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1.
J Colloid Interface Sci ; 581(Pt A): 21-30, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32768732

RESUMO

Lanthanide ion (Ln3+)-doped nanoscale hydroxyapatites (nHAp) with tunable luminescence have attracted increasing attention due to their potential applications as useful biomedical tools (e.g., imaging and clinical therapy). In this study, we reported that doping Terbium (III) ions (Tb3+) in self-activated luminescent nHAp via a facile hydrothermal reaction, using trisodium citrate (Cit3-), generates unique emission-tunable probes known as Cit/Tb-nHAp. The morphology, crystal phase, and luminescence properties of these Cit/Tb-nHAp probes are studied in detail. Moreover, the results demonstrate that the luminescence of self-activated nHAp originates from the carbon dots trapped within the nHAp crystals, in which partial energy transfer occurs from carbon dots (CDs) to Tb3+. The color tunability is successfully achieved by regulating the addition of Cit3-. Biocompatibility study indicates that when co-cultured with C6 glioma cells in vitro for 3 days, ≤800 ppm Cit/Tb-nHAp is not cytotoxic for C6 glioma cells. We also present in vitro data showing efficient cytoplasmic localization of transferrin conjugated Cit/Tb-nHAp into C6 glioma cells by fluorescence cell imaging. We have successfully engineered Cit/Tb-nHAp, a promising biocompatible agent for future in vitro and in vivo fluorescence bioimaging.

2.
Sci Rep ; 10(1): 18636, 2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-33122804

RESUMO

This study was performed to investigate the Eustachian tube as a potential route for contralateral spreading following intratympanic nanoparticle (NP)-conjugated gentamicin injection in a rat model. Sprague-Dawley rats were divided into three groups and substances were injected in the right ear: group 1 (fluorescent magnetic nanoparticles [F-MNPs], n = 4), group 2 (F-MNP-conjugated gentamicin [F-MNP@GM], n = 2), and control group (no injections, n = 2). T2-weighted sequences corresponding to the regions of interest at 1, 2, and 3 h after intratympanic injection were evaluated, along with immunostaining fluorescence of both side cochlea. The heterogeneous signal intensity of F-MNPs and F-MNP@GM on T2-weighted images, observed in the ipsilateral tympanum, was also detected in the contralateral tympanum in 4 out of 6 rats, recapitulating fluorescent nanoparticles in the contralateral cochlear hair cells. Computational simulations demonstrate the contralateral spreading of particles by gravity force following intratympanic injection in a rat model. The diffusion rate of the contralateral spreading relies on the sizes and surface charges of particles. Collectively, the Eustachian tube could be a route for contralateral spreading following intratympanic injection. Caution should be taken when using the contralateral ear as a control study investigating inner-ear drug delivery through the transtympanic approach.

3.
Nanoscale ; 2020 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-32239078

RESUMO

Control of the chemical and physical properties of nanoscale colloids and their nanoassemblies remains a challenging issue for enhancing the performance and functionalities of nanodevices. In this study, we report a post-synthesis etching method to tailor the porosity of the Fe3O4 shells coating on Ag NPs, establishing a facile but effective approach to regulate the chemical and optical properties of the colloids and their assembled structures. As the shell porosity increases, the NPs are transformed, producing enhanced catalytic activity and the surface-enhanced Raman spectroscopy (SERS) effect, which results from enhanced chemical diffusion into the Ag core. Magnetoplasmonic (MagPlas) one- (1D) and two- (2D) dimensional arrays fabricated using these porosity-controllable NPs exhibit intriguing plasmon properties that are strongly affected by the porosity of the particle shell. Furthermore, the bright coloration of the 2D arrays is tuned by changing the shell porosity or introducing an additional metallic layer. Such 1D and 2D porous MagPlas metastructures possessing Fe3O4 shells with tunable porosities are a fulcrum for developing recyclable catalysts and tunable optical filters with optimized activity, selectivity, and sensitivity, as well as color displays and sensing platforms.

4.
Artigo em Inglês | MEDLINE | ID: mdl-32181632

RESUMO

One-dimensional nanostructures with controllable aspect ratios are essential for a wide range of applications. An approach for magnetic superparticle (SP) assembly over large areas (55 mm × 25 mm) is introduced via co-assistance of electrostatic and magnetic fields, so-called magnetic layer-by-layer assembly, on an arbitrary hydrophilic substrate within minutes. The SP structures [diameter (d) = 120-350 nm] of Fe3O4 or Ag@Fe3O4 composites composed of hundreds of magnetite nanocrystals (d = 10-20 nm) are used as colloidal monomers to fabricate arrays of high aspect ratio (up to 102) linear nanochains, viz. colloidal polymers, where thermal disturbances were minimized. The arrays of colloidal polymers exhibit strong optical polarization effects owing to their geometrical anisotropy, which can be used as a simple optical filter. Furthermore, by using the binary colloidal mixture of different magnetic colloids, including different sized Fe3O4 and magnetoplasmonic Ag@Fe3O4, low aspect ratio (2-15) colloidal chains, viz. magnetic/plasmonic oligomers, with tunable lengths were fabricated, affording a facile but an effective approach to modulate the optical properties of the chains. The scalable fabrication of well-aligned, linear colloidal polymers and oligomers opens up appealing opportunities for the development of sensors, subwavelength waveguides, optical tweezers, and enhanced solar harvesting devices.

5.
Colloids Surf B Biointerfaces ; 189: 110839, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32036333

RESUMO

From senescence and frailty that may result from various biological, mechanical, nutritional, and metabolic processes, the human body has its own antioxidant defense enzymes to remove by-products of oxygen metabolism, and if unregulated, can cause several types of cell damage. Herein, an antioxidant, artificial nanoscale enzyme, called nanozyme (NZs), is introduced that is composed of Au nanoparticles (NPs) synthesized with a mixture of two representative phytochemicals, namely, gallic acid (GA) and isoflavone (IF), referred to as GI-Au NZs. Their unique antioxidant and anti-aging effects are monitored using Cell Counting Kit-8 and senescence-associated ß-galactosidase assays on neonatal human dermal fibroblasts (nHDFs). Furthermore, alterations in epidermal thickness and SOD activity are measured under ultraviolet light to investigate the effects of the topical application of NZs on the histological structure and antioxidant activity in hairless mice skin. Then, hepatotoxicity and nephrotoxicity in the hairless mice are monitored. It is concluded that the NZs can effectively prevent serial passage-induced senescence in nHDFs, as well as oxidative stress in mice skin, suggesting a range of strategies to further develop novel therapeutics for acute frailty.

7.
ACS Appl Mater Interfaces ; 10(49): 41935-41946, 2018 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-30465605

RESUMO

Magnetic nanoparticles have had a significant impact on a wide range of advanced applications in the academic and industrial fields. In particular, in nanomedicine, the nanoparticles require specific properties, including hydrophilic behavior, uniform and tunable dimensions, and good magnetic properties, which are still challenging to achieve by industrial-scale synthesis. Here, we report a gram-scale synthesis of hydrophilic magnetic nanoclusters based on a one-pot solvothermal system. Using this approach, we achieved the nanoclusters with controlled size composed of magnetite nanocrystals in close-packed superstructures that exhibited hydrophilicity, superparamagnetism, high magnetization, and colloidal stability. The proposed solvothermal method is found to be highly suitable for synthesizing industrial quantities (gram-per-batch level) of magnetic spheres with unchanged structural and magnetic properties. Furthermore, coating the magnetic spheres with an additional silica layer provided further stability and specific functionalities favorable for biological applications. Using in vitro and in vivo studies, we successfully demonstrated both positive and negative separation and the use of the magnetic nanoclusters as a theragnostic nanoprobe. This scalable synthetic procedure is expected to be highly suitable for widespread use in biomedical, energy storage, photonics, and catalysis fields, among others.


Assuntos
Nanopartículas de Magnetita/química , Nanopartículas/química , Dióxido de Silício/química , Nanomedicina Teranóstica , Coloides/química
8.
Opt Lett ; 43(21): 5476-5479, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30383038

RESUMO

We demonstrate a real-time surface plasmon resonance imaging (SPRi) system based on a wavelength-swept laser. Compared to conventional spectral-modulation SPRi using white light source and spectral filtering, the proposed system has a higher scan rate to detect rapid changes in refractive index and a higher output power for large-area illumination. This SPRi system achieves scan rates faster than 12 Hz, simultaneously obtaining SPR dip positions over full illumination fields of 12×12 mm. Using the wavelength-swept laser, two-dimensional biomolecular array imaging can be acquired with a high dynamic detection range (7.67×10-3 refractive index unit (RIU)) as well as high sensitivity (6501 nm/RIU) and resolution (1.89×10-6 RIU).

9.
ACS Appl Mater Interfaces ; 10(15): 12534-12543, 2018 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-29595253

RESUMO

Rapid and sensitive detection of influenza virus is of soaring importance to prevent further spread of infections and adequate clinical treatment. Herein, an ultrasensitive colorimetric assay called magnetic nano(e)zyme-linked immunosorbent assay (MagLISA) is suggested, in which silica-shelled magnetic nanobeads (MagNBs) and gold nanoparticles are combined to monitor influenza A virus up to femtogram per milliliter concentration. Two essential strategies for ultrasensitive sensing are designed, i.e., facile target separation by MagNBs and signal amplification by the enzymelike activity of gold nanozymes (AuNZs). The enzymelike activity was experimentally and computationally evaluated, where the catalyticity of AuNZ was tremendously stronger than that of normal biological enzymes. In the spiked test, a straightforward linearity was presented in the range of 5.0 × 10-15-5.0 × 10-6g·mL-1 in detecting the influenza virus A (New Caledonia/20/1999) (H1N1). The detection limit is up to 5.0 × 10-12 g·mL-1 only by human eyes, as well as up to 44.2 × 10-15 g·mL-1 by a microplate reader, which is the lowest record to monitor influenza virus using enzyme-linked immunosorbent assay-based technology as far as we know. Clinically isolated human serum samples were successfully observed at the detection limit of 2.6 PFU·mL-1. This novel MagLISA demonstrates, therefore, a robust sensing platform possessing the advances of fathomable sample separation, enrichment, ultrasensitive readout, and anti-interference ability may reduce the spread of influenza virus and provide immediate clinical treatment.


Assuntos
Imunoadsorventes/química , Ensaio de Imunoadsorção Enzimática , Ouro , Humanos , Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A , Nanopartículas Metálicas
11.
Regen Biomater ; 4(3): 159-166, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28740639

RESUMO

In recent years, much research has been suggested and examined for the development of tissue engineering scaffolds to promote cellular behaviors. In our study, RGD peptide and graphene oxide (GO) co-functionalized poly(lactide-co-glycolide, PLGA) (RGD-GO-PLGA) nanofiber mats were fabricated via electrospinning, and their physicochemical and thermal properties were characterized to explore their potential as biofunctional scaffolds for vascular tissue engineering. Scanning electron microscopy images revealed that the RGD-GO-PLGA nanofiber mats were readily fabricated and composed of random-oriented electrospun nanofibers with average diameter of 558 nm. The successful co-functionalization of RGD peptide and GO into the PLGA nanofibers was confirmed by Fourier-transform infrared spectroscopic analysis. Moreover, the surface hydrophilicity of the nanofiber mats was markedly increased by co-functionalizing with RGD peptide and GO. It was found that the mats were thermally stable under the cell culture condition. Furthermore, the initial attachment and proliferation of primarily cultured vascular smooth muscle cells (VSMCs) on the RGD-GO-PLGA nanofiber mats were evaluated. It was revealed that the RGD-GO-PLGA nanofiber mats can effectively promote the growth of VSMCs. In conclusion, our findings suggest that the RGD-GO-PLGA nanofiber mats can be promising candidates for tissue engineering scaffolds effective for the regeneration of vascular smooth muscle.

12.
J Microbiol Biotechnol ; 27(8): 1483-1490, 2017 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-28595381

RESUMO

In this study, silver nanoparticles (AgNPs) were synthesized by the citrate reduction process and, with the assistance of n-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, were successfully loaded with the macromolecular drug vancomycin (VAM) to form AgNP-VAM bioconjugates. The synthesized AgNPs, VAM, and AgNP-VAM conjugate were characterized by UV-visible spectroscopy, zeta potential analysis, confocal microscopy, and transmission electron microscopy. The effect of loading VAM onto AgNPs was investigated by testing the internalization of the bioconjugate into Mycobacterium smegmatis. After treatment with the AgNP-VAM conjugate, the bacterial cells showed a significant decrease in UV absorption, indicating that loading of the VAM on AgNPs had vastly improved the drug's internalization compared with that of AgNPs. All the experimental assessments showed that, compared with free AgNPs and VAM, enhanced internalization had been successfully achieved with the AgNP-VAM conjugate, thus leading to significantly better delivery of the macromolecular drug into the M. smegmatis cell. The current research provides a new potential drug delivery system for the treatment of mycobacterial infections..


Assuntos
Antituberculosos/metabolismo , Portadores de Fármacos/metabolismo , Endocitose , Mycobacterium smegmatis/metabolismo , Nanopartículas/metabolismo , Prata/metabolismo , Vancomicina/metabolismo , Sistemas de Liberação de Medicamentos
13.
Biosens Bioelectron ; 96: 68-76, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28463738

RESUMO

Tuberculosis (TB) is an often neglected, epidemic disease that remains to be controlled by contemporary techniques of medicine and biotechnology. In this study, a nanoscale sensing system, referred to as magnetophoretic immunoassay (MPI) was designed to capture culture filtrate protein (CFP)-10 antigens effectively using two different types of nanoparticles (NPs). Two specific monoclonal antibodies against CFP-10 antigen were used, including gold NPs for signaling and magnetic particles for separation. These results were carefully compared with those obtained using the commercial mycobacteria growth indicator tube (MGIT) test via 2 sequential clinical tests (with ca. 260 clinical samples). The sensing linearity of MPI was shown in the range of pico- to micromoles and the detection limit was 0.3pM. MPI using clinical samples shows robust and reliable sensing while monitoring Mycobacterium tuberculosis (MTB) growth with monitoring time 3-10 days) comparable to that with the MGIT test. Furthermore, MPI distinguished false-positive samples from MGIT-positive samples, probably containing non-tuberculous mycobacteria. Thus, MPI shows promise in early TB diagnosis.


Assuntos
Imunoensaio/métodos , Nanopartículas Metálicas/química , Mycobacterium tuberculosis/isolamento & purificação , Anticorpos Monoclonais/química , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Técnicas Bacteriológicas/métodos , Técnicas Biossensoriais/métodos , Óxido Ferroso-Férrico/química , Ouro/química , Humanos , Limite de Detecção , Magnetismo , Mycobacterium tuberculosis/crescimento & desenvolvimento , Micobactérias não Tuberculosas/crescimento & desenvolvimento , Micobactérias não Tuberculosas/isolamento & purificação , Tamanho da Partícula , Propriedades de Superfície
14.
J Colloid Interface Sci ; 499: 54-61, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28363104

RESUMO

Preparation of suprastructure assemblies with unique colloidal and optical properties remains challenging. Non-uniform covering of magnetic nanoparticles (NPs) with an external inert Au shell has been attempted to protect the magnetic core against oxidation as well as to produce multifunctional supraparticles (SPs) possessing respective optical and magnetic properties. In this study, a concave Au NP coating was deposited on magnetic nanoparticles (MNPs) with precise control of the shell thickness and roughness through a layer-by-layer (LbL) assisted ionic reduction method termed ion-reducible LbL (IR-LbL) method. Surface enhanced Raman spectra were obtained using graphene quantum dots (GQDs) on the magnetically aligned structure of the prepared core-shell SPs. It is probable that this synthesis method and the generated SPs are essential for characterizing the merge of electronics and magnetism in the nano-regime and may be applicable for further electronics, magnetic storage, and biomedical applications.

15.
Sci Rep ; 7: 44495, 2017 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-28290527

RESUMO

Nanomaterials without chemical linkers or physical interactions that reside on a two-dimensional surface are attractive because of their electronic, optical and catalytic properties. An in situ method has been developed to fabricate gold nanoparticle (Au NP) films on different substrates, regardless of whether they are hydrophilic or hydrophobic surfaces, including glass, 96-well polystyrene plates, and polydimethylsiloxane (PDMS). A mixture of sodium formate (HCOONa) and chloroauric acid (HAuCl4) solution was used to prepare Au NP films at room temperature. An experimental study of the mechanism revealed that film formation is dependent on surface wettability and inter particle attraction. The as-fabricated Au NP films were further applied to the colorimetric detection of influenza virus. The response to the commercial target, New Caledonia/H1N1/1999 influenza virus, was linear in the range from 10 pg/ml to 10 µg/ml and limit of detection was 50.5 pg/ml. In the presence of clinically isolated influenza A virus (H3N2), the optical density of developed color was dependent on the virus concentration (10-50,000 PFU/ml). The limit of detection of this study was 24.3 PFU/ml, a limit 116 times lower than that of conventional ELISA (2824.3 PFU/ml). The sensitivity was also 500 times greater than that of commercial immunochromatography kits.


Assuntos
Técnicas Biossensoriais , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/diagnóstico , Ouro/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H3N2/patogenicidade , Influenza Humana/virologia , Nanopartículas Metálicas/química
16.
J Biomed Mater Res A ; 105(6): 1637-1645, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28032681

RESUMO

Chitosan, produced from chitin, is one of the polymers with promising applications in various fields. However, despite diverse research studies conducted on its biocompatibility, its uses are still limited. The main reason is the degree of deacetylation (DOD), which represents the proportion of deacetylated units in the polymer and is directly correlated with its biocompatibility property. In this article, the in vivo biocompatibility of three chitosan-hydroxyapatite composite films composed of chitosan with different DOD values was investigated by traditional biological protocols and novel optical spectroscopic analyses. The DOD of the chitosan obtained from three different manufacturers was estimated and calculated by Raman spectroscopy, Fourier transform infrared spectroscopy, and proton nuclear magnetic resonance spectroscopy. The chitosan with the higher DOD induced a higher incidence of inflammation in skin cells. The amino group density, biodegradability, and crystallinity of chitosan are the three possible factors that need to be considered when determining the biocompatibility of the films for in vivo application, as they led to complicated biological results, resulting in either better or worse inflammation even when using chitosan products with the same DOD. This basic study on the relationship between the DOD and inflammation is valuable for the development of further chitosan-based researches. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1637-1645, 2017.


Assuntos
Materiais Biocompatíveis/efeitos adversos , Materiais Biocompatíveis/química , Quitosana/efeitos adversos , Quitosana/química , Durapatita/efeitos adversos , Durapatita/química , Inflamação/induzido quimicamente , Acetilação , Animais , Inflamação/patologia , Espectroscopia de Ressonância Magnética , Masculino , Ratos Sprague-Dawley , Pele/efeitos dos fármacos , Pele/patologia , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Tecidos Suporte/efeitos adversos , Tecidos Suporte/química
17.
Oncotarget ; 8(3): 5092-5110, 2017 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-27974707

RESUMO

Cancer upregulated gene 2 (CUG2) enhances cell migration and invasion, but the underlying mechanism has not been revealed. Herein, CUG2 decreased the expression of E-cadherin and increased the expression of N-cadherin and vimentin, characteristics of the epithelial-mesenchymal transition (EMT). A CUG2 deletion mutant, lacking interaction with nucleophosmin 1 (NPM1), or suppression of NPM1 reduced wound healing and cell invasion, indicating that CUG2-mediated EMT requires NPM1. CUG2 enhanced activation of Smad2/3 and expression of Snail and Twist, while the CUG2 silence decreased these TGF-ß signaling pathways, leading to suppression of EMT. NPM silence also inhibited the CUG2-induced TGF-ß signaling. These results suggest that TGF-ß signaling is involved in CUG2-induced EMT. Treatment with EW-7197, a novel inhibitor of TGF-ß signaling, diminished CUG2-mediated EMT and inhibition of Akt, ERK, JNK, and p38 MAPK, non-canonical TGF-ß signaling molecules, also decreased expression of Smad2/3, Snail and Twist, leading to inhibition of EMT. The results confirm that TGF-ß signaling is essential for CUG2-mediated EMT. Interestingly, TGF-ß enhanced CUG2 expression. We further found that both CUG2-induced TGF-ß production and TGF-ß-induced CUG2 up-regulation required a physical interaction between Sp1 and Smad2/3 in the CUG2 and TGF-ß promoter, as demonstrated by a promoter reporter assay, immunoprecipitation, and ChIP assay. These results indicated close crosstalk between CUG2 and TGF-ß. Conversely, suppression of CUG2 or NPM1 did not completely inhibit TGF-ß-induced EMT, indicating that the effect of TGF-ß on EMT is dominant over the effect of CUG2 on EMT. Collectively, our findings suggest that CUG2 induces the EMT via TGF-ß signaling.


Assuntos
Proteínas Cromossômicas não Histona/genética , Transição Epitelial-Mesenquimal , Neoplasias Pulmonares/genética , Fator de Crescimento Transformador beta/metabolismo , Células A549 , Caderinas/metabolismo , Linhagem Celular Tumoral , Proteínas Cromossômicas não Histona/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/metabolismo , Transdução de Sinais , Vimentina/metabolismo
18.
ACS Appl Mater Interfaces ; 8(36): 23489-97, 2016 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-27548010

RESUMO

Tuberculosis (TB) remains a relevant infectious disease in the 21st century, and its extermination is still far from being attained. Due to the extreme infectivity of incipient TB patients, a rapid sensing system for proficient point-of-care (POC) diagnostics is required. In our study, a plastic-chip-based magnetophoretic immunoassay (pcMPI) is introduced using magnetic and gold nanoparticles (NPs) modified with Mycobacterium tuberculosis (MTB) antibodies. This pcMPI offers an ultrasensitive limit of detection (LOD) of 1.8 pg·ml(-1) for the detection of CFP-10, an MTB-secreted antigen, as a potential TB biomarker with high specificity. In addition, by combining the plastic chip with an automated spectrophotometer setup, advantages include ease of operation, rapid time to results (1 h), and cost-effectiveness. Furthermore, the pcMPI results using clinical sputum culture filtrate samples are competitively compared with and integrated with clinical data collected from conventional tools such as the acid-fast bacilli (AFB) test, mycobacteria growth indicator tube (MGIT), polymerase chain reaction (PCR), and physiological results. CFP-10 concentrations were consistently higher in patients diagnosed with MTB infection than those seen in patients infected with nontuberculosis mycobacteria (NTM) (P < 0.05), and this novel test can distinguish MTB and NTM while MGIT cannot. All these results indicate that this pcMPI has the potential to become a new commercial TB diagnostic POC platform in view of its sensitivity, portability, and affordability.


Assuntos
Tuberculose , Ouro , Humanos , Imunoensaio , Nanopartículas Metálicas , Mycobacterium tuberculosis , Plásticos , Sistemas Automatizados de Assistência Junto ao Leito
19.
Biosens Bioelectron ; 85: 503-508, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27209577

RESUMO

Multifunctional nanohybrids have created new and valuable opportunities for a wide range of catalysis and biotechnology applications. Here, we present a relatively simple method for producing nanohybrids composed of gold nanoparticles (Au NPs) and carbon nanotubes (CNTs) that does not require an acidic pre-treatment of the CNTs. Transmission electron microscopy (TEM) images and ultraviolet-visible (UV-vis) spectra revealed that Au NPs bonded to the CNT surface. Surface-enhanced Raman scattering (SERS) revealed a stronger signal from Au-CNT nanohybrids than from pristine CNTs. The Au-CNT nanohybrids showed catalytic activity in the oxidation of 3, 3', 5, 5'-tetramethyl-benzidine (TMB) by H2O2 and developed a unique blue colour in aqueous solution. Because of the enhanced peroxidase-like activity of these Au-CNT nanohybrids, they were selected for use as part of a highly sensitive colorimetric test for influenza virus A (H3N2). In the presence of influenza A virus (H3N2) in the test system (specific antibody-conjugated Au CNT nanohybrids-TMB-H2O2), a deep blue colour developed, the optical density of which was dependent on the virus concentration (10-50,000 PFU/ml). The limit of detection of this proposed method was 3.4 PFU/ml, a limit 385 times lower than that of conventional ELISA (1312 PFU/ml). The sensitivity of this test was also 500 times greater than that of commercial immunochromatography kits. The nanohybrid preparation and colorimetric detection methods reported herein may be easily adapted to other nanohybrid structures with enzyme mimetic properties for broader applications in catalysis and nanobiotechnology.


Assuntos
Técnicas Biossensoriais/métodos , Ouro/química , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/sangue , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Anticorpos Imobilizados/química , Benzidinas/química , Catálise , Colorimetria/métodos , Humanos , Peróxido de Hidrogênio/química , Influenza Humana/diagnóstico , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Peroxidase/química , Análise Espectral Raman/métodos
20.
Biotechnol Bioeng ; 113(10): 2298-303, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27002303

RESUMO

A modified enzyme-linked immunosorbent assay (ELISA) with nanomaterials is an effective and powerful method to amplify the signal and reduce the cost of detecting and measuring trace biomarkers or proteins. In this study, an ultra-sensitive colorimetric immunoassay was designed, and its ability to detect influenza viruses using positively charged gold nanoparticles ((+)Au NPs) was assessed as a possible role for peroxidase-mimic inorganic enzymes. This method detected influenza virus A (H1N1) with a linear range up to 10 pg mL(-1) and clinically isolated influenza virus A (H3N2) up to 10 plaque forming units (PFU) mL(-1) , where its sensitivity improved to 500-fold higher than that of commercial virus kits. The sensitivity of this proposed method was not declined even though in complex biological media in compared to conventional ELISA. These results revealed that the (+)AuNP-based colorimetric immunoassay could be suitable for lab-on-a-chip device and open new opportunities for clinical protein diagnostics. Biotechnol. Bioeng. 2016;113: 2298-2303. © 2016 Wiley Periodicals, Inc.


Assuntos
Colorimetria/instrumentação , Ouro/química , Peróxido de Hidrogênio/química , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Nanopartículas Metálicas/química , Peroxidase/química , Benzidinas/química , Técnicas Biossensoriais/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Vírus da Influenza A Subtipo H3N2/imunologia , Peroxidase/imunologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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