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1.
Proc Natl Acad Sci U S A ; 118(4)2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33468677

RESUMO

We have studied the role of protein dynamics in chemical catalysis in the enzyme dihydrofolate reductase (DHFR), using a pump-probe method that employs pulsed-laser photothermal heating of a gold nanoparticle (AuNP) to directly excite a local region of the protein structure and transient absorbance to probe the effect on enzyme activity. Enzyme activity is accelerated by pulsed-laser excitation when the AuNP is attached close to a network of coupled motions in DHFR (on the FG loop, containing residues 116-132, or on a nearby alpha helix). No rate acceleration is observed when the AuNP is attached away from the network (distal mutant and His-tagged mutant) with pulsed excitation, or for any attachment site with continuous wave excitation. We interpret these results within an energy landscape model in which transient, site-specific addition of energy to the enzyme speeds up the search for reactive conformations by activating motions that facilitate this search.


Assuntos
Nanopartículas Metálicas/química , Modelos Moleculares , Tetra-Hidrofolato Desidrogenase/química , Catálise , Domínio Catalítico/efeitos da radiação , Ouro/química , Calefação/efeitos adversos , Cinética , Nanopartículas Metálicas/efeitos da radiação , Conformação Proteica/efeitos da radiação , Tetra-Hidrofolato Desidrogenase/ultraestrutura
2.
ACS Appl Mater Interfaces ; 12(51): 56874-56885, 2020 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-33326207

RESUMO

Radiotherapy is the main treatment for cancer patients. A major concern in radiotherapy is the radiation resistance of some tumors, such as human nonsmall cell lung cancer. However, the radiation dose delivered to the tumors is often limited by the possibility of collateral damage to surrounding healthy tissues. A new and efficient gadolinium-based nanoparticle, AGuIX, has recently been developed for magnetic resonance imaging-guided radiotherapy and has been proven to act as an efficient radiosensitizer. The amplified radiation effects of AGuIX nanoparticles appear to be due to the emission of low-energy photoelectrons and Auger electron interactions. We demonstrated that AGuIX nanoparticles exacerbated radiation-induced DNA double-strand break damage and reduced DNA repair in the H1299 nonsmall cell lung cancer cell line. Furthermore, we observed a significant improvement in tumor cell damage and growth suppression, under radiation therapy, with the AGuIX nanoparticles in a H1299 mouse xenograft model. This study paves the way for research into the radiosensitization mechanism of AGuIX nanoparticles and provides a scientific basis for the use of AGuIX nanoparticles as radiosensitizing drugs.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Nanopartículas Metálicas/uso terapêutico , Radiossensibilizantes/uso terapêutico , Animais , Antineoplásicos/química , Antineoplásicos/efeitos da radiação , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Gadolínio/química , Gadolínio/efeitos da radiação , Humanos , Pulmão/patologia , Neoplasias Pulmonares/patologia , Masculino , Nanopartículas Metálicas/química , Nanopartículas Metálicas/efeitos da radiação , Camundongos Nus , Radiação Ionizante , Radiossensibilizantes/química , Radiossensibilizantes/efeitos da radiação , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Nat Commun ; 11(1): 4530, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32913195

RESUMO

Various cancer cells have been demonstrated to have the capacity to form plasmonic gold nanoparticles when chloroauric acid is introduced to their cellular microenvironment. But their biomedical applications are limited, particularly considering the millimolar concentrations and longer incubation period of ionic gold. Here, we describe a simplistic method of intracellular biomineralization to produce plasmonic gold nanoparticles at micromolar concentrations within 30 min of application utilizing polyethylene glycol as delivery vector for ionic gold. We have characterized this process for intracellular gold nanoparticle formation, which progressively accumulates proteins as the ionic gold clusters migrate to the nucleus. This nano-vectorized application of ionic gold emphasizes its potential biomedical opportunities while reducing the quantity of ionic gold and required incubation time. To demonstrate its biomedical potential, we further induce in-situ biosynthesis of gold nanoparticles within MCF7 tumor mouse xenografts which is followed by its photothermal remediation.


Assuntos
Cloretos/administração & dosagem , Portadores de Fármacos/química , Compostos de Ouro/administração & dosagem , Ouro/química , Nanopartículas Metálicas/química , Neoplasias/tratamento farmacológico , Nanomedicina Teranóstica/métodos , Animais , Biomineralização/efeitos da radiação , Feminino , Ouro/efeitos da radiação , Humanos , Hipertermia Induzida/métodos , Íons , Células MCF-7 , Nanopartículas Metálicas/efeitos da radiação , Camundongos , Fotoquimioterapia/métodos , Polietilenoglicóis/química , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Proc Natl Acad Sci U S A ; 117(27): 15473-15481, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32571948

RESUMO

The development of sustainable methods for the degradation of pollutants in water is an ongoing critical challenge. Anthropogenic organic micropollutants such as pharmaceuticals, present in our water supplies in trace quantities, are currently not remediated by conventional treatment processes. Here, we report an initial demonstration of the oxidative degradation of organic micropollutants using specially designed nanoparticles and visible-wavelength sunlight. Gold "Janus" nanorods (Au JNRs), partially coated with silica to enhance their colloidal stability in aqueous solutions while also maintaining a partially uncoated Au surface to facilitate photocatalysis, were synthesized. Au JNRs were dispersed in an aqueous solution containing peroxydisulfate (PDS), where oxidative degradation of both simulant and actual organic micropollutants was observed. Photothermal heating, light-induced hot electron-driven charge transfer, and direct electron shuttling under dark conditions all contribute to the observed oxidation chemistry. This work not only provides an ideal platform for studying plasmonic photochemistry in aqueous medium but also opens the door for nanoengineered, solar-based methods to remediate recalcitrant micropollutants in water supplies.


Assuntos
Nanopartículas Metálicas/efeitos da radiação , Fotólise/efeitos da radiação , Luz Solar , Poluentes Químicos da Água/química , Poluição Química da Água/prevenção & controle , Ouro/química , Ouro/efeitos da radiação , Nanopartículas Metálicas/química , Nanotecnologia/métodos , Nanotubos/química , Nanotubos/efeitos da radiação , Compostos Orgânicos/química , Compostos Orgânicos/toxicidade , Oxirredução/efeitos da radiação , Dióxido de Silício/química , Dióxido de Silício/efeitos da radiação , Água/química , Poluentes Químicos da Água/toxicidade
5.
J Chem Phys ; 152(12): 124712, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32241129

RESUMO

Laser illuminated gold nanoparticles (AuNPs) efficiently absorb light and heat up the surrounding medium, leading to versatile applications ranging from plasmonic catalysis to cancer photothermal therapy. Therefore, an in-depth understanding of the thermal, optical, and electron induced reaction pathways is required. Here, the electrophilic DNA nucleobase analog 5-Bromouracil (BrU) has been used as a model compound to study its decomposition in the vicinity of AuNPs illuminated with intense ns laser pulses under various conditions. The plasmonic response of the AuNPs and the concentration of BrU and resulting photoproducts have been tracked by ultraviolet and visible (UV-Vis) spectroscopy as a function of the irradiation time. A kinetic model has been developed to determine the reaction rates of two parallel fragmentation pathways of BrU, and their dependency on laser fluence and adsorption on the AuNP have been evaluated. In addition, the size and the electric field enhancement of the decomposed AuNPs have been determined by atomic force microscopy and finite domain time difference calculations, respectively. A minor influence of the direct photoreaction and a strong effect of the heating of the AuNPs have been revealed. However, due to the size reduction of the irradiated AuNPs, a trade-off between laser fluence and plasmonic response of the AuNPs has been observed. Hence, the decomposition of the AuNPs might be limiting the achievable temperatures under irradiation with several laser pulses. These findings need to be considered for an efficient design of catalytic plasmonic systems.


Assuntos
Bromouracila/química , Nanopartículas Metálicas/química , Ouro/química , Ouro/efeitos da radiação , Cinética , Lasers , Luz , Nanopartículas Metálicas/efeitos da radiação
6.
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
7.
J Photochem Photobiol B ; 205: 111807, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32120182

RESUMO

The formation of the carbon­carbon bond in the synthetic chemistry explored in many ways. Suzuki-cross coupling is one of the ways to make bonds between two carbon atoms of similar molecules or different molecules. CC bond was successfully formed between two aryl rings of aryl halides and phenylboronic acid at room temperature and atmospheric pressure under the visible illuminance. In this work we report, an in-situ synthesis of silver nanoparticles doped TiO2 nanoparticles (NPs) and studied its catalytic activity as an eco-friendly, simple, recyclable and efficient catalyst for one-pot Suzuki-coupling of bromoaryl with phenylboronic acid under visible light. Only, 45 mg of the catalyst resulted in a 98% conversion of p-ethyl bromobenzene with a 97% yield of p-ethyl biphenyl using toluene as the solvent in the presence of visible light at atmospheric pressure. The electron-donating groups (e.g., ethyl group) substituted bromobenzene resulted in the maximum yields than that of the substitution with the electron-withdrawing groups. The catalyst shown significant catalytic activity up to seven recycling runs without any loss. The doping of silver nanoparticles boosted the catalytic activity at titanium dioxide surface as well as inside the pores. The high surface area of the semiconductor support provides the sites for accommodated silver nanoparticles and shows enhanced reactivity towards the coupling reaction of bromoaryl with phenylboronic acid. The as-synthesized catalyst was thoroughly characterized by XRD, TEM, EDX, XPS, FTIR, TGA, UV-vis, Raman and BET analysis. The high recyclability of the photocatalyst remarked the footprints in the CC coupling reactions.


Assuntos
Ácidos Borônicos/química , Hidrocarbonetos Bromados/química , Nanopartículas Metálicas/química , Prata/química , Titânio/química , Catálise , Luz , Nanopartículas Metálicas/efeitos da radiação , Prata/efeitos da radiação , Titânio/efeitos da radiação
8.
J Photochem Photobiol B ; 205: 111823, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32120184

RESUMO

The current scenario of water resources shows the dominance of pollution caused by the draining of industrial effluents. The polluted waters have resulted in severe health and environmental hazards urging for a suitable alternative to resolve the implications. Various physical and chemical treatment steps currently in use for dye effluent treatment are more time consuming, cost-intensive, and less effective. Alternatively, nanoparticles due to their excellent surface properties and chemical reactivity have emerged as a better solution for dye removal and degradation. In this regard, the potential of silver nanoparticles in dye effluent treatment was greatly explored. Efforts were taken to unravel the kinetics and statistical optimization of the treatment conditions for the efficient removal of dyes. In addition, the role of silver nanocomposites has also experimented with colossal success. On the contrary, studies have also recognized the mechanisms of silver nanoparticle-mediated toxicity even at deficient concentrations and their deleterious biological effects when present in treated water. Hence, the fate of the silver nanoparticles released into the treated water and sludge, contaminating the soil, aquatic environment, and underground water is of significant concern. This review summarizes the current state of knowledge regarding the use of silver nanoparticles and silver-based nanocomposites in effluent treatment and comprehends the recent research on mitigation of silver nanoparticle-induced toxicity.


Assuntos
Corantes/química , Nanopartículas Metálicas , Prata , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Adsorção , Animais , Catálise , Humanos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/efeitos da radiação , Nanopartículas Metálicas/toxicidade , Fotólise , Prata/química , Prata/efeitos da radiação , Prata/toxicidade , Águas Residuárias/química
9.
Talanta ; 212: 120797, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32113559

RESUMO

We report here sensitive photoelectrochemical immunosensing of Staphylococcus aureus (S. aureus) using ZnS-Ag2S/polydopamine (PDA) as a novel photoelectric material and Cu2O as the peroxidase mimic tag. ZnS-Ag2S heterojunctions were prepared on indium tin oxide (ITO) via electrodeposition of ZnS nanoparticles, followed by silver ion exchange. To prepare a PDA/ZnS-Ag2S/ITO, the ZnS-Ag2S/ITO electrode was coated with PDA by self-polymerization of dopamine. The photocurrent of the PDA/ZnS-Ag2S/ITO is 1.55 times that of the ZnS-Ag2S/ITO and 7.87 times that of the ZnS/ITO, indicating a high-performance photoelectric material. A sandwiched-type photoelectrochemical immunosensor was constructed by using PDA/ZnS-Ag2S/ITO as the photoelectrode and Cu2O nanocubes as the labels. Cu2O nanocubes can serve as peroxidase mimic to generate catalytic precipitates on the immunoelectrodes, and both the Cu2O nanocubes and the generated precipitates can decrease the photocurrents of the immunoelectrodes, so a photoelectrochemical immunosensor for detecting S. aureus was constructed, showing a linear range between 10 and 107 CFU mL-1 and a low detection limit of 2 CFU mL-1. Owing to the signal amplification of Cu2O labeling, the sensitivity of the Cu2O-labeled immunosensor is 4 times that of a label-free immunosensor for detecting S. aureus, and the detection limit (2 CFU mL-1) is lower than that of a label-free immunosensor (10 CFU mL-1). This work not only provides a new and efficient photoelectric material but also demonstrated an efficient signal-amplification strategy for photoelectrochemical biosensing.


Assuntos
Cobre/química , Imunoensaio/métodos , Indóis/química , Nanopartículas Metálicas/química , Polímeros/química , Staphylococcus aureus/isolamento & purificação , Anticorpos Imobilizados/imunologia , Técnicas Biossensoriais/métodos , Catálise , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Indóis/efeitos da radiação , Luz , Limite de Detecção , Nanopartículas Metálicas/efeitos da radiação , Polímeros/efeitos da radiação , Compostos de Prata/química , Compostos de Prata/efeitos da radiação , Staphylococcus aureus/imunologia , Sulfetos/química , Sulfetos/efeitos da radiação , Compostos de Estanho/química , Compostos de Zinco/química , Compostos de Zinco/efeitos da radiação
10.
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
11.
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 , Ciprofloxacina/química , Nanopartículas Metálicas/química , Molibdênio/química , Nanoestruturas/química , Nitrilas/química , Antibacterianos/metabolismo , Catálise , Ciprofloxacina/metabolismo , Luz , Nanopartículas Metálicas/efeitos da radiação , Molibdênio/efeitos da radiação , Nanoestruturas/efeitos da radiação , Nitrilas/efeitos da radiação , Processos Fotoquímicos , Fotólise
12.
J Mater Chem B ; 7(42): 6630-6642, 2019 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-31591609

RESUMO

Copper-cysteamine (Cu-Cy) is a novel sensitizer that can be excited by ultraviolet (UV) light, microwave (MW), ultrasound, and X-rays to generate highly toxic reactive oxygen species (ROS) for cancer cell destruction. The purpose of this study is to present a facile method for the synthesis of Cu-Cy nanoparticles. Interestingly, we were able to decrease both the stirring and heating time by about 24 and 6 times, respectively, thus making Cu-Cy nanoparticles more economical than what was reported before. 1,4-Diazabicylo[2.2.2]octane (DABCO), a well-known singlet oxygen quencher, showed that the majority of ROS produced by Cu-Cy nanoparticles upon UV and MW exposure were singlet oxygen. Moreover, ROS generated by Cu-Cy nanoparticles upon UV and MW exposure were confirmed by a known ROS tracking agent, dihydrorhodamine 123, further serving as an additional piece of evidence that Cu-Cy is a promising ROS generating agent to destroy cancer cells as well as bacteria or viruses by a radical therapeutic approach. Additionally, for the first time, the hydroxyl radical (˙OH) produced by Cu-Cy nanoparticles upon MW activation was proved by a photoluminescence (PL) technique using coumarin as a probe molecule. Remarkably, newly synthesized nanoparticles were found to be much more effective for producing ROS and killing cancer cells, suggesting that the new method may have increased the reactivity of the Cu-Cy nanoparticles due to an overall size reduction. Overall, the new method not only reduced the synthesis time but also enhanced the effectiveness of Cu-Cy nanoparticles for photodynamic therapy.


Assuntos
Antineoplásicos/farmacologia , Nanopartículas Metálicas/química , Neoplasias/metabolismo , Fármacos Fotossensibilizantes/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/efeitos da radiação , Linhagem Celular Tumoral , Cobre/química , Cobre/efeitos da radiação , Cisteamina/química , Cisteamina/efeitos da radiação , Humanos , Radical Hidroxila/metabolismo , Nanopartículas Metálicas/efeitos da radiação , Micro-Ondas , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/efeitos da radiação , Oxigênio Singlete/metabolismo , Raios Ultravioleta
13.
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
14.
Anal Chem ; 91(22): 14611-14617, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31660734

RESUMO

Photoelectrochemical (PEC) techniques are of fundamental and practical importance, and they have been widely used for solar energy conversion and experimental protection. Besides these important applications, an emerging and fast developing PEC application of PEC bioanalysis is receiving more attention from both academic and clinic communities. However, the typical PEC biosensing is still limited under illumination of ultraviolet and visible (UV/vis) light, which hampers its in vivo detection in deep tissues. Expanding the optical absorption wavelength of photoelectrodes from the UV/vis light region into the near-infrared (NIR) light region is highly desirable due to its deep tissue penetrability and minimal invasiveness for organisms, but the exploration of a facile strategy to implement efficient NIR absorption with biocompatible materials is still a big challenge. Herein, under the guidance of theorical calculations, we propose a strategy through modulation of bulk/surface defects and decoration of Au nanoparticles on TiO2 nanotube photonic crystals to implement efficient NIR response and thus successfully realize sensitive and selective PEC detection of antibiotics in real bio- and experimental-samples under NIR illumination. In addition, we first implement the in vivo PEC detection under illumination of NIR light. We have faith that this new NIR photoelectric responsive strategy will provide a broad platform for detection of life-related biomolecules in deep tissues or even in vivo for real-time measurement and shed light on the intrinsic connections between biomarkers and clinical diseases.


Assuntos
Antibacterianos/análise , Ouro/química , Nanopartículas Metálicas/química , Nanotubos/química , Tetraciclina/análise , Titânio/química , Animais , Antibacterianos/química , Aptâmeros de Nucleotídeos/química , DNA/química , Teoria da Densidade Funcional , Técnicas Eletroquímicas/métodos , Ouro/efeitos da radiação , Raios Infravermelhos , Masculino , Nanopartículas Metálicas/efeitos da radiação , Camundongos , Modelos Químicos , Nanotubos/efeitos da radiação , Óptica e Fotônica/métodos , Tetraciclina/química , Titânio/efeitos da radiação
15.
Anal Chem ; 91(22): 14657-14665, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31610644

RESUMO

The development of practical and sensitive tools for detecting phosphate deficiency could facilitate engineering approaches to enhance crop yield and quality in phosphate-stressed environments, reducing the misuse of nonrenewable fertilizers and their consequent ecological impact. Herein, a 975 nm-activated method based on ZrO2:Yb,Er@ZrO2 core@shell upconversion nanoparticles is presented for rapid visualization and determination of the phosphate ions in aqueous solutions and extracts. At optimized thickness, the nondoped ZrO2 shell not only enhances the emission of the ZrO2:Yb,Er but also provides an active surface for the intense interaction with the phosphate group, allowing a "label-free" determination that avoids the use of additional phosphate-recognizing elements like ligands or antibodies. According to the experimental evidence, the optical output of the ZrO2:Yb,Er@ZrO2 nanoparticles specifically matches with the absorption spectrum of the fast green alimentary dye (FG) electrostatically attached to the nanoparticle surface, activating the Förster resonance energy transfer (FRET) and thereby the upconversion luminescence quenching. Upon addition of the phosphate ions and the covalent interaction with the ZrO2:Yb,Er@ZrO2-FG nanocomplex, the FG is gradually removed, displaying a fast and reproducible "turn-on" luminescence which allows measurements in a few minutes. This rapid response is due to the stronger coordination between the ZrO2 shell and the phosphate compared to the FG molecules (-31.97 and -5.99 eV, respectively). The detection method was then effectively modulated in a 20-1000 nM linear response range without interfering effects of commonly coexisting ions, achieving a detection limit up to 15 times lower than that obtained with the conventionally used colorimetric methods.


Assuntos
Substâncias Luminescentes/química , Nanopartículas Metálicas/química , Fosfatos/análise , Corantes de Rosanilina/química , Érbio/química , Érbio/efeitos da radiação , Transferência Ressonante de Energia de Fluorescência/métodos , Raios Infravermelhos , Limite de Detecção , Luminescência , Substâncias Luminescentes/efeitos da radiação , Medições Luminescentes/métodos , Nanopartículas Metálicas/efeitos da radiação , Estudo de Prova de Conceito , Águas Residuárias/análise , Poluição Química da Água/análise , Itérbio/química , Itérbio/efeitos da radiação , Zircônio/química , Zircônio/efeitos da radiação
16.
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
17.
ACS Sens ; 4(10): 2724-2729, 2019 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-31564103

RESUMO

Trace concentration of formaldehyde can damage human health and environment. Consequently, it is of great significance to develop an ultrasensitive sensor for its determination. Herein, an ingenious and efficient photoelectrochemical sensor for formaldehyde was constructed by amorphous TiO2 hollow spheres incorporated with Ag+ ions, which were brought about by silica template etching and then the exchange of Ag+/Na+ ions. The amorphous TiO2 acted the dual role of Ag+ ion probe carriers and photoelectric materials. Upon exposure to the increased concentration of formaldehyde, the Ag nanoparticles were produced in situ, and photocurrent amplification was then achieved in a proportional manner. It is attributed to the injection of hot electrons from plasmonic Ag nanoparticles into the conduction band of amorphous titanium dioxide and therefore enhanced the photocurrent. The linear relationship between 1 and 400 pmol L-1 resulted from the enhanced photocurrent and increased concentration of formaldehyde, and the detection limit was 0.4 pmol L-1. Benefiting from an in situ and unique sensitization strategy, this photoelectrochemical sensor exhibited many advantages such as sensitivity, selectivity, cost-effectiveness, convenience of fabrication, low power consumption, and stability.


Assuntos
Técnicas Eletroquímicas/métodos , Formaldeído/análise , Nanopartículas Metálicas/química , Fotoquímica/métodos , Titânio/química , Técnicas Eletroquímicas/instrumentação , Eletrodos , Luz , Limite de Detecção , Nanopartículas Metálicas/efeitos da radiação , Prata/química , Prata/efeitos da radiação
18.
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
19.
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
20.
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
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