as catalyst for overall water splitting. This study provides a new sight into the structure and catalytic properties of GDY and transition metal phosphides hybrid nanomaterial, and also offers a new way to obtain advanced materials with remarkable catalytic properties.

20.
J Colloid Interface Sci ; 608(Pt 3): 3040-3048, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34815080

RESUMO

High efficient and durable catalysts are always needed to lower the kinetic barriers as well as prolong the service life associated with oxygen evolution reaction (OER). Herein, a sequential synthetic strategy is considered to prepare a hierarchical nanostructure, in which each component can be configured to achieve their full potential so that endows the resulting nanocatalyst a good overall performance. In order to realize this, well-organized cobalt oxide (Co3O4) nanopillars are firstly grown onto ultrathin 1T-molybdenum sulfide (1T-MoS2) to obtain high surface area electrocatalyst, providing electron transfer pathways and structural stability. After that, zeolitic imidazolate framework-67 (ZIF-67) derived carbonization film is further in situ deposited on the surface of nanopillars to generate plentiful active sites, thereby accelerating OER kinetics. Based on the combination of different components, the electron transfer capability, catalytic activity and durability are optimized and fully implemented. The obtained nanocatalyst (defined as 1T-MoS2/Co3O4/CN) exhibits the superior OER catalytic ability with the overpotential of 202 mV and Tafel slope of 57 mV·dec-1 at 10 mA·cm-2 in 0.1 M KOH, and good durability with a minor chronoamperometric decay of 9.15 % after 60,000 s of polarization.

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