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1.
Ecotoxicol Environ Saf ; 196: 110487, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32229327

RESUMO

Despite numerous investigations into AgNP-induced toxicity, little has been taken into consideration the potential health impacts of aged AgNPs in comparison to fresh AgNPs. In the current study, we scrutinized the potential effects of aged AgNPs in animals. We first found that AgNPs underwent morphological transformations after natural ageing in aqueous solution upon exposure to air and sunlight for 9 days, as characterized by significant aggregation with increase of particle size approximately by 2 fold. Meanwhile, dissolved Ag ions from aged AgNPs increased by 33% compared to fresh AgNPs. Strikingly, the acute exposure results showed that aged AgNPs induced lower toxicity in mice relative to fresh AgNPs. Aged AgNPs caused milder local inflammation in the peritoneal cavity of mice, as evidenced by 63% reduction of tumor necrosis factor α (TNF-α) than that induced by fresh AgNPs. The deposition mass of aged AgNPs in the liver, spleen, lung and kidney was diminished by 69%, 39%, 83% and 40%, respectively, compared to the distribution profiles in response to fresh AgNPs. Whereby, milder splenic hyperemia was observed, and no significant hepatoxicity was found. Additionally, aged AgNPs provoked milder increase of periphery leukocytes and malondialdehyde (MDA) in mice in comparison to fresh AgNPs. Taken together, this study unraveled that the ageing process elicited remarkable alterations to physicochemical properties and toxic effects as well. This study would provide new insights into the potential health impacts of AgNPs under transformation-determined exposure scenarios.


Assuntos
Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Prata/química , Prata/toxicidade , Animais , Mamíferos , Nanopartículas Metálicas/efeitos da radiação , Camundongos , Tamanho da Partícula , Prata/metabolismo , Prata/efeitos da radiação , Luz Solar , Distribuição Tecidual , Testes de Toxicidade Aguda , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/efeitos da radiação , Poluentes Químicos da Água/toxicidade
2.
Environ Pollut ; 259: 113902, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31918149

RESUMO

A series of phosphorus containing ZnO (P-ZnO) photocatalysts with various percentages of phosphorus were successfully synthesized using the hydrothermal method. The structural, physical and optical properties of the obtained microparticles were investigated using diverse techniques such as X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible diffusion reflectance spectroscopy (UV-Vis DRS), photoluminescence (PL) spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and N2 adsorption-desorption analysis. The photocatalytic activities of the pure and P-ZnO samples were evaluated for the degradation of Rhodamine B (RhB) under visible light irradiation. The parameters such as pH, catalyst dosage, contaminant concentration and effect of persulfate as an oxidant were studied. It was found that the P-ZnO1.8% photocatalyst could destroy 99% of RhB (5 ppm) in 180 min at pH = 7; furthermore, it degraded ∼100% of 5 and 10 ppm of the RhB pollutant in 120 and 180 min, respectively, only by adding 0.01 g of persulfate into the reaction solution. To determine the photocatalytic mechanism, 2-propanol, benzoquinone and EDTA were used and it was indicated that hydroxyl radicals, superoxide ions and holes, all had major roles in the photocatalytic degradation but the hydroxyl radical effect was the most significant. The phenol degradation was also investigated using the P-ZnO1.8% optimum photocatalyst which could destroy 53% of the phenol (5 ppm) in 180 min. According to the reusability test, it was proved that after 5 cycles, the catalyst activity was not highly changed and it was potentially capable of pollutant degradation.


Assuntos
Luz , Fósforo , Purificação da Água/métodos , Óxido de Zinco , Nanopartículas Metálicas/química , Nanopartículas Metálicas/efeitos da radiação , Fósforo/química , Espectroscopia de Infravermelho com Transformada de Fourier , Purificação da Água/instrumentação , Óxido de Zinco/química
3.
J Colloid Interface Sci ; 560: 701-713, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31706655

RESUMO

Photocatalysis technology is regarded as a promising way for environmental remediation, but rationally designing photocatalysis system with high-speed interfacial charge transfer, sufficient photoabsorption and surface reactive sites is still a challenge. In this study, anchoring single-unit-cell defective Bi2MoO6 on ultrathin g-C3N4 to form 2D/2D heterostructure system is a triple-purpose strategy for high-performance photocatalysis. The defect structure broadens photo-responsive range. The large intimate contact interface area between two monomers promotes charges carrier transfer. The enhanced specific surface area exposes more reactive sites for mass transfer and catalytic reaction. As a result, the obtained heterostructure displays excellent photocatalytic performance for ciprofloxacin (CIP) (0.0126 min-1), which is 3.32 and 2.93 folds higher than Bi2MoO6 and g-C3N4. In addition, this heterostructure retains high-performance for actual wastewaters treatment, and it displays strong mineralization ability. And this heterojunction also exhibits excellent photostability based on cyclic experiment. Mechanism exploration reveals that hole, superoxide radical, and hydroxyl radical are chief reactive species toward CIP degradation, thereby a Z-scheme charge carrier transfer channel is proposed. In addition, the intermediates and degradation pathways of CIP are tracked by liquid chromatography-triple quadrupole tandem mass spectrometry (LCMS/MS) and three-dimensional excitation-emission matrix fluorescence spectroscopy (3D EEMs). This study paves new way to design and construct atomic level 2D/2D heterojunction system for environment remediation.


Assuntos
Antibacterianos/química , Bismuto/química , Ciprofloxacino/química , Nanopartículas Metálicas/química , Molibdênio/química , Nanoestruturas/química , Nitrilos/química , Antibacterianos/metabolismo , Catálise , Ciprofloxacino/metabolismo , Luz , Nanopartículas Metálicas/efeitos da radiação , Molibdênio/efeitos da radiação , Nanoestruturas/efeitos da radiação , Nitrilos/efeitos da radiação , Processos Fotoquímicos , Fotólise
4.
Anal Chim Acta ; 1090: 64-71, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31655647

RESUMO

Using carcinoembryonic antigen (CEA) imprinted polymerized ionic liquid hydrogel as a recognition element and hollow gold nanoballs/MoSe2 nanosheets as a photoactive element, a photoelectrochemical (PEC) sensing platform was successfully fabricated. To accomplish the imprinted process under room temperature to maintain the biological activity and the configuration of CEA, and thus to improve the sensing performances, 3-{[{4-N,N-Bis[(carbamoyl)ethylmethacrylate]butyl}((carbamoyl)amino)ethyl methacrylate] -propyl}-1-ethenyl-1H-imidazol-3-ium bromide (BCCPEimBr) ionic liquid was synthesized. By using BCCPEimBr ionic liquid as the functional monomer, CEA as the template, a molecularly imprinted hydrogel film was prepared on a hollow gold nanoballs/MoSe2 nanosheets modified glassy carbon electrode surface. After removing the template, a CEA imprinted photoelectrochemical sensor was successfully fabricated. The imprinted PEC sensor shows good selectivity, sensitivity and stability towards CEA, produces a linear response in the concentration range from 0.05 to 5.0 ng mL-1 and shows a detection limit of 11.2 pg mL-1 (S/N = 3) under the optimized conditions. The imprinted PEC sensor was used to determine CEA in clinical human serum samples accurately. The procedure for the imprinted PEC sensing platform can be used for other biomolecules just by substituting the template.


Assuntos
Antígeno Carcinoembrionário/sangue , Hidrogéis/química , Líquidos Iônicos/química , Nanopartículas Metálicas/química , Nanocompostos/química , Polímeros/química , Técnicas Biossensoriais/métodos , Dissulfetos/química , Técnicas Eletroquímicas/métodos , Ouro/química , Ouro/efeitos da radiação , Humanos , Limite de Detecção , Nanopartículas Metálicas/efeitos da radiação , Impressão Molecular , Molibdênio/química , Fotoquímica/métodos , Reprodutibilidade dos Testes
5.
J Chem Phys ; 151(14): 144712, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31615232

RESUMO

Electrogenerated chemiluminescence (ECL) is a promising technique for low concentration molecular detection. To improve the detection limit, plasmonic nanoparticles have been proposed as signal boosting antennas to amplify ECL. Previous ensemble studies have hinted that spectral overlap between the nanoparticle antenna and the ECL emitter may play a role in signal enhancement. Ensemble spectroscopy, however, cannot resolve heterogeneities arising from colloidal nanoparticle size and shape distributions, leading to an incomplete picture of the impact of spectral overlap. Here, we isolate the effect of nanoparticle-emitter spectral overlap for a model ECL system, coreaction of tris(2,2'-bipyridyl)dichlororuthenium(ii) hexahydrate and tripropylamine, at the single-particle level while minimizing other factors influencing ECL intensities. We found a 10-fold enhancement of ECL among 952 gold nanoparticles. This signal enhancement is attributed exclusively to spectral overlap between the nanoparticle and the emitter. Our study provides new mechanistic insight into plasmonic enhancement of ECL, creating opportunities for low concentration ECL sensing.


Assuntos
Nanopartículas Metálicas/química , Compostos Organometálicos/química , Propilaminas/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Ouro/química , Ouro/efeitos da radiação , Luz , Luminescência , Medições Luminescentes/métodos , Nanopartículas Metálicas/efeitos da radiação , Compostos Organometálicos/efeitos da radiação
6.
Analyst ; 144(21): 6193-6196, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31577279

RESUMO

We here describe a photocurrent generation system exploiting gold nanoparticles (AuNPs) that cover perylenediimide-DNA complexes on electrode surfaces. Enhanced photocurrents were generated by the irradiation of the AuNPs, attributed to the efficient excitation of the perylenediimides by a local electric field on the surface of the AuNPs.


Assuntos
DNA/química , Técnicas Eletroquímicas/métodos , Nanopartículas Metálicas/química , Fotoquímica/métodos , Técnicas Eletroquímicas/instrumentação , Eletrodos , Ouro/química , Ouro/efeitos da radiação , Imidas/química , Imidas/efeitos da radiação , Luz , Nanopartículas Metálicas/efeitos da radiação , Perileno/análogos & derivados , Perileno/química , Perileno/efeitos da radiação
7.
Analyst ; 144(19): 5717-5723, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31482883

RESUMO

An innovative visible light-driven photoelectrochemical (PEC) immunosensing system was reasonably established for the sensitive detection of prostate-specific antigen (PSA) by using perovskite metal oxide@gold nanoparticle heterostructures (BaTiO3/Au) as the photoactive materials. When plasmonic Au nanoparticles were directly decorated on BaTiO3, a several times surface plasmon resonance (SPR) enhancement of photocurrent density was induced via the injection of hot electrons from visible light-excited Au nanoparticles into the conduction band of BaTiO3, and the combination of BaTiO3 and Au nanoparticles was employed as a promising platform for developing a photoelectrochemical bioanalysis. As a proof of concept, PSA had been detected by the BaTiO3/Au nanocomposite-based PEC sensor. To design such an immunoassay protocol, a monoclonal anti-PSA capture antibody (cAb)-coated microplate and glucose oxidase/polyclonal anti-PSA detection antibody-modified gold nanoparticles (GOx-Au NP-dAb) were used as the immunoreaction platform and signal probe, respectively. Upon the addition of target PSA, a sandwiched immunocomplex was formed accompanying the immuno-recognition between the antigen and antibody, and then the carried GOx could oxidize glucose to produce H2O2. The photocurrent of the BaTiO3/Au nanocomposite-functionalized electrode amplified with increasing H2O2 concentration since H2O2 is considered as a good hole scavenger. On the basis of the above-mentioned mechanisms and the optimized conditions, the assembled PEC immunosensor was linear with the logarithm of the PSA concentration in the range of 0.01-40 ng mL-1 with a detection limit of 4.2 pg mL-1. It afforded rapid response, good precision, and high stability and specificity, implying its great promise in photoelectrochemical immunoassays. More generally, this system sets up an ideal PEC immunosensing system based on the BaTiO3/Au nanocomposites and represents an innovative and low-cost "signal-on" assay scheme for the practical quantitative screening of low-abundance proteins.


Assuntos
Compostos de Bário/química , Ouro/química , Calicreínas/sangue , Nanopartículas Metálicas/química , Antígeno Prostático Específico/sangue , Titânio/química , Anticorpos Monoclonais/imunologia , Compostos de Bário/efeitos da radiação , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Glucose/análise , Glucose Oxidase/química , Ouro/efeitos da radiação , Humanos , Peróxido de Hidrogênio/química , Imunoensaio/métodos , Calicreínas/imunologia , Luz , Limite de Detecção , Nanopartículas Metálicas/efeitos da radiação , Nanocompostos/química , Nanocompostos/efeitos da radiação , Processos Fotoquímicos , Estudo de Prova de Conceito , Antígeno Prostático Específico/imunologia , Ressonância de Plasmônio de Superfície/métodos , Titânio/efeitos da radiação
8.
Analyst ; 144(21): 6352-6364, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31560361

RESUMO

The inclusion of nanoparticles (NP) in radiotherapy has been shown to increase the damaging effect on tumor cells. However, the mechanisms of action of NP combined with radiotherapy, and the influence of NP parameters and cell type on their radiosensitization capability at molecular and cellular levels still remain unclear. Gold NP (AuNP) have become particularly popular due to their multiple advantages. Within this context, our research work aimed to study the biochemical radiosensitization capacity of F98 and U87-MG glioma cell lines to 1.9 nm AuNP combined with X-ray irradiation. For this purpose, synchrotron-based infrared microspectroscopy (SR-FTIRM) was used as a powerful tool for biochemical composition and treatment response assessment of cells at a single-cell level. SR-FTIRM data, supported by multivariate analysis, revealed clear AuNP-induced changes in the DNA, protein and lipid spectral regions. The AuNP-related biochemical alterations appear prior to the irradiation, which gave us a first indication on the AuNP radiosensitization action. Biochemical modifications induced by the AuNP in the presence of radiotherapy irradiations include enhanced conformational changes in the protein secondary structures, variations in the intensity and position in the phosphodiester bands, and changes in the CH2 and CH3 stretching modes. These changes are better manifested at 24 hours post-irradiation time. SR-FTIRM results showed a clear heterogeneity in the biochemical cell response, probably due to the distinct cell-NP interactions and thus, to different DNA damage and cell death processes.


Assuntos
Glioma/metabolismo , Nanopartículas Metálicas/química , Radiossensibilizantes/farmacologia , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , DNA/metabolismo , Dano ao DNA/efeitos dos fármacos , Ouro/química , Ouro/efeitos da radiação , Humanos , Nanopartículas Metálicas/efeitos da radiação , Análise de Componente Principal , Proteínas/metabolismo , Radiossensibilizantes/química , Radiossensibilizantes/efeitos da radiação , Ratos , Espectrofotometria Infravermelho , Síncrotrons , Raios X
9.
Proc Natl Acad Sci U S A ; 116(37): 18590-18596, 2019 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-31451630

RESUMO

Biocompatible gold nanoparticles designed to absorb light at wavelengths of high tissue transparency have been of particular interest for biomedical applications. The ability of such nanoparticles to convert absorbed near-infrared light to heat and induce highly localized hyperthermia has been shown to be highly effective for photothermal cancer therapy, resulting in cell death and tumor remission in a multitude of preclinical animal models. Here we report the initial results of a clinical trial in which laser-excited gold-silica nanoshells (GSNs) were used in combination with magnetic resonance-ultrasound fusion imaging to focally ablate low-intermediate-grade tumors within the prostate. The overall goal is to provide highly localized regional control of prostate cancer that also results in greatly reduced patient morbidity and improved functional outcomes. This pilot device study reports feasibility and safety data from 16 cases of patients diagnosed with low- or intermediate-risk localized prostate cancer. After GSN infusion and high-precision laser ablation, patients underwent multiparametric MRI of the prostate at 48 to 72 h, followed by postprocedure mpMRI/ultrasound targeted fusion biopsies at 3 and 12 mo, as well as a standard 12-core systematic biopsy at 12 mo. GSN-mediated focal laser ablation was successfully achieved in 94% (15/16) of patients, with no significant difference in International Prostate Symptom Score or Sexual Health Inventory for Men observed after treatment. This treatment protocol appears to be feasible and safe in men with low- or intermediate-risk localized prostate cancer without serious complications or deleterious changes in genitourinary function.


Assuntos
Terapia a Laser/instrumentação , Nanopartículas Metálicas/administração & dosagem , Neoplasias da Próstata/cirurgia , Idoso , Estudos de Viabilidade , Seguimentos , Ouro/administração & dosagem , Ouro/efeitos da radiação , Humanos , Biópsia Guiada por Imagem/métodos , Raios Infravermelhos , Terapia a Laser/efeitos adversos , Terapia a Laser/métodos , Imagem por Ressonância Magnética Intervencionista/efeitos adversos , Imagem por Ressonância Magnética Intervencionista/instrumentação , Imagem por Ressonância Magnética Intervencionista/métodos , Masculino , Nanopartículas Metálicas/efeitos da radiação , Pessoa de Meia-Idade , Imagem Multimodal/efeitos adversos , Imagem Multimodal/instrumentação , Imagem Multimodal/métodos , Nanoconchas/administração & dosagem , Nanoconchas/efeitos da radiação , Oligopeptídeos , Órgãos em Risco/efeitos da radiação , Ereção Peniana/efeitos da radiação , Projetos Piloto , Próstata/diagnóstico por imagem , Próstata/patologia , Próstata/cirurgia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Saúde Sexual , Ultrassonografia de Intervenção/efeitos adversos , Ultrassonografia de Intervenção/instrumentação , Ultrassonografia de Intervenção/métodos , Sistema Urogenital/efeitos da radiação
10.
Nanotechnology ; 30(49): 495501, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31443101

RESUMO

With the capability of inducing small particle sizes of supported metal in graphite oxide (GO), the γ-ray irradiation method applied for preparing graphite oxide-gold (GO-Au) nanocomposites as electrochemical immunosensors has attracted specific attention recently. To study the accurate factors influencing the precise morphology and final performance of the prepared composites in the γ-irradiation system, we proposed a facile method to investigate the evolution of the GO structure, size and dispersion of Au nanoparticles (AuNPs) produced with the addition of isopropyl alcohol to the system. The GO-Au nanocomposites were characterized by Fourier transform infrared spectroscopy, x-ray diffraction spectra, Raman spectra, x-ray photoelectron spectroscopy and high resolution transmission electron microscopy. These nanocomposites with sandwich morphology exhibited an excellent immunosensor performance with a low detection limit of 15.8 pg ml-1 (S/N = 3) and a wide linear range from 1 to 40 ng ml-1 for detecting carcinoembryonic antigens. The enhanced biosensing performance is attributed to the synergistic effect of γ-irradiation and the precise structure of GO, which endows the smaller size and more uniform distribution of AuNPs on the GO as well as the good signal amplification capability. Furthermore, adopting the γ-irradiation method and use of GO as a precursor is propitious for application in large-scale production because of its high-efficiency and high-yielding characteristics.


Assuntos
Técnicas Biossensoriais , Antígeno Carcinoembrionário/sangue , Ouro/química , Imunoensaio , Nanopartículas Metálicas/química , Nanocompostos/química , 2-Propanol/química , Anticorpos Imobilizados/química , Técnicas Eletroquímicas , Raios gama , Grafite/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/efeitos da radiação , Nanopartículas Metálicas/ultraestrutura , Nanocompostos/efeitos da radiação , Nanocompostos/ultraestrutura , Óxidos/química
11.
Chem Commun (Camb) ; 55(61): 9039-9042, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31292589
12.
Talanta ; 204: 548-554, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357332

RESUMO

In this paper, a new strategy was presented for fluorescence labeling and imaging Al3+ in live cells with excess aluminum ions using thiolated fluorescence gold nanoclusters (Au NCs). The glutathione (GSH)-capped Au NCs were prepared via a green, facile one-pot method in aqueous solution and displayed excellent stability, ultrasmall size, monodispersity, and larger Stokes shift, which exhibits a relatively weak fluorescence at 650 nm Al3+-induced fluorescence enhancement of the GSH-Au NCs can be observed due to Al3+-triggered aggregation-induced emission (AIE) effect, which allows the role of GSH-Au NCs as a fluorescence light-up probe for detection of Al3+. Moreover, it was demonstrated that the fluorescence probe for Al3+ showed a wide detection range from 100 to 600 µM and good selectivity against other metal ions and common biomolecule. Furthermore, due to the advantages of excellent biocompatibility, low toxicity, red emission and high specificity, the proposed GSH-Au NCs fluorescence probes are suitable for the imaging of high concentrations of aluminum ions in cells, which can be applied to the diagnosis of cellular aluminum poisoning.


Assuntos
Alumínio/análise , Técnicas Biossensoriais/métodos , Corantes Fluorescentes/química , Glutationa/química , Ouro/química , Nanopartículas Metálicas/química , Linhagem Celular , Fluorescência , Corantes Fluorescentes/efeitos da radiação , Corantes Fluorescentes/toxicidade , Glutationa/toxicidade , Ouro/efeitos da radiação , Ouro/toxicidade , Humanos , Nanopartículas Metálicas/efeitos da radiação , Nanopartículas Metálicas/toxicidade , Raios Ultravioleta
13.
Phys Med Biol ; 64(15): 155016, 2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31300616

RESUMO

Nanoparticles (NPs) containing high atomic number (high-Z) materials have been shown to enhance the radiobiological effectiveness of ionizing radiation. This effect is often attributed to an enhancement of the absorbed dose in the vicinity of the NPs, based on Monte Carlo simulations that show a significant local enhancement of the energy deposition on the microscopic scale. The results of such simulations may be significantly biased and lead to a severe overestimation of the dose enhancement if the condition of secondary particle equilibrium is not met in the simulation setup. This current work shows an approach to estimate a 'realistic' dose enhancement from the results of such biased simulations which is based on published photon interaction data and provides a way for correcting biased results.


Assuntos
Nanopartículas Metálicas/efeitos da radiação , Radiossensibilizantes/efeitos da radiação , Simulação por Computador , Ouro/química , Humanos , Nanopartículas Metálicas/química , Método de Monte Carlo , Fótons , Doses de Radiação , Radiossensibilizantes/química
14.
Methods Appl Fluoresc ; 7(3): 034004, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31174198

RESUMO

In this work, we report a sensitive and selective turn-on fluorescence detection of cysteine with glutathione protected silver nanoclusters (GSH-Ag NCs). The glutathione stabilized silver nanoclusters were synthesized by the boiling water method. When excited at 380 nm, the GSH-Ag NCs exhibited a weak emission at about 680 nm, which could be enhanced by cysteine. The proposed method allows evaluation of cysteine in the range of 2-3000 µM with a detection limit of 0.51 µM. The recoveries were found to be 95.07%-101.38% when detecting cysteine contents in fetal bovine serum samples. In addition, we also discussed the possible mechanism for the fluorescence enhancement of GSH-Ag NCs by addition of cysteine. It might be the formation of cysteine and glutathione co-capped Ag NCs. This work reported a fluorimetric method for the assay of cysteine and provided a strategy for the synthesis of dual ligand-protected Ag nanoclusters.


Assuntos
Cisteína/sangue , Corantes Fluorescentes/química , Glutationa/química , Nanopartículas Metálicas/química , Prata/química , Animais , Bovinos , Cisteína/química , Fluorescência , Corantes Fluorescentes/efeitos da radiação , Limite de Detecção , Nanopartículas Metálicas/efeitos da radiação , Prata/efeitos da radiação , Espectrometria de Fluorescência/métodos , Raios Ultravioleta
15.
Analyst ; 144(11): 3552-3555, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31049496

RESUMO

Here we demonstrate light mediated heating of nanoparticles confined deep inside mammalian tissue, whilst directly monitoring their temperature non-invasively using a form of deep Raman spectroscopy, T-SESORS. One of the main barriers to the introduction of photo-thermal therapies (PTT) has been recognised as the inability to directly monitor the local temperature deep within the tissue at the point of therapy. Here Au nanoparticles with a Raman reporter molecule (temperature reporters) are used in combination with Au nanoshells (heat mediators) to provide simultaneously heating under NIR illumination and direct spectroscopic monitoring of local temperature deep within mammalian tissues. The surface enhanced Raman signal was read out at the tissue surface using a transmission geometry in this example and the temperature of the tissue was ascertained from the anti-Stokes to Stokes Raman reporter. This approach opens the prospect of non-invasive hyperthermia treatments with direct temperature feedback from deep inside within tissue, where nanoparticles can be used to both provide localised heating and accurately monitor the local temperature.


Assuntos
Febre/metabolismo , Análise Espectral Raman/métodos , Temperatura , Termometria/métodos , Animais , Benzoatos/química , Benzoatos/efeitos da radiação , Ouro/química , Raios Infravermelhos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/efeitos da radiação , Estudo de Prova de Conceito , Compostos de Sulfidrila/química , Compostos de Sulfidrila/efeitos da radiação , Suínos
16.
ACS Sens ; 4(6): 1670-1681, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31117365

RESUMO

Semiconductor materials have become competitive candidates for surface-enhanced Raman scattering (SERS) substrates; however, their limited SERS sensitivity hinders the practical applications of semiconductors. Here, we develop a hybrid substrate by integrating anatase/rutile TiO2 heterostructure with dense plasmonic hotspots of Ag nanoparticle (AgNPs) for efficient photoinduced enhanced Raman spectroscopy (PIERS). The PIERS mechanism is systematically investigated by means of a portable Raman instrument. When ultraviolet (UV) light irradiates the substrate, the TiO2-Ag hybrid arrays produce remarkable charge-transfer enhancement, which can be ascribed to the highly efficient charge separation driven by heterojunction and transfer from TiO2 heterostructure to AgNPs. This platform allows for the rapid detection of multifold organic species, including malachite green (MG), crystal violet (CV), rhodamine 6G (R6G), thiram, and acephate, and as high as 27.8-fold enhancement over the normal SERS is achieved, representing the highest PIERS magnification up to the present time. The intensive PIERS enhancement makes it ultrasensitively detect analyte concentration of an order of magnitude lower than that of SERS method. The improved sensitivity and resolution can be readily realized by simple UV irradiation, which represents a major advantage of our PIERS methodology. Besides, the integration of uniform TiO2 heterostructure arrays with AgNPs generates superior signal reproducibility with relative standard deviation (RSD) value of less than 14%. In addition, the detected molecules on the substrate can be eliminated by photocatalytic degradation after PIERS measurements by using UV irradiation, which makes the substrate reusable for 15 cycles. The ultrahigh sensitivity, superior reproducibility, and excellent recyclability displayed by our platform may provide new opportunities in field detection analysis coupled with a portable Raman instrument.


Assuntos
Poluentes Ambientais/análise , Nanopartículas Metálicas/química , Semicondutores , Violeta Genciana/análise , Limite de Detecção , Nanopartículas Metálicas/efeitos da radiação , Nanotubos/química , Nanotubos/efeitos da radiação , Compostos Organotiofosforados/análise , Fosforamidas , Reprodutibilidade dos Testes , Rodaminas/análise , Corantes de Rosanilina/análise , Prata/química , Prata/efeitos da radiação , Análise Espectral Raman/métodos , Tiram/análise , Titânio/química , Titânio/efeitos da radiação , Raios Ultravioleta
17.
Carbohydr Polym ; 216: 189-196, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31047056

RESUMO

In this study, the composite of carboxymethyl cellulose (CMC) film modified with gelatin and TiO2-Ag nanoparticles (CMC/Gel/TiO2-Ag) was prepared and some properties of synthesized film including physicochemical and photocatalytic properties were investigated. FT-IR results showed that new interactions between the film components were created. Scanning electron microscopy (SEM) results showed that the TiO2-Ag particles with 50-100 nm distributed in the CMC/Gelatin film. The results of the mechanical test showed that the TiO2-Ag nanoparticles at low concentrations increased tensile strength (TS) and decreased strain to break (STB), but with increasing nanoparticles concentrations, TS decreased and STB increased. Photocatalytic study showed that the prepared CMC/Gel/TiO2-Ag film has good photocatalytic property. Gas chromatography was used to study photocatalytic effects of film. Increasing TiO2-Ag nano particles on the film increases the photocatalytic activity of films against NH3, ethanol and benzene.


Assuntos
Plásticos Biodegradáveis/química , Carboximetilcelulose Sódica/química , Gelatina/química , Nanopartículas Metálicas/química , Prata/química , Titânio/química , Amônia/química , Benzeno/química , Plásticos Biodegradáveis/síntese química , Plásticos Biodegradáveis/efeitos da radiação , Carboximetilcelulose Sódica/síntese química , Carboximetilcelulose Sódica/efeitos da radiação , Catálise , Módulo de Elasticidade , Etanol/química , Gelatina/síntese química , Gelatina/efeitos da radiação , Luz , Membranas Artificiais , Nanopartículas Metálicas/efeitos da radiação , Nanocompostos/química , Nanocompostos/efeitos da radiação , Permeabilidade , Prata/efeitos da radiação , Vapor , Resistência à Tração , Titânio/efeitos da radiação , Água/química
18.
Carbohydr Polym ; 217: 15-25, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31079671

RESUMO

A bifunctional interfacial layer was introduced onto the surface of cotton fabric which not only enhanced the interfacial bonding between Ag@ZnO and organic substrates but also improved the photocatalytic performance simultaneously. In detail, a modified cotton fabric (denoted as Cot-g-Si/Ag@ZnO) was fabricated through radiation-induced graft polymerization of γ-methacryloxypropyl trimethoxysilane and followed the in-situ formation of ZnO and loading of Ag nanoparticles simultaneously. Owing to ZnOSi between the graft chains and Ag@ZnO photocatalyst, the charge carrier concentration increased and Ag was prevented from oxidizing through the partial separation from ZnO, leading to enhanced near-field amplitudes of the localized surface plasmon resonance. Cot-g-Si/Ag@ZnO also exhibited excellent photocorrosion resistance, photostability and laundering durability. Its photocatalytic activity was fully maintained after several photodegradation cycles; moreover, after laundering durability test, the photocatalytic activity was improved compared with the newly prepared one. Credible mechanism for the photocatalytic activity of Cot-g-Si/Ag@ZnO under sunlight irradiation is proposed.


Assuntos
Antibacterianos/farmacologia , Fibra de Algodão , Nanopartículas Metálicas/química , Siloxanas/farmacologia , Prata/química , Óxido de Zinco/farmacologia , Antibacterianos/química , Antibacterianos/efeitos da radiação , Catálise , Escherichia coli/efeitos dos fármacos , Gossypium/química , Luz , Nanopartículas Metálicas/efeitos da radiação , Azul de Metileno/efeitos da radiação , Fotólise , Rodaminas/efeitos da radiação , Siloxanas/química , Siloxanas/efeitos da radiação , Prata/efeitos da radiação , Staphylococcus aureus/efeitos dos fármacos , Óxido de Zinco/química , Óxido de Zinco/efeitos da radiação
19.
Phys Med ; 60: 22-29, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31000082

RESUMO

OBJECTIVE: The metric dose enhancement ratio (DER) has been widely used to assess the enhancing capability of gold nanoparticles (GNPs). However, there is a large disparity between the observed radiobiological outcome and DER values. A new metric, linear energy transfer enhancement ratio (LETER), is introduced to bridge the gap between theoretical predictions and the experimentally measured sensitization. METHODS: The radiation transport code SCEPTRE is used to examine the efficacy of the proposed new metric. Different clusters of GNPs irradiated with x-ray photons generated at 120 kVp and therapeutic 6 MV photon beams are investigated. For each pattern, two GNPs sizes are examined 50 and 100 nm. RESULTS: An enhancement in the linear energy transfer has been observed for both energies. In the case of 120 kVp, LETER is substantially lower than DER; moreover, it decreases with increasing GNP size. On the other hand, the results of 6 MV show that LETER is relatively higher than DER, and it increases with the size of GNP. For the studied energies, LETER is in good agreement with the sensitization reported in the literature. CONCLUSION: The results indicate the merit of LETER as a better indicator of the radiobiological outcome of GNP aided radiotherapy.


Assuntos
Compostos de Ouro/efeitos da radiação , Nanopartículas Metálicas/efeitos da radiação , Modelos Teóricos , Fótons/uso terapêutico , Radiossensibilizantes/efeitos da radiação , Simulação por Computador , Elétrons , Compostos de Ouro/uso terapêutico , Nanopartículas Metálicas/uso terapêutico , Tamanho da Partícula , Radiossensibilizantes/uso terapêutico , Dosagem Radioterapêutica , Raios X
20.
Analyst ; 144(8): 2820-2826, 2019 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-30882805

RESUMO

Developing a sensitive and selective detection platform of disease-related biomarkers is important for the diagnosis and treatment of diseases at an early stage. Among clinically meaningful biomarkers, proteins are the most commonly used indicators, and they are generally detected via immunoassays. However, the use of conventional immunoassays in early diagnosis is hindered by the time required, complex steps, high-cost, and insufficient sensitivity and selectivity. Herein, we developed a novel on-chip immunoassay with degassing-driven microfluidic devices and gold nanoplasmonic particles (GNPs). To recognize target proteins, antibody-conjugated GNPs as probes were used in the assay owing to their excellent scattering properties. Using the proposed nonenzymatic immunoassay, we detected amyloid ß (Aß) and Tau proteins, representative biomarkers of Alzheimer's disease, in femtomolar levels. Selective and quantitative detection of Aß spiked in blood plasma was also achieved for further clinical application of the proposed immunoassay. The proposed plasmonic immunoassay integrated with degassing-driven microfluidic chips provides a new platform for biological assays and diagnosis.


Assuntos
Peptídeos beta-Amiloides/sangue , Imunoensaio/métodos , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/métodos , Proteínas tau/análise , Peptídeos beta-Amiloides/imunologia , Anticorpos Monoclonais/imunologia , Ouro/química , Ouro/efeitos da radiação , Humanos , Limite de Detecção , Nanopartículas Metálicas/química , Nanopartículas Metálicas/efeitos da radiação , Técnicas Analíticas Microfluídicas/instrumentação , Proteínas tau/imunologia
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