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2.
J Photochem Photobiol B ; 197: 111530, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31279287

RESUMO

A novel nano-formulations of biocompatible, biodegradable and thermo-responsive graphene quantum dots (GQDs) loaded dextran/poly(N-isopropylacrylamide) (Dex/PNIPAM) copolymeric matrix was synthesized and analyzed the materials characterization, sustained drug delivery system, tissue feasibility in the tissue implantation site. This research report was aimed to grafting and functionalizing thermo-responsive (Dex/PNIPAM) copolymeric composite with presence of graphene quantum dots to achieve thermal responsive drug delivery (TrDD) with no harm effect in the implantation site. The synthesized GQD by using ionic liquid were evaluated by spectroscopic (DLS, PL, XRD and Raman spectroscopy) and Transmission electron microscopic analysis (TEM). The ultra-small GQDs loaded Dex/PNIPAM and was appeared to be asymmetric and open uniform porous structure, which can be significantly favorable for cell uptake and greatly influenced to be an effective drug carrier into the cellular compartment with good fluid flow. The PNIPAM polymeric composite were exhibited sustained and enhanced drug release percentages with increasing temperature at above low critical solution temperature (LCST) is 39 °C comparable to the cumulative drug release profile of below LCST (32 °C), which demonstrated that thermo-responsive polymer was played a significant role in the delivery system. The treated group of GQDs-Dex/PNIPAM was observed that no inflammation and shows noteworthy stromal cell infiltration, demonstrating that the synthesized drug carriers did not harm to the nerves and tissues and only was responsible for the pain management.


Assuntos
Buprenorfina/química , Portadores de Fármacos/química , Grafite/química , Hidrogéis/química , Manejo da Dor , Pontos Quânticos/química , Resinas Acrílicas/química , Animais , Buprenorfina/uso terapêutico , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dextranos/química , Portadores de Fármacos/farmacologia , Feminino , Corantes Fluorescentes/química , Glicóis/química , Hidrogéis/farmacologia , Camundongos , Músculo Esquelético/patologia , Dor/tratamento farmacológico , Ratos , Ratos Sprague-Dawley
3.
J Photochem Photobiol B ; 197: 111545, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31326847

RESUMO

Proper waste utilization in order to promote value added product is a promising scientific practice in recent era. Inspiring from the recurring trend, we propose a single step oxidative pyrolysis derived fluorescent carbon dots (C-dots) from Allium sativum peel, which is a natural, nontoxic, and waste raw material. Because of its excellent optical properties, and photostability this C-dots have been used in versatile area of applications. Due to its immediate water dispersing character, C-dots reinforced Poly(acrylic acid) (PAA) films revealed improvement in uniaxial stretching behavior and can be used as transparent sunlight conversion film. The nanocomposite film has been tested against rigorous simulated sunlight which proved almost identical sunlight conversion behavior with no photo-bleachable character which is definitely added an extra quality of transparent polymer films. Moreover, the C-dots dispersion has been used as in vitro biomarker for living cells owing to its ease in solubility, biocompatibility, non-cytotoxicity and bright fluorescence even in subcutaneous environment. For this case, adipose derived mesenchymal stem cells (ADMSCs) have been chosen and injected to rabbit ear skin to perform two-photon imaging experiment. The present work opens a new avenue towards the large-scale synthesis of bio-waste based fluorescent C-dots, paving the way for their versatile applications.


Assuntos
Allium/química , Nitrogênio/química , Fotodegradação/efeitos da radiação , Pontos Quânticos/química , Enxofre/química , Luz Solar , Resinas Acrílicas/química , Tecido Adiposo/citologia , Allium/metabolismo , Animais , Materiais Biocompatíveis/química , Carbono/química , Sobrevivência Celular/efeitos dos fármacos , Frutas/química , Frutas/metabolismo , Química Verde , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Microscopia de Fluorescência , Pontos Quânticos/toxicidade , Coelhos , Pele/efeitos dos fármacos , Pele/patologia , Solubilidade
4.
Chem Commun (Camb) ; 55(61): 8963-8966, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31290488

RESUMO

We develop a simple method for sensitive detection of alkaline phosphatase (ALP) based on the ligase amplification reaction-catalyzed assembly of a single quantum dot (QD)-based nanosensor. This nanosensor requires only a single ligase enzyme to achieve ultrahigh sensitivity with a detection limit of 5.63 × 10-7 U mL-1, and can be applied for kinetic analysis, inhibitor screening, and ALP measurement in cell extracts.


Assuntos
Fosfatase Alcalina/análise , Técnicas Biossensoriais/métodos , DNA Ligases/química , Ensaios Enzimáticos/métodos , Transferência Ressonante de Energia de Fluorescência/métodos , Pontos Quânticos/química , Biotina/química , Carbocianinas/química , DNA/química , DNA/genética , Sondas de DNA/química , Sondas de DNA/genética , Fluorescência , Células HEK293 , Humanos , Limite de Detecção , Células MCF-7 , Hibridização de Ácido Nucleico , Imagem Individual de Molécula , Estreptavidina/química
5.
J Agric Food Chem ; 67(32): 9096-9103, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31356079

RESUMO

A monoclonal antibody (mAb) was raised against tebuconazole (TEB) using a hapten where the p-chloro substituent of the TEB molecule was replaced with a long-chain carboxylic acid. The resulting mAb showed high sensitivity and specificity against TEB characterized by ELISA with a half-maximal inhibitory concentration (IC50) of 0.19 ng mL-1 and with cross-reactivity (CR) values below 0.01% to several analogues of triazole fungicides. On the basis of the mAb produced, a quantum dot beads-based fluorescence immunochromatographic test strip assay (QBs-FITSA) was developed for rapid and sensitive detection of TEB in agricultural product samples. The QBs-FITSA exhibited a linear detection range from 0.02 to 1.25 ng mL-1 with a limit of detection (LOD) of 0.02 ng mL-1. Furthermore, using produced mAb, multiple high-throughput rapid immunoassay formats could be achieved as a convenient monitoring tool for evaluation of human and environmental exposure to TEB.


Assuntos
Brassica/química , Cucumis sativus/química , Fungicidas Industriais/análise , Imunoensaio/métodos , Triazóis/análise , Triticum/química , Anticorpos Monoclonais/análise , Contaminação de Alimentos/análise , Fungicidas Industriais/isolamento & purificação , Imunoensaio/instrumentação , Limite de Detecção , Pontos Quânticos/química , Triazóis/isolamento & purificação
6.
Talanta ; 202: 230-236, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31171175

RESUMO

Rapid and non-destructive detection of circulating tumor cells (CTCs) with no disruption of their functions is of great significance for clinical tumor therapy. However, many existing methods for CTC detection commonly rely on conventional three-color immunofluorescence identification, which damages CTCs and easily causes loss of cells. Here, we employed a method to simultaneously capture and authenticate CTCs based on immunonanocomposites (ZnS:Mn2+ QDs and Fe3O4/SiO2) equipped with permanent fluorescent and magnetic properties. A multifunctional nanocomposite was synthesized by encapsulating ZnS:Mn2+ quantum dots (QDs) and Fe3O4 nanoparticles into SiO2 nanospheres and bio-conjugating tumor-specific anti-EpCAM antibodies onto the surface. The resulting nanocomposite had a high tumor cell binding ability, and the Fe3O4 nanoparticles had a rapid magnetic response that enabled capture of circulating tumor cells from patients' blood within minutes. In addition, the cell-immunonanocomposites complexes could be directly recognized by the yellow-orange light emitted by the ZnS:Mn2+ quantum dots, thus labeling cells without utilizing the complicated and destructive procedures involved in traditional CTCs identification. We successfully achieved a high capture efficiency of up to 90.8%, and the specific fluorescence labeling of CTCs was realized in 9 clinical breast cancer patients' samples. Furthermore, this simple, convenient and cell-friendly approach is significant for solving the problems of cell viability and enables non-destructive CTC detection, which marks an advance in cancer treatment and clinical applications.


Assuntos
Nanopartículas de Magnetita/química , Manganês/química , Células Neoplásicas Circulantes/patologia , Pontos Quânticos/química , Sulfetos/química , Compostos de Zinco/química , Linhagem Celular , Humanos , Tamanho da Partícula , Propriedades de Superfície
7.
Talanta ; 202: 452-459, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31171207

RESUMO

Despite the success in long-term storage of food and dietary products using antibiotics as supplements, enormous levels of their residues have remained as a significant health concern, leading to severe toxicity issues on consumption. Herein, we report an ultrasensitive and highly selective aptasensor based on carbon nanoparticles (CNPs) through a fluorescence-based aptamer-linked immunosorbent assay (FALIA) for rapid detection of kanamycin (KAA) residue. The fabricated CNP-aptasensor exhibited superior selectivity with exceptional photoluminescence properties. Under the optimal conditions, the linear equation of standard KAA solution was Y = -0.2279LogX+1.3648 (R = -0.9893) ranged from 10-4 to 10-7 ppb with excellent relative standard deviations (RSD) between 3.12 and 5.59 % (n = 3). Moreover, the limit of detection (LOD) was lower than 5.0 × 10-8 ppb. Together, the excellent recovery and significant efficacy in the rapid detection of antibiotics at a low level in milk indicate that this fabricated CNP-aptasensor has a great potential in the establishment of an efficient antibiotic detector system in food and other nutraceutical industries.


Assuntos
Aptâmeros de Nucleotídeos/química , Carbono/química , Técnicas de Imunoadsorção , Canamicina/análise , Luminescência , Pontos Quânticos/química
8.
Chem Soc Rev ; 48(15): 4281-4316, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31215906

RESUMO

Carbon-based quantum particles, especially spherical carbon quantum dots (CQDs) and nanosheets like graphene quantum dots (GQDs), are an emerging class of quantum dots with unique properties owing to their quantum confinement effect. Many reviews appeared recently in the literature highlighting their optical properties, structures, and applications. These papers cover a broad spectrum of carbon-based nanoparticles, excluding a more detailed discussion about some important aspects related to the definition of carbon-based particles and the correlation of optical and electrochemical aspects in relation to sensing and biomedical applications. A large part of this review is devoted to these aspects. It aims, in particular, to act as a bridge between optical and electrochemical aspects of carbon-based quantum particles, both of which are associated with the electronic nature of carbon-based quantum particles. A special focus will be on their use in electroanalysis, notably their benefits in redox, and in electrochemical analysis with emphasis on their application as sensors. Electroanalysis is an easy and cost-effective means of providing qualitative and quantitative information of a specific analyte in solution in a time scale of some minutes. The integration of carbon-based quantum particles into these detection schemes as well as their incorporation into composite nanomaterials have largely improved detection limits with possibilities for their integration in aspects ranging from point-of-care devices to personalized medicine. This review will focus on some of these aspects while also covering the nanomedical aspects of carbon-based quantum particles, ultimately correlated for such developments.


Assuntos
Tecnologia Biomédica , Técnicas Biossensoriais , Carbono/química , Técnicas Eletroquímicas , Pontos Quânticos/química , Animais , Humanos , Sistemas Automatizados de Assistência Junto ao Leito
9.
Anal Bioanal Chem ; 411(20): 5277-5285, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31161325

RESUMO

Rapid, highly sensitive detection of tau protein and other neurodegenerative biomarkers remains a significant hurdle for diagnostic tests for Alzheimer's disease. In this work, we developed a novel tyrosinase (TYR)-induced tau aptamer-tau-tau antibody (anti-tau) sandwich fluorescence immunoassay to detect tau protein that used dopamine (DA)-functionalized CuInS2/ZnS quantum dots as the fluorophore. CuInS2/ZnS core/shell quantum dots with high luminescence, low toxicity, and excellent biocompatibility were successfully fabricated and decorated with DA through amide conjugation. Meanwhile, TYR was conjugated with anti-tau by a click reaction. When DA-functionalized CuInS2/ZnS quantum dots were added to the sandwich system, TYR catalyzed the transformation of DA to dopamine quinone, which acted as an effective electron acceptor and triggered fluorescence quenching. The fluorescence intensity of the immunoassay based on DA-functionalized CuInS2/ZnS quantum dots shows good performance in terms of linearity with the logarithm of tau protein concentration, with a linear concentration range from 10 pM to 200 nM. This work is the first to use a TYR-induced fluorescence immunoassay for the rapid detection of tau protein, paving a new way for the detection of disease biomarkers. Graphical abstract.


Assuntos
Cobre/química , Imunofluorescência/métodos , Índio/química , Monofenol Mono-Oxigenase/química , Pontos Quânticos/química , Selênio/química , Sulfetos/química , Compostos de Zinco/química , Proteínas tau/análise , Cristalografia por Raios X , Dopamina/análogos & derivados , Dopamina/química , Microscopia Eletrônica de Transmissão , Análise Espectral/métodos
10.
Food Chem ; 295: 530-536, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174792

RESUMO

In this work, new detection route for ascorbic acid was designed. First, highly luminescent sulfur and nitrogen doped graphene quantum dots (S,N-GQDs) were prepared via simple hydrothermal method using citric acid and thiourea as the C, N and S sources respectively. The prepared S,N-GQDs are characterized by XRD, HRTEM, FTIR, EDS and PL. Investigations showed that prepared S,N-GQDs have a good photostability and excitation-dependent emission fluorescence. Prepared S,N-GQDs showed maximum excitation wavelength and emission wavelength at 400 and 462 nm, respectively. In the following, prepared S,N-GQDs were applied as a photoluminescence probe for detection of ascorbic acid (AA). The designed sensor was based on "off-on" detection mode. The developed sensor had a linear response to AA over a concentration range of 10-500 µM with a detection limit of 1.2 µM. The regression equation is Y = 0.0014 X + 1.2036, where Y and X denote the fluorescence peak intensity and AA concentration, respectively.


Assuntos
Ácido Ascórbico/análise , Grafite/química , Pontos Quânticos/química , Espectrometria de Fluorescência/métodos , Limite de Detecção , Nanoestruturas/química , Nitrogênio/química , Enxofre/química
11.
Analyst ; 144(13): 3999-4005, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31172144

RESUMO

Micrococcal nuclease (MNase) is an extracellular endonuclease of Staphylococcus aureus (S. aureus). It digests single stranded nucleic acid. The presence of MNase is the gold standard to identify S. aureus and its content. The present study reports the ultrahigh sensitive and selective fluorescence platform for MNase detection, designed and developed based on the surface energy transfer mechanism. A "proof of concept" is being developed based on monoclonal antibody-conjugated quantum dots (mAb-QDs), wherein mAb-QDs act as donors and graphene oxide (GO) acts as an acceptor. mAb-QDs in close proximity to GO undergo adsorption due to weak affinity between them and this results in fluorescence quenching by the transfer of surface energy from mAb-QDs to GO. During sensing, a much stronger affinity of mAb-QDs towards MNase inhibits the energy transfer to GO and this allows the regaining of fluorescence. Immobilized mAb-QDs on nitrocellulose membrane strips were fabricated and tested for "ON-OFF-ON" sensing of MNase. The limit of detection for fluorescence based assay and strips is found to be 0.3 ng mL-1 and 0.5 ng mL-1, respectively. The developed strips were applied on real samples for the detection of S. aureus.


Assuntos
Corantes Fluorescentes/química , Grafite/química , Nuclease do Micrococo/análise , Pontos Quânticos/química , Staphylococcus aureus/química , Anticorpos Monoclonais/química , Técnicas Biossensoriais/métodos , Colódio/química , Transferência Ressonante de Energia de Fluorescência/métodos , Limite de Detecção , Membranas Artificiais , Nanocompostos , Estudo de Prova de Conceito , Sensibilidade e Especificidade , Staphylococcus aureus/enzimologia
12.
J Environ Sci (China) ; 83: 195-204, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221382

RESUMO

A novel functional fiber (PAN-CDs) loaded with carbon dots (CDs) with excellent photoreduction and adsorption properties for Cr(VI) was prepared via an amidization reaction between the CDs' carboxyl groups and amine groups on polyacrylonitrile (PAN)-based ion exchange fibers, which could completely preserve the fluorescence properties of the CDs. The photoluminescence (PL), photocatalysis and adsorption properties of PAN-CDs were characterized and analyzed. The PAN-CDs possess high adsorption capacity (297.6 mg/g) and excellent kinetic behavior (attaining adsorption equilibrium in 30 min) for Cr(VI) adsorption. Furthermore, the residual Cr(VI) (approximately 3 mg/L) after adsorption could be removed completely by subsequent photoreduction by the PAN-CDs. The Cr-saturated PAN-CDs could be easily separated by filtering and regenerated, with no observable decay of removal efficiency after five regeneration cycles. In addition, due to the PL quenching action of Cr(VI), the PAN-CDs can also be used as sensor for quantitative detection of trace Cr(VI) in aqueous solution.


Assuntos
Cromo/química , Poluentes Químicos da Água/química , Resinas Acrílicas/química , Adsorção , Carbono/química , Cromo/análise , Pontos Quânticos/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos
13.
Int J Nanomedicine ; 14: 3273-3282, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190793

RESUMO

Background: Biotemplates are attractive templates for the synthesis of nanometals and inorganic compound nanostructures. Methods: In this work, for the first time, iron oxide quantum dot nanoparticles (QDNPs) were prepared using albumen as a biotemplate. Next, the prepared nanoparticles were characterized using dynamic light scattering for determination and evaluation of the hydrodynamic diameter and zeta potential of the particles. Moreover, optical and scanning electron microscopes were applied to evaluate morphology. Spherically shaped iron oxide QDNPs were obtained with appropriate particle size and distribution. Fe(NO3)3.9H2O and egg whites were used as the source of the Fe element and particle size control agent in the aqueous medium, respectively. Afterward, the effect of calcination temperature parameters on the crystallinity purity and size of Fe nanocrystals were investigated. Also, products were characterized by various detection analyses such as thermogravimetry analysis/DTA, XRD, UV-vis, Fourier transform infrared (FT-IR,) transmission electron microscopy, and SEM. In order to investigate the antibacterial effect of the synthesized Fe nanobiological samples against bacterial strains, they were dissolved in dimethyl sulfoxide and diluted using distilled water. Then, different serial dilutions of 64 µg/mL, 32 µg/mL, 16 µg/mL, 8 µg/mL, 4 3BCg/mL, 2 µg/mL, 1 µg/mL, and 0.5 µg/mL of nanobiological samples were prepared and added to the Mueller-Hinton agar medium. Results: The minimum inhibitory concentration of the synthesized iron oxide quantum dot nanobiological was determined against pathogenic microbial strains of bacteria including Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, Micrococcus luteus, Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, and Klebsiella pneumonia on the culture medium plate. Conclusion: The present nanobiological samples can be considered as a new material candidate for antibacterial drugs.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Proteínas do Ovo/química , Compostos Férricos/química , Nanopartículas/química , Pontos Quânticos/química , Animais , Difusão Dinâmica da Luz , Camundongos , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Espectrofotometria Ultravioleta , Difração de Raios X
14.
J Photochem Photobiol B ; 197: 111532, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31212245

RESUMO

Glutathione (GSH) plays critical roles in many physiological processes usually present in live cells, and altered levels have been linked to some clinical pathological conditions. However, current techniques of GSH detection with fluorescence assay strategies remain poorly researched. In this work, branched polyethylenimine-functionalized carbon dots (PEI-CDs) are synthesized by simple hydrothermal treatment of glucose and PEI. The fluorescence of the PEI-CDs could be efficiently quenched by Cu2+ and then recovered by some biothiols. Basing on this, a "turn-on" fluorescent probe for detecting GSH has been developed using PEI-CDs-Cu2+ system. Compared with traditional probes for GSH detection, a significant advantage of the PEI-CDs-Cu2+ system is that it can be used for GSH detection at both low and high concentrations with different concentration combinations of PEI-CDs and Cu2+. More specifically, two good linear relationships are achieved in the ranges of 0-80 µM and 0-1400 µM for GSH, respectively. Correspondingly, the detection limits of GSH are 0.33 µM and 9.49 µM, respectively. The quantum yields (QYs) of PEI-CDs and PEI-CDs-Cu2++GSH was 9.6% and 4.2%, respectively. Moreover, the PEI-CDs-Cu2+ has excellent optical stability and good biocompatibility. Additionally, it is worth noting that the developed probe has successfully realized the visualization of GSH detection in MGC-803 cells.


Assuntos
Cobre/química , Corantes Fluorescentes/química , Glutationa/análise , Polietilenoimina/química , Pontos Quânticos/química , Espectrometria de Fluorescência/métodos , Carbono/química , Linhagem Celular Tumoral , Humanos , Limite de Detecção , Microscopia Confocal , Neoplasias Gástricas/patologia
15.
J Photochem Photobiol B ; 197: 111504, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31228687

RESUMO

High disappointment rate of the ligament to hard tissue mending after the medical procedure has dependably been a testing issue in rotator cuff repair. Considering the elasticity of carbon dot decorated polyethylene (f-CDs-PE) and osteogenic movement of gold substituted hydroxyapatite (Au@HA) bioceramic, f-CDs-PE-Au@HA biocomposite coatings were created by an electrophoretic deposition method (EPD), the in vivo and in vitro bioactivity and cytocompatibility were researched. The physico-chemical properties of f-CDs-PE-Au@HA biocomposite coatings were characterized using fourier transform infra-red (FTIR) and X-Ray diffractometery (XRD). The morphology of the fabricated biocomposites was analyses via scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods. With a gamma-irradiation of f-CDs-PE-Au@HA biocomposite coating (BC2), the bond and multiplication of cells on biocomposite coating were improved. The specimen with a f-CDs-PE-Au@HA biocomposite (BC2) demonstrated a most noteworthy alkaline phosphatase activity articulation. The animal model consequences additionally show that the f-CDs-PE-Au@HA biocomposite (BC2) had great bioactive and cytocompatibility, which could develop the association of collagen and the arrangement of ligament and hard tissue. Expansion of the gamma-ray irradiation with f-CDs-PE-Au@HA biocomposite coating (BC2) at the tendon- hard tissue crossing point was exhibited to reinforce the mending entheses, increment hard tissue and tendon development and progress collagen association contrasted and control. The above outcomes have recommended that the progressive, implantable and solid stringy platforms built utilizing EPD extraordinary potential for enlargement of rotator cuff tears-recuperating.


Assuntos
Materiais Revestidos Biocompatíveis/química , Durapatita/química , Raios gama , Pontos Quânticos/química , Articulação do Ombro/patologia , Titânio/química , Artroplastia de Substituição , Densidade Óssea/efeitos da radiação , Carbono/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Materiais Revestidos Biocompatíveis/farmacologia , Colágeno Tipo I/metabolismo , Ouro/química , Humanos , Polietileno/química , Próteses e Implantes , Articulação do Ombro/diagnóstico por imagem , Tomografia Computadorizada por Raios X
16.
Food Chem ; 293: 387-395, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151626

RESUMO

The endogenous carbon quantum dots (CQDs) produced during food processing have potential uncertainty to human health. The objective of this study was to investigate the formation, biodistribution and cytotoxicity of CQDs in roasted Atlantic salmon (Salmo salar Linnaeus). The X-ray photoelectron spectroscopy (XPS) analysis showed that the CQDs were mainly composed of carbon, oxygen and nitrogen. The morphology, functional groups and optical properties were highly dependent on the roasting time. In vivo experiments in mice demonstrated that the CQDs distributed in the digestive tract, kidney, liver, and even brain, which indicated that they could cross the blood-brain barrier. The cell imaging results indicated that the CQDs could readily gain access to the normal rat kidney (NRK) cells, and caused autophagosome formation. The proportion of live cells decreased to 34.62% at 6 mg mL-1 of CQDs, and the energy generation route was changed from aerobic to glycolytic metabolism.


Assuntos
Pontos Quânticos/química , Pontos Quânticos/toxicidade , Salmo salar , Animais , Apoptose/efeitos dos fármacos , Autofagossomos/efeitos dos fármacos , Autofagossomos/metabolismo , Barreira Hematoencefálica/efeitos dos fármacos , Carbono/análise , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Culinária , Masculino , Camundongos Endogâmicos BALB C , Nitrogênio/análise , Oxigênio/análise , Espectroscopia Fotoeletrônica , Pontos Quânticos/metabolismo , Ratos , Distribuição Tecidual
17.
Chemistry ; 25(43): 10188-10196, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31192495

RESUMO

The fabrication of carbon dots and their doped forms by top-down chemical cleavage has attracted considerable attention in the efforts to meet the increasing demands for optoelectronic applications ranging from biosensing to electro- and photocatalysis. However, due to strong quantum confinement effects, the size decrease often leads to an increase in the band gap, even in the emission of deep-ultraviolet (DUV) light, which greatly limits their applications. Here, we report a facile hot-tailoring strategy for fabricating carbon nitride nanodots (CNDs) with redshifted intrinsic photoluminescent (PL) emission, compared with the pristine bulk precursor. It has been found that the different leaving abilities of the C,N-containing groups during the pyrolysis stage and the chemical passivation during the liquid-collection stage played vital roles. Due to the redshifted photoluminescence and other attractive features, the as-obtained CNDs were successfully applied in visual double text encryption with higher security and also in bioimaging with photostability superior to traditional dyes. This work highlights the great potential of the hot-tailoring method in modulating carbon-based nanostructures and offsetting band-gap widening as the size decreases.


Assuntos
Nitrilos/química , Pontos Quânticos/química , Sobrevivência Celular/efeitos dos fármacos , Humanos , Células MCF-7 , Microscopia Confocal , Espectroscopia Fotoeletrônica , Pirólise , Pontos Quânticos/toxicidade , Espectrometria de Fluorescência , Raios Ultravioleta
18.
Anal Chim Acta ; 1073: 45-53, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31146835

RESUMO

A novel and ultrasensitive electrochemiluminescent (ECL) bioassay has been developed for the detection of atrazine (ATZ), whereby bifunctional S, N-codoped carbon dots (S, N-CDs) and activated mesoporous bicarbons (BCs) have been innovatively integrated to synergistically amplify the ECL signal. When endogenous dissolved O2 is used as a coreactant, its sluggish reduction hinders the enhancement of ECL intensity of the luminophore, thus restricting its further application in bioanalysis. Here, bifunctional S, N-CDs severe as not only the ECL luminophore but the coreaction accelerator of dissolved O2 to generate more intermediates to boost the coreaction without using any other coreactant and coreaction accelerator. The as-formed nanoarchitectures of BCs possess enlarged surface area as the nanocarriers. They could provide adequate active sites for immobilization of tyrosinase (Tyr), which greatly prompts the ECL bioassay applications. Such a smart integration of bifunctional S, N-CDs, activated mesoporous BCs and the enzyme inhibition reaction achieves a unique and attractive high-performance signal-on ECL bioassay, realizing ultrasensitive detection of ATZ. Under the optimal condition, this bioassay exhibits two linear ranges, from 0.0001 to 0.01 µg L-1 and 0.01-20 µg L-1 with a detection limit of 0.08 ng L-1 at signal to noise ratio of 3. The as-fabricated assay is sensitive and economical, opening a new way for the enhancement of ECL signal output and a versatile strategy for ultrasensitive ECL bioanalysis.


Assuntos
Atrazina/análise , Técnicas Biossensoriais , Técnicas Eletroquímicas , Medições Luminescentes , Monofenol Mono-Oxigenase/química , Nanopartículas/química , Atrazina/metabolismo , Carbono/química , Monofenol Mono-Oxigenase/metabolismo , Nanopartículas/metabolismo , Tamanho da Partícula , Porosidade , Pontos Quânticos/química , Propriedades de Superfície
19.
Talanta ; 200: 9-14, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31036230

RESUMO

High-resolution observation of biological process is vital for biological researches and diagnosing diseases, which requires accurate diagnosis that involves coordinating imaging technologies such as fluorescence and magnetic resonance (MR). Nowadays, metal-based labels have been used for dual modality imaging. However, heavy metal ions are not environment-and organism-friendly. Therefore, it is a desirable to fabricate a metal-free label with fluorescence and MR properties. Herein, we synthesized boron-doped carbon dots (B-CDs) with dual modal properties through a one-pot solvothermal process. Compared with boron-free CDs, B-CDs exhibited apparent red-shift fluoresence emission, higher fluorescence intensity, and higher longitudinal relaxivity (r1 = 5.13 mM-1 s-1). It demonstrated that boron doping can enhance the fluorescence intensity of CDs, and maybe lead to form paramagnetic centers. The fluorescence and MR imaging of B-CDs make them a prospective label for clinical applications as a result of their oversimplified synthesis process, low cost, good biocompatibility and low toxicity. It will open a new window for building novel imaging labels.


Assuntos
Compostos de Boro/química , Carbono/química , Fluorescência , Corantes Fluorescentes/química , Imagem Óptica , Pontos Quânticos/química , Animais , Compostos de Boro/farmacologia , Carbono/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/farmacologia , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Camundongos , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
20.
Anal Chim Acta ; 1068: 52-59, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31072477

RESUMO

Early detection of carcinoembryonic antigen (CEA) is of great significance for the screening, diagnosis, monitoring and prognosis analysis of lung cancer. Herein, a novel fluorescence aptasensor with high signal-noise ratio (SNR) was constructed to achieve highly-sensitive detection of CEA relied upon the fluorescence resonance energy transfer (FRET) between near-infrared carbon dots (NIR-CDs) and gold nanorods (AuNRs). Initially, AuNRs@SiO2-Aptamer and NIR-CDs-DNA probe were prepared via the covalent bonding reaction between their corresponding carboxyl and amino groups, respectively. After DNA hybridization, the aptasensor was formed, meanwhile, the fluorescence of NIR-CDs was quenched by AuNRs@SiO2. Once CEA encountered the aptasensor, it would selectively combine with CEA aptamer to unwind the preformed DNA double-strand architecture thereby resulting in the NIR-CDs-DNA detach from the surface of AuNRs@SiO2. The attendant fluorescence recovery of NIR-CDs was linearly correlated with the concentration of CEA. According to this relationship, the NIR-CDs based "turn on" sensing system was constructed and exhibited prominent responses toward CEA in the concentration range of 0.1-5000 pg/mL and a relatively low detection limit (0.02 pg/mL). Moreover, it displayed high specificity against other biomarkers or proteins, good reproducibility and acceptable accuracy regarding human pleural effusion samples.


Assuntos
Aptâmeros de Nucleotídeos/química , Carbono/química , Antígeno Carcinoembrionário/análise , Fluorescência , Derrame Pleural/diagnóstico por imagem , Pontos Quânticos/química , Transferência Ressonante de Energia de Fluorescência , Ouro/química , Humanos , Nanotubos/química , Tamanho da Partícula , Propriedades de Superfície
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