Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.762
Filtrar
1.
Talanta ; 207: 120340, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31594582

RESUMO

The emitter clogging is the most common hardware failure of nano-electrospray ionization, to improve the durability and electrospray stability of fused silica emitters, we demonstrate a means of fabricating nano-electrospray emitters with controllable aperture size and gradually-narrowed channel on the tip. We simulated the fluid morphologies in the emitter channels by computational fluid dynamics and found more stable flow on aperture-controllable nano-electrospray emitter. Besides, we found the unstable flow sections of commercial emitters match the actual clogging sections very well, indicating the main cause of emitter clogging is unstable flow. We further tested the emitters by nano-LC-MS based proteome analysis. Compared with the commercial emitter, aperture-controllable nano-electrospray emitters promoted the total ion chromatogram intensity by 25%, the number of identified proteins by 6.58%, and the number of identified peptides by 7.87%. In total, 989 proteins were identified from 1 µg of extracted mouse cardiac proteins. After the optimization by using mouse samples, we analyzed clinical auricular dextral tissues from patients undergoing cardiac surgery and found 16 proteins related to atrial fibrillation. Overall, aperture-controllable nano-electrospray emitter exhibits better sensitivity and reproducibility in the application of nano-LC-MS cardiac proteome analysis.


Assuntos
Miocárdio/metabolismo , Nanotecnologia/instrumentação , Proteômica/instrumentação , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Fibrilação Atrial/metabolismo , Simulação por Computador , Desenho de Equipamento , Humanos , Hidrodinâmica
2.
Chemphyschem ; 20(23): 3177-3180, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31639248

RESUMO

Herein, we report ultrasound-propelled graphene-oxide coated gold nanowire motors, functionalized with fluorescein-labeled DNA aptamers (FAM-AIB1-apt), for qualitative detection of overexpressed AIB1 oncoproteins in MCF-7 breast cancer cells. The movement of nanomotors under the ultrasound field facilitated intracellular uptake and resulted in a faster aptamer binding with the target protein and thus faster fluorescence recovery. The propulsion behavior of the aptamer functionalized nanomotors greatly enhanced the fluorescence intensity compared to static conditions. The new aptamer@nanomotor-based strategy offers considerable potential for further development of sensing methodologies towards diagnosis of breast cancer.


Assuntos
Aptâmeros de Nucleotídeos/metabolismo , Fluoresceína/química , Aptâmeros de Nucleotídeos/química , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Ouro/química , Humanos , Células MCF-7 , Microscopia Eletrônica de Varredura , Nanotecnologia/instrumentação , Nanotecnologia/métodos , Nanofios/química , Sonicação
3.
Nat Protoc ; 14(9): 2672-2690, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31391579

RESUMO

Understanding the photoinduced electron-transfer process is of paramount importance for realizing efficient solar energy conversion. It is rather difficult to clarify the link between the specific properties and the photoelectrochemical performance of an individual component in an ensemble system because data are usually presented as averages because of interplay of the heterogeneity of the bulk system. Here, we report a step-by-step protocol to fabricate an ultrasensitive photoelectrochemical platform for real-time detection of the intrinsic photoelectrochemical behaviors of a single entity with picoampere and sub-millisecond sensitivity. Using a micron-thickness nanoparticulate TiO2-filmed Au ultramicroelectrode (UME) as the electron-transport electrode, photocurrent transients can be observed for each individual dye-tagged oxide semiconductor nanoparticle collision associated with a single-entity photoelectrochemical reaction. This protocol allows researchers to obtain high-resolution photocurrent signals to quantify the photoinduced electron-transfer properties of an individual entity, as well as to precisely process the data obtained. We also include procedures for dynamic light scattering (DLS) analysis, transmission electron microscopy (TEM) imaging and collision frequency-concentration correlation to confirm that the photoelectrochemical collision events occur at an unambiguously single-entity level. The time required for the entire protocol is ~36 h, with a single-entity photoelectrochemical measurement taking <1 h to complete for each independent experiment. This protocol requires basic nanoelectrochemistry and nanotechnology skills, as well as an intermediate-level understanding of photoelectrochemistry.


Assuntos
Técnicas Eletroquímicas/métodos , Nanotecnologia/métodos , Fotoquímica/métodos , Técnicas Eletroquímicas/instrumentação , Elétrons , Desenho de Equipamento , Imagem Molecular , Nanoestruturas/química , Nanotecnologia/instrumentação , Fotoquímica/instrumentação , Pontos Quânticos/química , Titânio/química
4.
Anal Bioanal Chem ; 411(25): 6561-6573, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31444532

RESUMO

Self-propelled micromotors are micro- and nanoscale devices that move autonomously in solution by converting a specific stimulus into mechanical work. The broad scope of operations and applications along with the ultra-small dimensions have opened new possibilities to solve complex analytical challenges. Herein we give a critical overview of early developments and future prospects of such tiny moving objects for different analytical sensing and biosensing strategies. From early electrophoretic propelled nanomotors, which were limited to low viscous media, to bubble-propelled micromotors, the field has evolved into sophisticated all-in-one analytical systems with built-in sensing capabilities. Current progress for in vivo biosensing and integration into analytical instrumentation towards fully functional devices will be also covered. We hope that this review provides the reader with some general knowledge and future prospects of self-propelled micromachines as a new paradigm in analytical chemistry. Graphical abstract.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas de Química Analítica/métodos , Microtecnologia/métodos , Animais , Técnicas Biossensoriais/instrumentação , Técnicas de Química Analítica/instrumentação , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Desenho de Equipamento , Humanos , Microtecnologia/instrumentação , Nanoestruturas/química , Nanotecnologia/instrumentação , Nanotecnologia/métodos
5.
Nat Protoc ; 14(9): 2707-2747, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31451784

RESUMO

Nitrogen-vacancy (NV) quantum defects in diamond are sensitive detectors of magnetic fields. Owing to their atomic size and optical readout capability, they have been used for magnetic resonance spectroscopy of nanoscale samples on diamond surfaces. Here, we present a protocol for fabricating NV diamond chips and for constructing and operating a simple, low-cost 'quantum diamond spectrometer' for performing NMR and electron spin resonance (ESR) spectroscopy in nanoscale volumes. The instrument is based on a commercially available diamond chip, into which an NV ensemble is ion-implanted at a depth of ~10 nm below the diamond surface. The spectrometer operates at low magnetic fields (~300 G) and requires standard optical and microwave (MW) components for NV spin preparation, manipulation, and readout. We demonstrate the utility of this device for nanoscale proton and fluorine NMR spectroscopy, as well as for the detection of transition metals via relaxometry. We estimate that the full protocol requires 2-3 months to implement, depending on the availability of equipment, diamond substrates, and user experience.


Assuntos
Diamante/química , Espectroscopia de Ressonância de Spin Eletrônica/instrumentação , Espectroscopia de Ressonância Magnética/instrumentação , Nanotecnologia/instrumentação , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Espectroscopia de Ressonância Magnética/métodos , Nanopartículas/química , Processamento de Sinais Assistido por Computador
6.
Adv Mater ; 31(41): e1904448, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31456284

RESUMO

Colloidal crystal engineering with DNA on template-confined surfaces is used to prepare arrays of nanocube-based plasmonic antennas and deliberately place dyes with sub-nm precision into their hotspots, on the DNA bonds that confine the cubes to the underlying gold substrate. This combined top-down and bottom-up approach provides independent control over both the plasmonic gap and photonic lattice modes of the surface-confined particle assemblies and allows for the tuning of the interactions between the excited dyes and plasmonically active antennas. Furthermore, the gap mode of the antennas can be modified in situ by utilizing the solvent-dependent structure of the DNA bonds. This is studied by placing two dyes, with different emission wavelengths, under the nanocubes and recording their solvent-dependent emission. It is shown that dye emission not only depends upon the in-plane structure of the antennas but also the size of the gap, which is regulated with solvent. Importantly, this approach allows for the systematic understanding of the relationship between nanoscale architecture and plasmonically coupled dye emission, and points toward the use of colloidal crystal engineering with DNA to create stimuli responsive architectures, which can find use in chemical sensing and tunable light sources.


Assuntos
DNA/química , Corantes Fluorescentes/química , Nanotecnologia/instrumentação , Nanotubos/química , Espectrometria de Fluorescência
7.
Biosens Bioelectron ; 142: 111573, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31412314

RESUMO

Layered transition metal dichalcogenides (TMDs) are important members in the family of two-dimensional (2D) materials. The large surface-to-volume ratio, combined with the fascinating tunable electronic and optical properties, low toxicity, unique van der Waals layered structure, and engineerable surface structure, renders 2D TMDs highly valuable for next-generation biosensing applications. Herein, the recent progress in the development of 2D TMDs-based biosensors is comprehensively reviewed, with special focus on the implementation of the structural, electronic and optical properties of 2D TMDs in the realization of high-performance biosensors with different configurations for a wide spectrum of bioanalytes and bio-species. In addition, the comparison on biosensing performances with graphene as the currently most studied 2D candidate is critically discussed. Finally, future perspectives are provided along the development progress of 2D TMDs-based biosensors which are currently undergoing an intense study. This work will lead researchers to explore more novel sensing candidates within the category of TMDs with exotic chemical composition, structure, morphologies, dimensionalities, and properties.


Assuntos
Técnicas Biossensoriais/métodos , Metais/química , Nanoestruturas/química , Animais , Técnicas Biossensoriais/instrumentação , Desenho de Equipamento , Grafite/química , Grafite/toxicidade , Humanos , Metais/toxicidade , Nanoestruturas/toxicidade , Nanotecnologia/instrumentação , Nanotecnologia/métodos , Elementos de Transição/química , Elementos de Transição/toxicidade
8.
Biomed Microdevices ; 21(3): 65, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273548

RESUMO

We present an electrolyte-gated graphene field effect transistor (GFET) nanosensor using aptamer for rapid, highly sensitive and specific detection of a lung cancer biomarker interleukin-6 (IL-6) with enhanced stability. The negatively charged aptamer folds into a compact secondary conformation upon binding with IL-6, thus altering the carrier concentration of graphene and yielding a detectable change in the drain-source current Ids. Aptamer has smaller size than other receptors (e.g. antibodies), making it possible to bring the charged IL-6 more closely to the graphene surface upon affinity binding, thereby enhancing the sensitivity of the detection. Thanks to the higher stability of aptamer over antibodies, which degrade easily with increasing storage time, consistent sensing performance was obtained by our nanosensor over extended-time (>24 h) storage at 25 °C. Additionally, due to the GFET-enabled rapid transduction of the affinity recognition to IL-6, detection of IL-6 can be achieved in several minutes (<10 min). Experimental results indicate that this nanosensor can rapidly and specifically respond to the change in IL-6 levels with high consistency after extended-time storage and a detection limit (DL) down to 139 fM. Therefore, our nanosensor holds great potential for lung cancer diagnosis at its early stage.


Assuntos
Aptâmeros de Nucleotídeos/metabolismo , Biomarcadores Tumorais/metabolismo , Técnicas Biossensoriais/instrumentação , Grafite/química , Limite de Detecção , Neoplasias Pulmonares/metabolismo , Nanotecnologia/instrumentação , Aptâmeros de Nucleotídeos/química , Interleucina-6/metabolismo , Propriedades de Superfície , Transistores Eletrônicos
9.
Med Phys ; 46(9): 4233-4240, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31276225

RESUMO

PURPOSE: We developed a new class of aerogel-based thin-film self-powered radiation sensors employing high-energy electron current (HEC) in periodic multilayer (high-Z | polyimide aerogel (PA) | low-Z) electrode microstructures. MATERIALS: Low-Z (Al) and high-Z (Ta) electrodes were deposited on 50 µm-thick PA films to obtain sensors with Al-PA-Ta-PA-Al structures. Sensors were tested with x rays in the 40-120 kVp range and with 2.5 MV, 6 MV, and 6 MV-FFF linac beams (TrueBeam, Varian). Performance of PA-HEC sensors was compared to commercial A12 Farmer ionization chamber as well as to radiation transport simulations using CEPXS/ONEDANT with nanometer-to-micrometer spatial resolution. The computations included periodic and single-element structures N x (Al-PA-Ta-PA-Al) with variable layer thicknesses. RESULTS: Signal from PA-HEC sensors was proportional to the simulated net leakage electron current (averaged over the PA thickness). Experimental response was linear with dose and independent of dose rate. Detector responses to different x-ray sources show higher signals for kVp photon energies, as expected, though a strong signal was obtained for MV energies as well. The signal scaled with total effective area inside the multielemental structures; for example, the yield of a multielement sensor made with 20 Ta layers compared to a single-element structure with 1 Ta layer of the same total thickness of Ta was 10 times greater for 6 MV beam and 23 times greater for 120 kVp. Beam attenuation per element in the detector was 0.5%, 1%, 3%, and 46%, respectively for 6 MV, 6 MV FFF, 2.5 MV, and 120 kVp. CONCLUSION: We demonstrated the feasibility of aerogel-based multilayer HEC radiation detector and its application for flux/dose monitoring of kVp and radiotherapy MV beams with small beam attenuation.


Assuntos
Elétrons , Nanotecnologia/instrumentação , Radiometria/instrumentação , Géis , Porosidade , Fatores de Tempo , Raios X
10.
Phys Chem Chem Phys ; 21(30): 16751-16761, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31322638

RESUMO

In the context of the decisive role that vibronic interactions play in the functioning of molecular quantum cellular automata, in this article we give a comparative analysis of the two alternative vibronic approaches to the evaluation of the key functional characteristics of molecular cells. Semiclassical Born-Oppenheimer approximation and quantum mechanical evaluations of the vibronic energy pattern, electronic density distributions and cell-cell response function are performed for two-electron square-planar mixed valence molecular cells subjected to the action of a molecular driver. Special emphasis is put on the description of the cell-cell response function, which describes strong non-linearity as a prerequisite for the effective action of quantum cellular automata. Comparison of results obtained within the semiclassical and quantum-mechanical approaches has revealed a drastic difference between the shapes of the cell-cell response functions evaluated within these two approaches in the case of moderate vibronic coupling when the energy levels of the square cell interacting with a weakly polarized driver undergo large tunneling splitting in shallow adiabatic potential minima. In contrast, in the limits of strong vibronic coupling (a double-well adiabatic potential with deep minima) and weak vibronic coupling (a single well adiabatic potential) the adiabatic approximation is shown to describe the cell-cell response function with rather good accuracy.


Assuntos
Nanotecnologia/métodos , Teoria Quântica , Nanotecnologia/instrumentação , Vibração
11.
Colloids Surf B Biointerfaces ; 182: 110354, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31325775

RESUMO

Nanoflowers - new nanostructures - have aroused the interest of scientists due to the topographic features of nanolayers, the special location of which allows a higher surface-to-volume ratio compared to classic spherical nanoparticles, which significantly increases the efficiency of surface reactions for nanoflowers. The main purpose of these types of nanomaterials is their use as enzyme stabilizers. To facilitate the functioning of enzymes under different conditions, organic-inorganic hybrid nanomaterials have been developed, the name of which indicates that all components of inorganic nanoparticles are associated with organic materials. These nanoparticles have many promising applications in catalysis, as biosensors, and for drug delivery. Organic-inorganic hybrid nanoflowers have led to the development of a new branch of chemistry - the chemistry of hybrid nanomaterials - in which research is rapidly developing. Thus, studying organic-inorganic hybrid nanocrystals can lead to creative new solutions in the field of chemistry of enzyme systems and the rapid development of bionanomaterials and new biotechnology industries. Present review focuses on wide biomedical applications of nanoflowers including biocatalysis, detection of substances, electrochemical biosensors based on nanoflowers, photosensitizers, drug and gene carriers and detection of various diseases, photothermal and other treatments. It will be interesting for wide range of scientists focusing in topic of new kinds of nanoparticles.


Assuntos
Técnicas Biossensoriais , Estruturas Metalorgânicas/síntese química , Nanomedicina/métodos , Nanoestruturas/química , Nanotecnologia/métodos , Animais , Biocatálise , Sistemas de Liberação de Medicamentos/métodos , Técnicas Eletroquímicas , Humanos , Estruturas Metalorgânicas/ultraestrutura , Nanomedicina/instrumentação , Nanoestruturas/administração & dosagem , Nanoestruturas/ultraestrutura , Nanotecnologia/instrumentação , Tamanho da Partícula , Fármacos Fotossensibilizantes/química , Propriedades de Superfície
12.
Nanoscale ; 11(30): 14099-14112, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31214671

RESUMO

The advent of micro/nanomotors (MNMs) has shed light on the innovation of active biomedical systems or devices that might bring revolutionary solutions to traditional biomedical strategies. In spite of development beyond expectation over the last decade with a fair number of proof-of-concept demonstrations, the in vivo practical application of MNMs for clinical use is still in its infancy. The biocompatibility of MNMs is the first consideration before realizing practicality, taking into account the complicated interactions between the self-propelled MNMs and biological systems. Therefore, in this review, we focused on the biocompatibility of MNMs with regard to the fabrication materials and propulsion mechanisms by means of in-depth discussions on the advantages and limitations of MNMs for operating under physiological conditions. The future prospective and suggestions on the development of MNMs toward practical biomedical applications will also be proposed.


Assuntos
Materiais Biocompatíveis/química , Nanomedicina , Nanoestruturas/química , Nanotecnologia/métodos , Metais/química , Nanotecnologia/instrumentação , Polímeros/química
13.
Genes (Basel) ; 10(6)2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31226847

RESUMO

Genetic markers (DNA barcodes) are often used to support and confirm species identification. Barcode sequences can be generated in the field using portable systems based on the Oxford Nanopore Technologies (ONT) MinION sequencer. However, to achieve a broader application, current proof-of-principle workflows for on-site barcoding analysis must be standardized to ensure a reliable and robust performance under suboptimal field conditions without increasing costs. Here, we demonstrate the implementation of a new on-site workflow for DNA extraction, PCR-based barcoding, and the generation of consensus sequences. The portable laboratory features inexpensive instruments that can be carried as hand luggage and uses standard molecular biology protocols and reagents that tolerate adverse environmental conditions. Barcodes are sequenced using MinION technology and analyzed with ONTrack, an original de novo assembly pipeline that requires as few as 1000 reads per sample. ONTrack-derived consensus barcodes have a high accuracy, ranging from 99.8 to 100%, despite the presence of homopolymer runs. The ONTrack pipeline has a user-friendly interface and returns consensus sequences in minutes. The remarkable accuracy and low computational demand of the ONTrack pipeline, together with the inexpensive equipment and simple protocols, make the proposed workflow particularly suitable for tracking species under field conditions.


Assuntos
Biodiversidade , Código de Barras de DNA Taxonômico/instrumentação , Sequenciamento de Nucleotídeos em Larga Escala/instrumentação , Nanotecnologia/instrumentação , Nanoporos , Análise de Sequência de DNA/instrumentação , Fluxo de Trabalho
14.
J Pharm Biomed Anal ; 174: 206-213, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31176930

RESUMO

Highly sensitive nanosensors such as graphene oxide/ platinum-iridium nanohybrid, carboxylic acid functionalized multiwalled carbon nanotubes (GO/Pt-Ir/MWCNT-COOH) and amine functionalized multiwalled carbon nanotubes (GO/Pt-Ir/MWCNT-NH2) modified glassy carbon electrode were developed for the determination of 5-hydroxytryptamine receptor agonist, Eletriptan. Graphene oxide/platinum-iridium nanohybrid was synthesized using sonication method and then characterized by spectroscopic and microscopic methods such as Raman, TEM, HRTEM, XPS, and XRD. The prepared nanohybrids modified on glassy carbon electrodes were well characterized and applied for electrochemical determination of Eletriptan. The significant enhancement of the oxidation peak current of Eletriptan was observed in GO/Pt-Ir/MWCNT-COOH as a best nanosensor in all prepared ones. The pH, scan rate and the amount of GO/Pt-Ir/MWCNT-COOH were also optimized for Eletriptan analysis. After obtaining of the optimum conditions, the identification of Eletriptan was performed between the linear range of 1 × 10-7 M and 4 × 10-6 M with a detection limit of 6.1 × 10-9 M. The developed method was successfully applied for the determination of the drug in tablets with acceptable recoveries. Moreover, it can be elicited that, in electrochemical studies, electroactive interferences from the tablet excipients did not interfere with the results.


Assuntos
Nanotecnologia/instrumentação , Pirrolidinas/análise , Agonistas do Receptor de Serotonina/análise , Triptaminas/análise , Formas de Dosagem , Eletrodos , Grafite/química , Concentração de Íons de Hidrogênio , Irídio/química , Limite de Detecção , Modelos Lineares , Nanotubos de Carbono/química , Platina/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Difração de Raios X
15.
Biosensors (Basel) ; 9(2)2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31185689

RESUMO

The localized surface plasmon resonance (LSPR) property of metallic nanoparticles is widely exploited for chemical and biological sensing. Selective biosensing of molecules using functionalized nanoparticles has become a major research interdisciplinary area between chemistry, biology and material science. Noble metals, especially gold (Au) and silver (Ag) nanoparticles, exhibit unique and tunable plasmonic properties; the control over these metal nanostructures size and shape allows manipulating their LSPR and their response to the local environment. In this review, we will focus on Ag-based nanoparticles, a metal that has probably played the most important role in the development of the latest plasmonic applications, owing to its unique properties. We will first browse the methods for AgNPs synthesis allowing for controlled size, uniformity and shape. Ag-based biosensing is often performed with coated particles; therefore, in a second part, we will explore various coating strategies (organics, polymers, and inorganics) and their influence on coated-AgNPs properties. The third part will be devoted to the combination of gold and silver for plasmonic biosensing, in particular the use of mixed Ag and AuNPs, i.e., AgAu alloys or Ag-Au core@shell nanoparticles will be outlined. In the last part, selected examples of Ag and AgAu-based plasmonic biosensors will be presented.


Assuntos
Nanopartículas Metálicas/química , Prata/química , Ressonância de Plasmônio de Superfície/métodos , Ligas/química , Animais , Desenho de Equipamento , Ouro/química , Humanos , Nanopartículas Metálicas/ultraestrutura , Nanotecnologia/instrumentação , Nanotecnologia/métodos , Ressonância de Plasmônio de Superfície/instrumentação
16.
Biomed Eng Online ; 18(1): 73, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31185982

RESUMO

BACKGROUND: Patients with end-stage renal disease (ESRD) have failed kidney function, and often must be treated with hemodialysis to extend the patient's life by artificially removing excess fluid and toxins from the blood. However, life-threatening treatment complications can occur because hemodialysis protocols are adjusted infrequently, as opposed to the kidneys which filter blood continuously. Infrequent blood tests, about once per month on average, are used to adjust hemodialysis protocols and as a result, patients can experience electrolyte imbalances, which can contribute to premature patient deaths from treatment complications, such as sudden cardiac death. Since hemodialysis can lead to blood loss, drawing additional blood for tests to assess the patient's kidney function and blood markers is limited. However, sampling multiple drops of blood per session using a microfluidic device has the potential to reduce not only the amount of blood drawn and avoid unnecessary venipuncture, but also reduce costs by limiting medical complications of hemodialysis and provide a more comprehensive assessment of the patient's health status in real time. RESULT: We present preliminary proof-of-concept results of a microfluidic device which uses DNA-based fluorescence nanosensors to measure potassium concentration in a flowing solution. In a matter of minutes, the flowing potassium solution reduced the fluorescence intensity of the nanosensors to a steady-state value. CONCLUSIONS: These proof-of-concept results demonstrate the ability of our DNA-based nanosensors to measure potassium concentration in a microfluidic device. The long-term goal is to integrate this technology with a device to measure potassium and eventually other blood contents multiple times throughout a hemodialysis session, enabling protocol adjustment similar to a healthy kidney.


Assuntos
Técnicas Biossensoriais/instrumentação , DNA/metabolismo , Dispositivos Lab-On-A-Chip , Nanotecnologia/instrumentação , Potássio/análise , Diálise Renal
17.
Biosens Bioelectron ; 141: 111384, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31195196

RESUMO

The purpose of the current review article is to present a comprehensive understanding regarding pros and cons of graphene related nanocomposites and to find ways in order to improve the performance of nanocomposites with new designs. Nanomaterials including GR are employed in industrial applications such as supercapacitors, biosensors, solar cells, and corrosion studies. The present article has been prepared in three main categories. In the first part, graphene types have been presented, as pristine graphene, graphene oxide and reduced graphene oxide. In the second part, nanocomposites with many graphene, inorganic and polymeric materials such as polymer/GR, activated carbon/GR, metal oxide/GR, metal/graphene and carbon fibre/GR have been investigated in more detail. In the third part, the focus in on the industrial applications of GR nanocomposite, including super capacitors, biosensors, solar cells, and corrosion protection studies.


Assuntos
Técnicas Biossensoriais/métodos , Grafite/química , Nanocompostos/química , Nanotecnologia/métodos , Polímeros/química , Animais , Técnicas Biossensoriais/instrumentação , Humanos , Modelos Moleculares , Nanocompostos/ultraestrutura , Nanotecnologia/instrumentação
18.
Biosens Bioelectron ; 141: 111417, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31202187

RESUMO

Fascinating properties of ZnO nanostructures have created much interest due to their importance in health care and environmental monitoring. Current worldwide production and their wide range of applications signify ZnO to be a representative of multi-functional oxide material. Recent nanotechnological developments have stimulated the production of various forms of ZnO nanostructures such as nano-layers, nanoparticles, nanowires, etc. Due to their enhanced sensing properties, improved binding ability with biomolecules as well as biological activities have enabled them as suitable candidates for the fabrication of biosensor devices in the biomedical arena. In this review, the synthesis of ZnO nanostructures, mechanism of their interaction with biomolecules and their applications as sensors in health care area are discussed considering the biosensors for molecules with small molecular weight, infectious diseases, and pharmaceutical compounds.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Nanoestruturas/química , Óxido de Zinco/química , Animais , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Eletrodos , Desenho de Equipamento , Humanos , Nanoestruturas/ultraestrutura , Nanotecnologia/instrumentação , Nanotecnologia/métodos
19.
Chem Commun (Camb) ; 55(50): 7203-7206, 2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-31165120

RESUMO

Failure of autophagy induction results in the accumulation of abnormal mitochondria to cause neurodegenerative diseases. Artificial autophagy activation via the mitochondrial delivery of polyrotaxane with autophagy induced activity is achieved using a MITO-Porter, a nanodevice for mitochondrial delivery. This strategy can be applied to innovative research and therapy.


Assuntos
Autofagia/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Nanotecnologia/instrumentação , Rotaxanos/química , beta-Ciclodextrinas/farmacologia , Células HeLa , Humanos , Metilação , beta-Ciclodextrinas/química
20.
Biosens Bioelectron ; 141: 111434, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31238281

RESUMO

The pragmatic outcome of a lung cancer diagnosis is closely interrelated in reducing the number of fatal death caused by the world's top cancerous disease. Regardless of the advancement made in understanding lung tumor, and its multimodal treatment, in general the percentage of survival remain low. Late diagnosis of a cancerous cell in patients is the major hurdle for the above circumstances. In the new era of a lung cancer diagnosis with low cost, portable and non-invasive clinical sampling, nanotechnology is at its inflection point where current researches focus on the implementation of biosensor conjugated nanomaterials for the generation of the ideal sensing. The present review encloses the superiority of nanomaterials from zero to three-dimensional nanostructures in its discrete and nanocomposites nanotopography on sensing lung cancer biomarkers. Recent researches conducted on definitive nanomaterials and nanocomposites at multiple dimension with distinctive physiochemical property were focused to subside the cases associated with lung cancer through the development of novel biosensors. The hurdles encountered in the recent research and future preference with prognostic clinical lung cancer diagnosis using multidimensional nanomaterials and its composites are presented.


Assuntos
Técnicas Biossensoriais/métodos , Neoplasias Pulmonares/diagnóstico , Nanoestruturas/química , Animais , Biomarcadores Tumorais/análise , Técnicas Biossensoriais/instrumentação , Humanos , Nanomedicina/instrumentação , Nanomedicina/métodos , Nanoestruturas/ultraestrutura , Nanotecnologia/instrumentação , Nanotecnologia/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA