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1.
J Chem Phys ; 151(14): 144706, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31615228

RESUMO

Quantum dot (QD) biological imaging and sensing applications often require surface modification with single-stranded deoxyribonucleic acid (ssDNA) oligonucleotides. Furthermore, ssDNA conjugation can be leveraged for precision QD templating via higher-order DNA nanostructures to exploit emergent behaviors in photonic applications. Use of ssDNA-QDs across these platforms requires compact, controlled conjugation that engenders QD stability over a wide pH range and in solutions of high ionic strength. However, current ssDNA-QD conjugation approaches suffer from limitations, such as the requirement for thick coatings, low control over ssDNA labeling density, requirement of large amounts of ssDNA, or low colloidal or photostability, restraining implementation in many applications. Here, we combine thin, multidentate, phytochelatin-3 (PC3) QD passivation techniques with strain-promoted copper-free alkyne-azide click chemistry to yield functional ssDNA-QDs with high stability. This process was broadly applicable across QD sizes (i.e., λem = 540, 560, 600 nm), ssDNA lengths (i.e., 10-16 base pairs, bps), and sequences (poly thymine, mixed bps). The resulting compact ssDNA-QDs displayed a fluorescence quenching efficiency of up to 89% by hybridization with complementary ssDNA-AuNPs. Furthermore, ssDNA-QDs were successfully incorporated with higher-order DNA origami nanostructure templates. Thus, this approach, combining PC3 passivation with click chemistry, generates ssDNA-PC3-QDs that enable emergent QD properties in DNA-based devices and applications.


Assuntos
DNA de Cadeia Simples/química , Nanocompostos/química , Pontos Quânticos/química , Alquinos/química , Azidas/química , Compostos de Cádmio/química , Química Click , Fluorescência , Ouro/química , Nanopartículas Metálicas/química , Hibridização de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Fitoquelatinas/química , Poli T/química , Compostos de Selênio/química , Sulfetos/química , Propriedades de Superfície , Compostos de Zinco/química
2.
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
3.
J Chem Phys ; 151(10): 105102, 2019 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-31521088

RESUMO

The interactions between nanoparticles (NPs) and proteins, cells, and tissues, broadly known as nano-bio interactions, depend on the NP size and shape and on the characteristics of the NP coating layer, such as density, thickness, and chemical makeup. The dependence of nano-membrane interactions on the design parameters of ultrasmall nanostructures is studied by computer simulations. Considered here are spheres, plates, rings, rods, tubes, and helices made up of either bare magnetite or passivated gold, interacting with charged or zwitterionic membranes. The analysis reveals a strong dependence on shape, size, and layer composition of various quantities that characterize the nano-bio behavior, including binding modes and affinities. This sensitivity can be exploited to design nanostructures that bind preferentially to membranes or that stabilize or disrupt membrane structural integrity. The method used here is general and not limited to the ultrasmall regime, so it can be adopted to study other nano-bio interactions systematically. The implications for the distribution of NPs in cells and tissues (biodistribution) and for passive and active transmembrane transport are discussed, both important processes in biomedicine.


Assuntos
Benzoatos/química , Glutationa/química , Ouro/química , Nanopartículas de Magnetita/química , Nanopartículas Metálicas/química , Compostos de Sulfidrila/química
4.
J Phys Chem Lett ; 10(20): 6105-6111, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31549842

RESUMO

Protein-protein interactions (PPIs) play a pivotal role in many biological processes. Discriminating functionally important well-defined protein-protein complexes formed by specific interactions from random aggregates produced by nonspecific interactions is therefore a critical capability. While there are many techniques which enable rapid screening of binding affinities in PPIs, there is no generic spectroscopic phenomenon which provides rapid characterization of the structure of protein-protein complexes. In this study we show that chiral plasmonic fields probe the structural order and hence the level of PPI specificity in a model antibody-antigen system. Using surface-immobilized Fab' fragments of polyclonal rabbit IgG antibodies with high specificity for bovine serum albumin (BSA), we show that chiral plasmonic fields can discriminate between a structurally anisotropic ensemble of BSA-Fab' complexes and random ovalbumin (OVA)-Fab' aggregates, demonstrating their potential as the basis of a useful proteomic technology for the initial rapid high-throughput screening of PPIs.


Assuntos
Fragmentos Fab das Imunoglobulinas/metabolismo , Imunoglobulina G/metabolismo , Nanoestruturas/química , Cimento de Policarboxilato/química , Soroalbumina Bovina/metabolismo , Animais , Anisotropia , Bovinos , Ouro/química , Fragmentos Fab das Imunoglobulinas/imunologia , Imunoglobulina G/imunologia , Ovalbumina/imunologia , Ovalbumina/metabolismo , Ligação Proteica , Coelhos , Soroalbumina Bovina/imunologia , Análise Espectral/métodos , Estereoisomerismo
5.
Chem Commun (Camb) ; 55(76): 11442-11445, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31486469

RESUMO

Plasmonic resonance energy transfer (PRET) from a Au nanosphere (AuNS) to a quantum dot (QD) is discovered at the single particle level. A homogenous immunoassay based on this PRET is verified using a prostate specific antigen (PSA) as an example. The limit of detection of the PSA is determined to be 0.2 fM.


Assuntos
Técnicas Biossensoriais , Transferência Ressonante de Energia de Fluorescência , Ouro/química , Imunoensaio , Nanopartículas Metálicas/química , Pontos Quânticos/química , Albuminas/análise , Aminoácidos/sangue , Animais , Ânions/sangue , Biomarcadores/sangue , Cátions/sangue , Galinhas , Humanos
6.
Chem Commun (Camb) ; 55(82): 12352-12355, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31559405

RESUMO

We report a new biofunctionalized nanoplatform based on hyaluronic acid-coated gold-nano-dot-decorated hollow carbon nanospheres (AuHCNs-HA) for microRNA imaging in living cells. Importantly, the HA-coated nanoplatform could be internalized into target cells via CD44 receptor-mediated endocytosis. It can be further applied for intracellular miR-21 imaging in CD44-positive colorectal cancer cells.


Assuntos
Neoplasias Colorretais/metabolismo , Ouro/química , Nanopartículas Metálicas/química , MicroRNAs/análise , Imagem Óptica/métodos , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/química , Imagem Óptica/instrumentação , Tamanho da Partícula , Porosidade , Propriedades de Superfície
7.
Chem Commun (Camb) ; 55(77): 11543-11546, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31490483

RESUMO

In this work, a simulated enzyme inhibition-based strategy was transplanted from natural peroxidase-based sensing methods for colorimetric nanoperoxidase-based biothiol detection. This work might provide some new perspectives for the construction and biomimetic regulation of mimicked biological signalling systems based on nanoperoxidases.


Assuntos
Corantes Fluorescentes/química , Glutationa/análise , Mercúrio/química , Nanopartículas Metálicas/química , Peroxidases/química , Pontos Quânticos/química , Compostos de Sulfidrila/análise , Materiais Biomiméticos/química , Técnicas Biossensoriais/métodos , Carbono/química , Catálise , Colorimetria/métodos , Ouro/química , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Oxirredução , Peroxidases/antagonistas & inibidores , Propriedades de Superfície
8.
Chem Commun (Camb) ; 55(67): 9967-9970, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31367705

RESUMO

Herein, a seesaw ratiometric (SR) probe is designed which integrates fluorescence and surface enhanced Raman scattering (SERS) technology. Fluorescence imaging enables tracking of the spatiotemporal dynamic behaviour of telomerase. Meanwhile, SERS reverse ratiometric measurement can enable sensitive detection of telomerase activity in single living cells.


Assuntos
Corantes/química , Imagem Óptica/métodos , Análise de Célula Única/métodos , Análise Espectral Raman/métodos , Telomerase/metabolismo , DNA/química , Transferência Ressonante de Energia de Fluorescência/métodos , Ouro/química , Humanos , Células MCF-7 , Nanopartículas Metálicas/química
9.
Int J Nanomedicine ; 14: 4991-5015, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31371943

RESUMO

Purpose: This study evaluates the cytotoxicity of AuNPs coated with polyallylamine (AuNPs-PAA) and conjugated or not to the epidermal growth factor receptor (EGFR)-targeting antibody Cetuximab (AuNPs-PAA-Ctxb) in normal human kidney (HK-2), liver (THLE-2) and microvascular endothelial (TIME) cells, and compares it with two cancer cell lines that are EGFR-overexpressing (A431) or EGFR-negative (MDA-MB-453). Results: Conjugation of Cetuximab to AuNPs-PAA increased the AuNPs-PAA-Ctxb interactions with cells, but reduced their cytotoxicity. TIME cells exhibited the strongest reduction in viability after exposure to AuNPs-PAA(±Ctxb), followed by THLE-2, MDA-MB-453, HK-2 and A431 cells. This cell type-dependent sensitivity was strongly correlated to the inhibition of thioredoxin reductase (TrxR) and glutathione reductase (GR), and to the depolarization of the mitochondrial membrane potential. Both are suggested to initiate apoptosis, which was indeed detected in a concentration- and time-dependent manner. The role of oxidative stress in AuNPs-PAA(±Ctxb)-induced cytotoxicity was demonstrated by co-incubation of the cells with N-acetyl L-cysteine (NAC), which significantly decreased apoptosis and mitochondrial membrane depolarization. Conclusion: This study helps to identify the cells and tissues that could be sensitive to AuNPs and deepens the understanding of the risks associated with the use of AuNPs in vivo.


Assuntos
Antioxidantes/metabolismo , Ouro/química , Nanopartículas Metálicas/química , Acetilcisteína/farmacologia , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 7/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cetuximab/farmacologia , Endocitose/efeitos dos fármacos , Glutationa Redutase/metabolismo , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Nanopartículas Metálicas/ultraestrutura , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Tamanho da Partícula , Poliaminas/química , Substâncias Protetoras/farmacologia , Eletricidade Estática , Tiorredoxina Dissulfeto Redutase/metabolismo
10.
Int J Nanomedicine ; 14: 5125-5133, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31371951

RESUMO

Purpose: The frequent usage of various lighting screens has made dry eye syndrome an increasingly serious phenomenon. To relieve this global problem, we have developed a photothermal conversion hydrogel based mini-eye patch. Methods: Gold nanoparticles (GNRs) were synthesized by a seed-mediated method, and then used as the inner cores to grow palladium (Pd) shell by PdCl42-reduction. Then, gelatin was added to prepare GNRs @ Pd hydrogel eye patch by genipin cross-linking. We implanted temperature sensitive ink (complex composed of amino resin and styrene maleic anhydride copolymer) in the eye patch, which could change color at different temperatures. Heating performance of the eye patch was accessed with an infrared temperature profile and the circulating temperature experiment. The safety assessment of the eye patch was conducted by H&E staining of the mouse's eyelid skin and CCK-8 assay. A Keratograph 5M noninvasive ocular surface analyzer was used to assess the impact of eye patches on dry eyes. Results: It was found that GNRs @ Pd hydrogel eye patches could sense various visible light and responded by heating up spontaneously. Results from the CCK-8 assay and H&E staining showed that the eye patch has good safety performance. Measurements of the first noninvasive tear break-up time (NITBUT), the average NITBUT, the tear meniscus height (TMH), combined with red eye analysis, further demonstrated the patch's eye-protective properties. Conclusion: After being pasted to the lacrimal gland, the hydrogel patch converted various light irradiations into heat and stimulated the lacrimal gland to produce more tears to relieve dry eye. The built-in temperature-sensitive ink can play an important role in warning people of their excessive eye usage. Because this recyclable strategy does not interfere with normal eye use, it is thus more environmentally friendly and convenient than ordinary infrared eyewear.


Assuntos
Síndromes do Olho Seco/terapia , Olho/patologia , Hidrogéis/química , Luz , Temperatura Ambiente , Adolescente , Adulto , Animais , Linhagem Celular , Feminino , Ouro/química , Humanos , Masculino , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Camundongos , Coelhos , Ratos Sprague-Dawley , Adulto Jovem
11.
Int J Nanomedicine ; 14: 5147-5157, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31371953

RESUMO

Background: Kaempferol (K) is a recognized anticancer drug that can conjugate with small-size gold nanoclusters (AuNCs). Materials and methods: K-AuNCs were synthesized and their use as an anticancer drug was explored using A549 lung cancer cells. Colony formation and cell migration assays were carried out. The morphology of the K-AuNCs treated A549 cells was explored using bio-atomic force microscopy. Results: The K-AuNCs were 1-3 nm in diameter and emitted strong fluorescent at 650 nm following excitation at 550 nm. The stretching and bending nature of the K-AuNCs were analyzed by the Fourier transform infrared spectroscopy. The presence of kaempferol in the AuNCs were confirmed by the PL spectroscopy. Conclusion: The synthesized K-AuNCs mainly targeted and damaged the nuclei of the cancer cells. This composite nanocluster was less toxicity to the normal human cell and higher toxicity to the A549 lunch cancer cell and these material is potential for anticancer drug delivery and bio imaging applications.


Assuntos
Antineoplásicos/uso terapêutico , Ouro/química , Quempferóis/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Nanopartículas Metálicas/química , Células A549 , Antineoplásicos/química , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/patologia , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Humanos , Quempferóis/farmacologia , Nanopartículas Metálicas/toxicidade , Nanopartículas Metálicas/ultraestrutura , Fenômenos Ópticos , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
12.
Int J Nanomedicine ; 14: 5369-5379, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31409993

RESUMO

Purpose: Photothermal therapy (PTT) exploits the light-absorbing properties of nanomaterials such as silica-gold nanoshells (NS) to inflict tumor death through local hyperthermia. However, in in vivo studies of PTT, the heat distribution is often found to be heterogeneous throughout the tumor volume, which leaves parts of the tumor untreated and impairs the overall treatment outcome. As this challenges PTT as a one-dose therapy, this study here investigates if giving the treatment repeatedly, ie, fractionated PTT, increases the efficacy in mice bearing subcutaneous tumors. Methods: The NS heating properties were first optimized in vitro and in vivo. Two fractionated PTT protocols, consisting of two and four laser treatments, respectively, were developed and applied in a murine subcutaneous colorectal tumor model. The efficacy of the two fractionated protocols was evaluated both by longitudinal monitoring of tumor growth and, at an early time point, by positron emission tomography (PET) imaging of 18F-labeled glucose analog 18F-FDG. Results: Overall, there were no significant differences in tumor growth and survival between groups of mice receiving single-dose PTT and fractionated PTT in our study. Nonetheless, some animals did experience inhibited tumor growth or even complete tumor disappearance due to fractionated PTT, and these animals also showed a significant decrease in tumor uptake of 18F-FDG after therapy. Conclusion: This study only found an effect of giving PTT to tumors in fractions compared to a single-dose approach in a few animals. However, many factors can affect the outcome of PTT, and reliable tools for optimization of treatment protocol are needed. Despite the modest treatment effect, our results indicate that 18F-FDG PET/CT imaging can be useful to guide the number of treatment sessions necessary.


Assuntos
Hipertermia Induzida , Fototerapia , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Relação Dose-Resposta à Radiação , Feminino , Glicerol/química , Ouro/química , Temperatura Alta , Raios Infravermelhos , Camundongos Endogâmicos BALB C , Nanoconchas/química , Nanoconchas/ultraestrutura , Neoplasias/patologia , Neoplasias/terapia , Tomografia por Emissão de Pósitrons , Dióxido de Silício/química , Resultado do Tratamento , Carga Tumoral
13.
Chem Pharm Bull (Tokyo) ; 67(8): 872-876, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31366835

RESUMO

A gold-catalyzed introduction of various terminal alkynes to acetals was investigated. Extensive optimization of the reaction conditions revealed that thermally stable cationic gold catalysts bearing bulky ligands such as 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene 3-1H-benzo[d][1,2,3]triazolyl gold trifluoromethanesulfonate (IPrAu(BTZ-H)OTf) were particularly suitable for the reaction. Additionally, significant solvent effects were observed. Ether solvents such as tetrahydrofuran (THF), cyclo pentyl methyl ether (CPME), and 1,4-dioxane were effective for the reaction. Studies on the scope of substrates and alkynes indicated that various alkynes and acetals were feasible to provide a wide range of propargylic ethers.


Assuntos
Acetais/química , Alquinos/química , Éteres/síntese química , Ouro/química , Alquinos/síntese química , Éteres/química , Estrutura Molecular
15.
Chem Commun (Camb) ; 55(69): 10288-10291, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31396601

RESUMO

A simple nanopore modification and sensing strategy was developed for the detection of miRNAs. This preparation and sensing approach provides a quick, simple and facile tool for the detection of specific biomolecules with high sensitivity and selectivity, and may find a wide range of applications in bio-analysis.


Assuntos
Ouro/química , Ácidos Nucleicos Imobilizados/química , MicroRNAs/análise , Nanoporos/ultraestrutura , Técnicas Biossensoriais/instrumentação , Desenho de Equipamento , Hibridização de Ácido Nucleico
16.
Chem Commun (Camb) ; 55(66): 9865-9868, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31364624

RESUMO

Au hydrogel with a well-defined nanowire network was rationally designed through one-step dopamine-induced self-assembly. Due to the porous nanostructure along with the polydopamine induced accumulation and interfacial electron transfer effects, the resulting Au hydrogel nanozyme exhibits enhanced glucose oxidase-like activity and peroxidase-like activity, with a biomimetic cascade catalysis.


Assuntos
Biomimética , Dopamina/química , Glucose Oxidase/química , Ouro/química , Hidrogéis/química , Nanopartículas Metálicas/química , Peroxidase/química , Catálise , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Oxirredução
17.
Phys Chem Chem Phys ; 21(33): 18352-18362, 2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31402363

RESUMO

Graphene coated gold nanoparticles (GGNPs) have attracted great attention in recent years because of their high thermal stability and unique optical properties. In this paper, we study photothermal properties of GGNPs using the Mie and Gans theories combined with the Pennes bioheat equation. The effect of various sizes and different shapes of GGNPs such as nanosphere, nanorod and nanodisc are taken into account. The extinction efficiency and temperature distribution in tumor tissue show that graphene coated gold nanorods, because of the high temperature rise during laser irradiation, are more suitable candidates for photothermal therapy (PTT) applications. Also, we show that the extinction peak of graphene coated gold nanorods can be adjusted in the biological windows by increasing the graphene shell thickness and/or by changing their aspect ratio. Finally, we investigated the effect of the number of graphene layers upon the temperature rise in the tumor and found that the temperature rise increases with increasing number of graphene layers. Our findings introduce a new class of nanoagents which can be used in PTT applications.


Assuntos
Ouro/química , Grafite/química , Nanopartículas Metálicas/química , Nanotubos/química , Fototerapia/métodos
18.
Int J Nanomedicine ; 14: 4413-4428, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31417252

RESUMO

Background: As part of our continuing quest to enhance the efficacy of bioactive phytochemicals in cancer therapy, we report an innovative green nanotechnology approach toward the use of resveratrol for the production of biocompatible resveratrol-conjugated gold nanoparticles (Res-AuNPs). Our overarching aim is to exploit the inherent pro-apoptotic properties of gold nanoparticles (AuNPs) through synergistic anti-tumor characteristics of resveratrol, with the aim of developing a new class of green nanotechnology-based phytochemical-embedded AuNPs for applications in oncology. Method: Resveratrol was used to reduce Au3+ to Au0 for the synthesis of Res-AuNPs at room temperature and gum arabic (GA) was used to further encapsulate the nanoparticulate surface to increase the overall stability of the AuNPs. This comprehensive study involves the synthesis, full characterization and in vitro stability of Res-AuNPs in various biological media for their ultimate applications as anti-cancer agents against human breast (MDAMB-231), pancreatic (PANC-1) and prostate (PC-3) cancers. Results: This strategy to systematically increase the corona of resveratrol on AuNPs, in order to gain insights into the interrelationship of the phytochemical corona on the overall anti-tumor activities of Res-AuNPs, proved successful. The increased resveratrol corona on Res-AuNPs showed superior anti-cancer effects, attributed to an optimal cellular uptake after 24-hour incubation, while GA provided a protein matrix support for enhanced trans-resveratrol loading onto the surface of the AuNPs. Conclusion: The approach described in this study harnesses the benefits of nutraceuticals and nanoparticles toward the development of Res-AuNPs. We provide compelling evidence that the increased corona of resveratrol on AuNPs enhances the bioavailability of resveratrol so that therapeutically active species can be optimally available in vivo for applications in cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Ouro/química , Nanopartículas Metálicas/química , Neoplasias Pancreáticas/patologia , Neoplasias da Próstata/patologia , Resveratrol/farmacologia , Linhagem Celular Tumoral , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Endocitose , Feminino , Humanos , Concentração Inibidora 50 , Masculino , Nanopartículas Metálicas/ultraestrutura , Tamanho da Partícula , Polifenóis/química , Polifenóis/farmacologia , Resveratrol/química , Espectrofotometria Ultravioleta , Resultado do Tratamento
19.
J Agric Food Chem ; 67(34): 9658-9666, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31381330

RESUMO

The biomimetic enzyme-linked immunosorbent assay (BELISA) is widely used for detection of small-molecule compounds as a result of low cost and reagent stability of molecularly imprinted polymers (MIPs). However, enzyme labels used in BELISA still suffer some drawbacks, such as high production cost and limited stability. To overcome the drawbacks, a biomimetic nanozyme-linked immunosorbent assay (BNLISA) based on MIPs and nanozyme labels was first proposed. For nanozyme labels, platinum nanoparticles (PtNPs) acted as peroxidase by catalyzing the oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) into an ideal surface-enhanced Raman scattering (SERS) marker. Blue TMB2+ and bovine serum albumin (BSA)-hapten showed superior selectivity when competing with targets for binding sites on MIPs, named the Pt@BSA-hapten probe. The BNLISA method was employed to detect triazophos with a limit of detection of 1 ng mL-1 via colorimetric and SERS methods. Replacing traditional enzymes with nanozymes for combination with MIPs may bring about a new prospect for other compound analyses.


Assuntos
Colorimetria/métodos , Organotiofosfatos/análise , Praguicidas/análise , Análise Espectral Raman/métodos , Triazóis/análise , Benzidinas/química , Materiais Biomiméticos/química , Colorimetria/instrumentação , Frutas/química , Ouro/química , Imunoadsorventes/química , Nanopartículas Metálicas/química , Platina/química , Pyrus/química , Sensibilidade e Especificidade , Análise Espectral Raman/instrumentação , Poluentes Químicos da Água/análise
20.
Chem Commun (Camb) ; 55(71): 10571-10574, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31417999

RESUMO

A portable dual-mode sensing platform based on a self-standing TiO2 nanotube membrane is developed for simultaneously performing both qualitative analysis by the naked eye and quantitative analysis by ionic current. This dual-mode diagnosis strategy exhibits a high performance in telomerase detection in urine specimens from patients with bladder cancer.


Assuntos
Nanotubos/química , Telomerase/urina , Titânio/química , Neoplasias da Bexiga Urinária/diagnóstico , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Cor , Ouro/química , Humanos , Membranas Artificiais , Nanopartículas Metálicas/química , Prata/química , Neoplasias da Bexiga Urinária/urina
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