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1.
Chemosphere ; 286(Pt 2): 131826, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34426141

RESUMO

Pesticides play critical roles in agricultural fields; however, pesticide residues can cause serious damage to human health and the ecological environment; therefore, developing a rapid and sensitive method for pesticide detection is urgently needed. Nanostructure-assisted matrix laser desorption/ionization (MALDI) mass spectrometry (MS) has great potential for the detection of low-mass pesticides. In this study, a novel Ti3C2 MXene nanowire (TMN) was prepared by a facile sol-gel method and served as a matrix to enhance MALDI MS performance in the analysis of pesticides in positive ion mode. The TMN showed superior performance in the high-throughput detection of six kinds of pesticides (organophosphorus, organochlorine, carbamate, neonicotinoids, triazole, and oxadiazines), with ultrahigh sensitivity (detection limits at sub-ppt levels), remarkable repeatability, excellent salt tolerance, and extremely low background compared to traditional organic matrices due to the specific polyaromatic structure and the doping of nitrogen. Furthermore, this matrix was successfully employed for the analysis of residual pesticides in traditional Chinese herbs, and the level of diniconazole was quantified with a linear range of 0-50 ng/mL (R2 > 0.99). More importantly, the spatial distribution of various endogenous compounds (e.g., amino acids and saccharides, fatty acids, alkaloids, and plant hormones) and xenobiotic pesticides from the intact root of the medicinal plant P. quinquefolium was clearly visualized using the TMN self-assembly film as a matrix for MALDI imaging mass spectrometry (IMS). With superior advantages such as sensitivity, simplicity, rapidness, and minimal sample requirement, TMN as a matrix-assisted MALDI MS shows great promise for various applications.


Assuntos
Nanofios , Praguicidas , Ensaios de Triagem em Larga Escala , Humanos , Lasers , Praguicidas/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Titânio
2.
Appl Microbiol Biotechnol ; 105(21-22): 8255-8264, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34599676

RESUMO

Using a virus as a template to synthesize nanomaterial is a simple, green, and controllable method to acquire unique structure nanoparticles. In this study, CdS nanowires were synthesized using the tobacco mosaic virus (TMV) as a template and for deposition in the inner center channel of TMV. TMV/CdS was successfully characterized, with the results showing a diameter of 4.0 nm, a cubic-phase composition, and strong fluorescence emission peaks, with an absorption edge of 566 nm and bandgap energy of 2.28 eV. The bandgap energy is narrower than that of template-free CdS. Furthermore, TMV/CdS exhibited an increased transient photocurrent, which was attributed to the effective separation of electron-hole pairs. The photoactivities of TMV/CdS and template-free CdS were tested; the results showed that the TMV/CdS had a better performance in methylene blue (MB) photodegradation, indicating that the photoactivity of TMV/CdS was higher than that of the template-free CdS. Further research on TMV/CdS regarding the photocatalytic mechanism showed that O2•- and •OH were the major species involved in photocatalysis, rather than holes (h+). Therefore, TMV/CdS might have applications as a novel visible-light-responsive photocatalyst. KEY POINTS: • CdS nanowires were firstly synthesized in the inner center channel of TMV • TMV/CdS presented higher photocatalytic efficiency compared with template-free CdS • The O2•- and •OH were responsible for the photocatalytic reaction of TMV/CdS.


Assuntos
Nanoestruturas , Nanofios , Vírus do Mosaico do Tabaco , Catálise , Luz
3.
Analyst ; 146(22): 6684-6725, 2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34667998

RESUMO

Detection and recognition of chemical and biological species via sensor electronics are important not only for various sensing applications but also for fundamental scientific understanding. In the past two decades, sensor devices using one-dimensional (1D) nanowires have emerged as promising and powerful platforms for electrical detection of chemical species and biologically relevant molecules due to their superior sensing performance, long-term stability, and ultra-low power consumption. This paper presents a comprehensive overview of the recent progress and achievements in 1D nanowire synthesis, working principles of nanowire-based sensors, and the applications of nanowire-based sensor electronics in chemical and biological analytes detection and recognition. In addition, some critical issues that hinder the practical applications of 1D nanowire-based sensor electronics, including device reproducibility and selectivity, stability, and power consumption, will be highlighted. Finally, challenges, perspectives, and opportunities for developing advanced and innovative nanowire-based sensor electronics in chemical and biological applications are featured.


Assuntos
Nanofios , Eletrônica , Reprodutibilidade dos Testes
4.
Biosensors (Basel) ; 11(10)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34677307

RESUMO

This work describes the facile preparation of a disposable electrochemical biosensor for the detection of Hg(II) in water by modifying the surface of a screen-printed carbon electrode (SPCE). The surface modification consists of the immobilization of a composite layer of silver nanowires, hydroxymethyl propyl cellulose, chitosan, and urease (AgNWs/HPMC/CS/Urease). The presence of the composite was confirmed by scanning electron microscopy (SEM) and its excellent conductivity, due chiefly to the electrical properties of silver nanowires, enhanced the sensitivity of the biosensor. Under optimum conditions, the modified SPCE biosensor showed excellent performance for the detection of Hg(II) ions, with an incubation time of 10 min and a linear sensitivity range of 5-25 µM. The limit of detection (LOD) and limit of quantitation (LOQ) were observed to be 3.94 µM and 6.50 µM, respectively. In addition, the disposable and portable biosensor exhibited excellent recoveries for the detection of Hg(II) ions in commercial drinking water samples (101.62-105.26%). The results are correlated with those obtained from inductively coupled plasma optical emission spectrometry (ICP-OES), indicating that our developed sensor is a reliable method for detection of Hg(II) in real water samples. The developed sensor device is a simple, effective, portable, low cost, and user-friendly platform for real-time detection of heavy metal ions in field measurements with potential for other biomedical applications in the future.


Assuntos
Mercúrio/análise , Poluentes Químicos da Água/análise , Técnicas Biossensoriais , Técnicas Eletroquímicas , Monitoramento Ambiental , Limite de Detecção , Nanofios
5.
Nature ; 597(7876): 430-434, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34471289

RESUMO

Extracellular electron transfer by Geobacter species through surface appendages known as microbial nanowires1 is important in a range of globally important environmental phenomena2, as well as for applications in bio-remediation, bioenergy, biofuels and bioelectronics. Since 2005, these nanowires have been thought to be type 4 pili composed solely of the PilA-N protein1. However, previous structural analyses have demonstrated that, during extracellular electron transfer, cells do not produce pili but rather nanowires made up of the cytochromes OmcS2,3 and OmcZ4. Here we show that Geobacter sulfurreducens binds PilA-N to PilA-C to assemble heterodimeric pili, which remain periplasmic under nanowire-producing conditions that require extracellular electron transfer5. Cryo-electron microscopy revealed that C-terminal residues of PilA-N stabilize its copolymerization with PilA-C (to form PilA-N-C) through electrostatic and hydrophobic interactions that position PilA-C along the outer surface of the filament. PilA-N-C filaments lack π-stacking of aromatic side chains and show a conductivity that is 20,000-fold lower than that of OmcZ nanowires. In contrast with surface-displayed type 4 pili, PilA-N-C filaments show structure, function and localization akin to those of type 2 secretion pseudopili6. The secretion of OmcS and OmcZ nanowires is lost when pilA-N is deleted and restored when PilA-N-C filaments are reconstituted. The substitution of pilA-N with the type 4 pili of other microorganisms also causes a loss of secretion of OmcZ nanowires. As all major phyla of prokaryotes use systems similar to type 4 pili, this nanowire translocation machinery may have a widespread effect in identifying the evolution and prevalence of diverse electron-transferring microorganisms and in determining nanowire assembly architecture for designing synthetic protein nanowires.


Assuntos
Fímbrias Bacterianas/química , Fímbrias Bacterianas/metabolismo , Geobacter , Nanofios , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Biopolímeros , Condutividade Elétrica , Proteínas de Fímbrias/química , Proteínas de Fímbrias/metabolismo , Geobacter/citologia , Geobacter/metabolismo , Multimerização Proteica
6.
Proc Natl Acad Sci U S A ; 118(39)2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34556577

RESUMO

Proteins achieve efficient energy storage and conversion through electron transfer along a series of redox cofactors. Multiheme cytochromes are notable examples. These proteins transfer electrons over distance scales of several nanometers to >10 µm and in so doing they couple cellular metabolism with extracellular redox partners including electrodes. Here, we report pump-probe spectroscopy that provides a direct measure of the intrinsic rates of heme-heme electron transfer in this fascinating class of proteins. Our study took advantage of a spectrally unique His/Met-ligated heme introduced at a defined site within the decaheme extracellular MtrC protein of Shewanella oneidensis We observed rates of heme-to-heme electron transfer on the order of 109 s-1 (3.7 to 4.3 Å edge-to-edge distance), in good agreement with predictions based on density functional and molecular dynamics calculations. These rates are among the highest reported for ground-state electron transfer in biology. Yet, some fall 2 to 3 orders of magnitude below the Moser-Dutton ruler because electron transfer at these short distances is through space and therefore associated with a higher tunneling barrier than the through-protein tunneling scenario that is usual at longer distances. Moreover, we show that the His/Met-ligated heme creates an electron sink that stabilizes the charge separated state on the 100-µs time scale. This feature could be exploited in future designs of multiheme cytochromes as components of versatile photosynthetic biohybrid assemblies.


Assuntos
Grupo dos Citocromos c/metabolismo , Citocromos/metabolismo , Elétrons , Heme/metabolismo , Histidina/metabolismo , Metionina/metabolismo , Shewanella/metabolismo , Grupo dos Citocromos c/química , Citocromos/química , Transporte de Elétrons , Heme/química , Histidina/química , Metionina/química , Simulação de Dinâmica Molecular , Nanofios , Oxirredução
7.
Biosens Bioelectron ; 194: 113600, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34481242

RESUMO

A sensitive electrogenerated chemiluminescence (ECL) biosensor for glucose was developed based on in situ growth of TiO2 nanowires on Ti3C2 MXenes (TiO2-Ti3C2) as the nanoplatform. Via tuning the alkaline oxidation time, different amount of TiO2 nanowires can be found on MXenes. An ECL biosensor for glucose was constructed by covalent immobilization of glucose oxidase (GODx) on the glycine functional TiO2-Ti3C2 surface, with the ECL signal depending on the in-situ formation of H2O2 via the specifically catalysis of glucose by GODx, resulting in the apparent increase of ECL signal. The TiO2-Ti3C2 can also act as the catalyst for the oxidation of H2O2 into O2 to enhance the ECL of luminol. Based on this strategy, a highly sensitive ECL biosensor for glucose was obtained in wide concentration range of 20 nM-12 mM with a low detection limit of 1.2 nM (S/N = 3). The synergistic effects of large surface area, excellent conductivity, and high catalytic activity of the TiO2-Ti3C2 make the sensor highly sensitive toward glucose; the specific enzyme catalysis reaction promises excellent selectivity of the ECL sensor. The proposed biosensor has been employed to detect glucose in human serum, fruits, and sweat samples with excellent performance, providing a universal approach for glucose in various samples, which shows great prospect in clinical diagnostics and wearable sensors.


Assuntos
Técnicas Biossensoriais , Nanofios , Frutas , Glucose , Ouro , Humanos , Peróxido de Hidrogênio , Medições Luminescentes , Luminol , Suor , Titânio
8.
Biosens Bioelectron ; 194: 113589, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34543824

RESUMO

Extracellular vesicles (EVs) have shown promising features as biomarkers for early cancer diagnoses. The outer layer of cancer cell-derived EVs consists of organotropic metastasis-induced membrane proteins and specifically enriched proteoglycans, and these molecular compositions determine EV surface charge. Although many efforts have been devoted to investigating the correlation between EV subsets obtained through density-, size-, and immunoaffinity-based captures and expressed membrane proteins, understanding the correlation between EV subsets obtained through surface charge-based capture and expressed membrane proteins is lacking. Here, we propose a methodology to profile membrane proteins of EV subsets obtained through surface charge-based capture. Nanowire-induced charge-based capture of EVs and in-situ profiling of EV membrane proteins are the two key methodology points. The oxide nanowires allowed EVs to be obtained through surface charge-based capture due to the diverse isoelectric points of the oxides and the large surface-to-volume ratios of the nanowire structures. And, with the ZnO nanowire device, whose use does not require any purification and concentration processes, we demonstrated the correlation between negatively-charged EV subsets and expressed membrane proteins derived from each cell. Furthermore, we determined that a colon cancer related membrane protein was overexpressed on negatively charged surface EVs derived from colon cancer cells.


Assuntos
Técnicas Biossensoriais , Vesículas Extracelulares , Nanofios , Microfluídica , Óxidos
9.
Talanta ; 235: 122748, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517616

RESUMO

Cancer-derived exosomes have emerged as a valuable biomarker for cancer diagnosis and prognosis. However, the heterogeneity of exosomes often leads to low selectivity based on the single recognition method. Given this, we have developed a dual-aptamer recognition strategy based on G-quadruplex nanowires for selective analysis of exosomes. In this work, target exosomes were first captured by CD63 aptamers modified on magnetic beads (MBs) and then combined with AS1411 aptamer, which shows high binding affinity to nucleolin when forming stable G-quadruplex structure. Then the free myc monomer can spontaneously assemble into higher order G-wire superstructures on the allosteric AS1411, and resulting enhanced fluorescence signal, which can realize sensitive and specific analysis of the target exosomes. This dual-aptamer recognition-based method is simple and universal for different types of exosomes, which is of great significance for clinical cancer diagnosis.


Assuntos
Aptâmeros de Nucleotídeos , Exossomos , Quadruplex G , Nanofios , Neoplasias , Humanos
10.
Nano Lett ; 21(18): 7542-7547, 2021 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-34505784

RESUMO

Nanowires are an increasingly prevalent class of nanomaterials in composites and devices, with arrays and other complex geometries used in various applications. Little investigation has been done regarding the mechanical behavior of micron-sized nanowire structures. We conduct in situ microcompression experiments on vertically aligned dense microbundles of 300 nm diameter single-crystalline zinc oxide nanowires to gain insights into their structural failure. Experiments demonstrate that bundles containing approximately 10-130 nanowires experience two failure regimes: (1) localized noncatastrophic interfacial splitting and (2) global structural failure. Utilizing Weibull statistics and experimental results, we develop a technique for analyzing flaw distribution and use it to predict the expected range of bundle failure stress. This analysis provides guidelines for nanowire arrays' susceptibility to failure, sensitivity to flaw size, interfacial interactions of constituents, and degree of alignment. This work develops insights to understand and predict fundamental failure mechanisms in highly aligned, dense structures.


Assuntos
Nanoestruturas , Nanofios , Óxido de Zinco
11.
Anal Chem ; 93(39): 13334-13341, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34553919

RESUMO

Herein, a versatile ECL biosensor was fabricated for ultrasensitive detection of microRNA-21 (miRNA-21) from cancer cells based on a novel H2O2-free electrochemiluminescence (ECL) system (luminol/dissolved oxygen/Fe@Fe2O3 nanowires). Compared with the previously reported coreaction accelerator that needed a negative potential to produce reactive oxygen species (ROS), these newly discovered Fe@Fe2O3 nanowires could generate ROS in the detection solution immediately without the application of voltage, which narrowed down the detection potential range to avoid side reactions, favoring their practical application in biological systems. Especially, the Fe@Fe2O3 nanowires could produce H• for activating dissolved oxygen into ROS to improve the ECL intensity dramatically, which initiates a novel pathway to promote the generation of ROS for the ECL system. In addition, an original strand displacement amplification coupled with strand displacement reaction (SDA-SDR) was developed to improve the conversion efficiency of the target for sensitive detection of miRNA-21. By virtue of the SDR, a quadruple quenching effect was achieved through each output DNA strand of SDA; hence, the nucleic acid signal amplification efficiency was effectively enhanced. As expected, on account of the superb activation performance of Fe@Fe2O3 nanowires and the outstanding amplification efficiency of the SDR-SDA strategy, the fabricated ECL biosensor realized ultrasensitive detection of miRNA-21 with a detection limit down to 52.5 aM. The established ECL sensing platform ushered a new route for H2O2-free detection and a promising biomarker assay method for clinical diagnosis.


Assuntos
MicroRNAs , Nanofios , Luminol , Oxigênio
12.
Biosensors (Basel) ; 11(9)2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34562932

RESUMO

Creatinine has become an important indicator for the early detection of uremia. However, due to the disadvantages of external power supply and large volume, some commercial devices for detecting creatinine concentration have lost a lot of popularity in everyday life. This paper describes the development of a self-powered biosensor for detecting creatinine in sweat. The biosensor can detect human creatinine levels in real time without the need for an external power source, providing information about the body's overall health. The piezoelectric output voltage of creatininase/creatinase/sarcosine oxidase-modified ZnO nanowires (NWs) is significantly dependent on the creatinine concentration due to the coupling effect of the piezoelectric effect and enzymatic reaction (piezo-enzymatic-reaction effect), which can be regarded as both electrical energy and biosensing signal. Our results can be used for the detection of creatinine levels in the human body and have great potential in the prediction of related diseases.


Assuntos
Técnicas Biossensoriais , Nanofios , Amidoidrolases , Creatinina , Fontes de Energia Elétrica , Eletricidade , Humanos , Suor , Ureo-Hidrolases , Óxido de Zinco/química
13.
Biosensors (Basel) ; 11(7)2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34356707

RESUMO

Nanoribbon chips, based on "silicon-on-insulator" structures (SOI-NR chips), have been fabricated. These SOI-NR chips, whose surface was sensitized with covalently immobilized oligonucleotide molecular probes (oDNA probes), have been employed for the nanoribbon biosensor-based detection of a circular ribonucleic acid (circRNA) molecular marker of glioma in humans. The nucleotide sequence of the oDNA probes was complimentary to the sequence of the target oDNA. The latter represents a synthetic analogue of a glioma marker-NFIX circular RNA. In this way, the detection of target oDNA molecules in a pure buffer has been performed. The lowest concentration of the target biomolecules, detectable in our experiments, was of the order of ~10-17 M. The SOI-NR sensor chips proposed herein have allowed us to reveal an elevated level of the NFIX circular RNA in the blood of a glioma patient.


Assuntos
Técnicas Biossensoriais , Glioma , MicroRNAs , Eletrônica , Humanos , Nanotubos de Carbono , Nanofios , Oligonucleotídeos , Silício , Transistores Eletrônicos
14.
Nano Lett ; 21(17): 7388-7395, 2021 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-34424703

RESUMO

Highly compact, filter-free multispectral photodetectors have important applications in biological imaging, face recognition, and remote sensing. In this work, we demonstrate room-temperature wavelength-selective multipixel photodetectors based on GaAs0.94Sb0.06 nanowire arrays grown by metalorganic vapor phase epitaxy, providing more than 10 light detection channels covering both visible and near-infrared ranges without using any optical filters. The nanowire array geometry-related tunable spectral photoresponse has been demonstrated both theoretically and experimentally and shown to be originated from the strong and tunable resonance modes that are supported in the GaAsSb array nanowires. High responsivity and detectivity (up to 44.9 A/W and 1.2 × 1012 cm √Hz/W at 1 V, respectively) were obtained from the array photodetectors, enabling high-resolution RGB color imaging by applying such a nanowire array based single pixel imager. The results indicate that our filter-free wavelength-selective GaAsSb nanowire array photodetectors are promising candidates for the development of future high-quality multispectral imagers.


Assuntos
Nanofios , Diagnóstico por Imagem
15.
Biomolecules ; 11(7)2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34356651

RESUMO

In recent years, multidrug-resistant (MDR) bacteria have increased rapidly, representing a major threat to human health. This problem has created an urgent need to identify alternatives for the treatment of MDR bacteria. The aim of this study was to identify the antibacterial activity of selenium nanoparticles (SeNPs) and selenium nanowires (SeNWs) against MDR bacteria and assess the potential synergistic effects when combined with a conventional antibiotic (linezolid). SeNPs and SeNWs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), zeta potential, and UV-visible analysis. The antibacterial effects of SeNPs and SeNWs were confirmed by the macro-dilution minimum inhibitory concentration (MIC) test. SeNPs showed MIC values against methicillin-sensitive S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), vancomycin-resistant S. aureus (VRSA), and vancomycin-resistant enterococci (VRE) at concentrations of 20, 80, 320, and >320 µg/mL, respectively. On the other hand, SeNWs showed a MIC value of >320 µg/mL against all tested bacteria. Therefore, MSSA, MRSA, and VRSA were selected for the bacteria to be tested, and SeNPs were selected as the antimicrobial agent for the following experiments. In the time-kill assay, SeNPs at a concentration of 4X MIC (80 and 320 µg/mL) showed bactericidal effects against MSSA and MRSA, respectively. At a concentration of 2X MIC (40 and 160 µg/mL), SeNPs showed bacteriostatic effects against MSSA and bactericidal effects against MRSA, respectively. In the synergy test, SeNPs showed a synergistic effect with linezolid (LZD) through protein degradation against MSSA and MRSA. In conclusion, these results suggest that SeNPs can be candidates for antibacterial substitutes and supplements against MDR bacteria for topical use, such as dressings. However, for use in clinical situations, additional experiments such as toxicity and synergistic mechanism tests of SeNPs are needed.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Selênio/farmacologia , Antibacterianos/química , Proteínas de Bactérias/metabolismo , Contagem de Colônia Microbiana , Sinergismo Farmacológico , Enterococcus/efeitos dos fármacos , Linezolida/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/metabolismo , Testes de Sensibilidade Microbiana , Nanopartículas , Nanofios/química , Selênio/química , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Biosens Bioelectron ; 192: 113547, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34385013

RESUMO

Herein, a photocurrent polarity switching platform for highly selective assay of mucin 1 (MUC1) was developed based on target-induced hemin transfer from ZrO2 hollow spheres (ZrO2 HSs) to G-quadruplex nanowires (G wires). In this system, SiO2 spheres were used as templates to synthesize the uniform and mesoporous ZrO2 HSs. As nanocontainers, ZrO2 HSs could load hemin in its cavity via pores. Then, the aptamers of MUC1, as bio-gates, blocked the pores of ZrO2 HSs based on the specific binding of Zr4+ and the phosphate groups of aptamer. In the presence of MUC1, the aptamer could specifically recognize and bind with MUC1, and then leave away from the surface of ZrO2 HSs, which resulted in the opening of the bio-gates and releasing of hemin. Assisted with the G wires formed on the Au NPs/In2S3/ITO, the released hemin was captured on the electrode through the formation of hemin/G-quadruplex structure, leading to the switch of the photocurrent polarity of the electrode from anodic photocurrent to cathodic photocurrent. The proposed photoelectrochemical biosensor showed outstanding performance for MUC1 assay with high selectivity, wide linear response range (1 fg mL-1 -10 ng mL-1) and lower detection limit (0.48 fg mL-1). And the strategy could be easily extended to a triple-mode detection of MUC1 because the hemin/G-quadruplex structure was widely used in electrochemical and colorimetric methods as a hydrogen peroxide mimetic enzyme, which might provide wide applications in biological or clinical studies.


Assuntos
Técnicas Biossensoriais , DNA Catalítico , Quadruplex G , Nanofios , DNA Catalítico/metabolismo , Técnicas Eletroquímicas , Hemina , Limite de Detecção , Mucina-1 , Dióxido de Silício
17.
J Chromatogr A ; 1653: 462400, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34333171

RESUMO

Two kinds of TiO2 nanowires (TiO2NWs) with different orientation were in-situ grown on Ti substrates by controlling temperature and time during the hydrothermal process. The adsorption performance was evaluated by using typical aromatic compounds as model analytes coupled to HPLC with UV detection. The results demonstrated that the TiO2NWs coating grown at higher temperature within longer time had better affinity towards PAHs. For this purpose, the key experimental factors affecting the adsorption performance of the TiO2NWs coating fabricated at 200 °C for 10 h were further investigated and optimized for the extraction of PAHs. Under the optimized conditions, the proposed method presented linear responses in the concentration ranges of 0.05 to 200 µg·L-1 PAHs with correlation coefficients more than 0.998. LODs (S/N=3) were 0.008 to 0.034 µg·L-1. Moreover, RSDs for the single fiber repeatability of the intra-day and the inter-day analyses were less than 5.6% (n=5) and 5.8%, respectively. RSDs for the fiber-to-fiber reproducibility were between 5.1% and 6.5%. Finally, the proposed method was successfully applied to the selective preconcentration and determination of trace PAHs in environmental water samples. In addition, The fabricated Ti fiber can be used at least 200 times due to its high mechanical and chemical stability.


Assuntos
Monitoramento Ambiental , Nanofios , Hidrocarbonetos Policíclicos Aromáticos , Microextração em Fase Sólida , Temperatura , Titânio , Monitoramento Ambiental/métodos , Nanofios/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação , Reprodutibilidade dos Testes , Microextração em Fase Sólida/instrumentação , Titânio/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação
18.
Sensors (Basel) ; 21(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34372390

RESUMO

Silicon nanowire field-effect transistors (SiNW-FET) have been studied as ultra-high sensitive sensors for the detection of biomolecules, metal ions, gas molecules and as an interface for biological systems due to their remarkable electronic properties. "Bottom-up" or "top-down" approaches that are used for the fabrication of SiNW-FET sensors have their respective limitations in terms of technology development. The "bottom-up" approach allows the synthesis of silicon nanowires (SiNW) in the range from a few nm to hundreds of nm in diameter. However, it is technologically challenging to realize reproducible bottom-up devices on a large scale for clinical biosensing applications. The top-down approach involves state-of-the-art lithography and nanofabrication techniques to cast SiNW down to a few 10s of nanometers in diameter out of high-quality Silicon-on-Insulator (SOI) wafers in a controlled environment, enabling the large-scale fabrication of sensors for a myriad of applications. The possibility of their wafer-scale integration in standard semiconductor processes makes SiNW-FETs one of the most promising candidates for the next generation of biosensor platforms for applications in healthcare and medicine. Although advanced fabrication techniques are employed for fabricating SiNW, the sensor-to-sensor variation in the fabrication processes is one of the limiting factors for a large-scale production towards commercial applications. To provide a detailed overview of the technical aspects responsible for this sensor-to-sensor variation, we critically review and discuss the fundamental aspects that could lead to such a sensor-to-sensor variation, focusing on fabrication parameters and processes described in the state-of-the-art literature. Furthermore, we discuss the impact of functionalization aspects, surface modification, and system integration of the SiNW-FET biosensors on post-fabrication-induced sensor-to-sensor variations for biosensing experiments.


Assuntos
Técnicas Biossensoriais , Nanofios , Humanos , Silício , Transistores Eletrônicos
19.
ACS Appl Mater Interfaces ; 13(33): 39135-39141, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34374274

RESUMO

Many physiochemical properties of the extracellular matrix (ECM) of muscle tissues, such as nanometer scale dimension, nanotopography, negative charge, and elasticity, must be carefully reproduced to fabricate scaffold materials mimicking muscle tissues. Hence, we developed a muscle tissue ECM-mimicking scaffold using Mo6S3I6 inorganic molecular wires (IMWs). Composed of bio-essential elements and having a nanofibrous structure with a diameter of ∼1 nm and a negative surface charge with high stability, Mo6S3I6 IMWs are ideal for mimicking natural ECM molecules. Once Mo6S3I6 IMWs were patterned on a polydimethylsiloxane surface with an elasticity of 1877.1 ± 22.2 kPa, that is, comparable to that of muscle tissues, the proliferation and α-tubulin expression of myoblasts enhanced significantly. Additionally, the repetitive one-dimensional patterns of Mo6S3I6 IMWs induced the alignment and stretching of myoblasts with enhanced α-tubulin expression and differentiation into myocytes. This study demonstrates that Mo6S3I6 IMWs are promising for mimicking the ECM of muscle tissues.


Assuntos
Materiais Biomiméticos/química , Dimetilpolisiloxanos/química , Matriz Extracelular/metabolismo , Nanofios/química , Tecidos Suporte/química , Materiais Biomiméticos/metabolismo , Diferenciação Celular , Proliferação de Células/efeitos dos fármacos , Humanos , Iodo/química , Molibdênio/química , Músculos/citologia , Mioblastos/citologia , Mioblastos/metabolismo , Enxofre/química , Propriedades de Superfície , Engenharia Tecidual , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo
20.
Oncologist ; 26(10): e1683-e1692, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34272914

RESUMO

BACKGROUND: Next-generation sequencing has mostly been used for genotyping cell-free DNA (cfDNA) in plasma. However, this assay has several clinical limitations. We evaluated the clinical utility of a novel polymerase chain reaction-free nanowire (NW)-based plasma cfDNA assay for detecting ALK fusion and mutations. PATIENTS, MATERIALS, AND METHODS: We consecutively enrolled 99 patients with advanced non-small cell lung cancer undergoing a fluorescence in situ hybridization (FISH) test for ALK fusion; ALK-positive (n = 36). The NW-based assay was performed using 50-100 µL of plasma collected at pretreatment and every 8 weeks during ALK inhibitor treatment. RESULTS: There was high concordance between the NW-based assay and the FISH test for identification of ALK fusion (94.9% with a kappa coefficient value of 0.892, 95% confidence interval [CI], 0.799-0.984). There was no difference in the response rate to the first anaplastic lymphoma kinase inhibitor between the ALK-positive patients identified by the NW-based assay and by the FISH test (73.5% vs. 72.2%, p = .931). In the ALK variant analysis, variants 1 and 3 subgroups were detected in 27 (75.0%) and 8 (22.2%) patients, respectively. Among 24 patients treated with crizotinib, variant 3 subgroup was associated with worse median overall survival than variant 1 subgroup (36.5 months; 95% CI, 0.09-87.6 vs. 19.8 months; 95% CI, 9.9-not reached, p = .004]. A serial assessment identified that ALK L1196M resistance mutation emerged before radiologic progression during crizotinib treatment. CONCLUSION: The newly developed simple NW-based cfDNA assay may be clinically applicable for rapid diagnosis of ALK fusion with its variant forms and early detection of resistance. IMPLICATIONS FOR PRACTICE: The authors developed a novel one-step polymerase chain reaction-free nanowire (NW)-based plasma cell-free DNA (cfDNA) assay. This study evaluated the clinical utility of this novel method for the diagnosis of EML4-ALK fusion in advanced non-small cell lung cancer (NSCLC). The NW-based assay and FISH test showed high concordance rate in 99 patients with advanced NSCLC. Serial cfDNA assessment demonstrated this method provided early detection of resistance before radiologic progression during crizotinib treatment. Taken together, plasma cfDNA genotyping by the NW-based cfDNA assay may be useful for the rapid diagnosis of ALK fusion, classifying variants, and early detection of resistance.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Ácidos Nucleicos Livres , Neoplasias Pulmonares , Nanofios , Quinase do Linfoma Anaplásico/genética , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Ácidos Nucleicos Livres/genética , Humanos , Hibridização in Situ Fluorescente , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Proteínas de Fusão Oncogênica/genética , Inibidores de Proteínas Quinases/uso terapêutico
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