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1.
Chem Commun (Camb) ; 56(35): 4797-4800, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32227051

RESUMO

The measurement of exchangeable Cu2+ levels in biological samples is gaining interest in the context of copper-related pathologies. Here, we report a Tb3+ luminescent turn-off sensor for Cu2+ based on the specific and suitable-affinity Xxx-Zzz-His (ATCUN) peptide motif, enabling Cu2+ detection in the presence of a biological fluorescent background.


Assuntos
Cobre/análise , Peptídeos/química , Térbio/química , Animais , Cobre/química , Luminescência , Albumina Sérica/química , Suínos
2.
Food Chem ; 320: 126624, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32208181

RESUMO

A ratiometric fluorescence (FL) sensor was fabricated by coordinating 2, 6-pyridinedicarboxylic acid (DPA) sensitized Tb3+ (Tb-DPA) with NH2 and COOH on the surface of the N-doped carbon dots (N-CDs) for detecting Hg2+ in seafood. The sensor exhibited two FL emissions at 436 nm (N-CDs) as the response signal and at 543 nm (Tb-DPA) as the reference signal when excited at 290 nm. After adding Hg2+, the FL emission at 436 nm was significantly quenched and the FL emission at 543 nm was negligibly changed. The electron transfer (ET) between COO- of N-CDs and Hg2+ led to the FL quenching of N-CDs. The FL ratio (F436/F543) exhibited a good linear relationship in the Hg2+ concentrations of 1161.51 µM with a low limit of detection (LOD) of ~37 nM. The sensor presented high selectivity, satisfactory accuracy and precision toward Hg2+ in seafood with recoveries of 86.45-114.47% and RSDs of 0.20-1.92%.


Assuntos
Carbono/química , Análise de Alimentos , Mercúrio/análise , Alimentos Marinhos/análise , Térbio/química , Fluorescência , Limite de Detecção , Mercúrio/química , Pontos Quânticos , Espectrometria de Fluorescência
3.
Chem Commun (Camb) ; 56(21): 3183-3186, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32067022

RESUMO

A novel nanoarchitecture (MSN-Tb-UbR) was prepared by modifying rhodamine B-labelled Ubs (Ub-Rs) on the surface of mesoporous silica nanoparticles (MSNs) loaded with Tb3+-complexes. The MSN-Tb-UbR exhibits ratiometric sensing ability for DUB (UCH-L1) with good sensitivity and selectivity.


Assuntos
Nanopartículas/química , Dióxido de Silício/química , Ubiquitina Tiolesterase/análise , Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes/química , Porosidade , Rodaminas/química , Propriedades de Superfície , Térbio/química
4.
Ecotoxicol Environ Saf ; 188: 109921, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31711778

RESUMO

The presence of pesticides in water has emerged as a momentous environmental issue over the past decades. Herein, a terbium doped Ti/PbO2 (denoted as Ti/PbO2-Tb) dimensionally stable Ti/PbO2-Tb anode has been successfully prepared by one-step electrodeposition path for electrocatalytic degradation of imidacloprid (IMD) wastewater with high efficiency. Ti/PbO2-Tb electrode presents higher oxygen evolution potential, lower charge transfer resistance, stronger stability, longer service lifetime and outstanding electrocatalytic activity than Ti/PbO2 electrode. The optimum condition for IMD oxidation is obtained by analyzing the effects of some critical operating parameters including temperature, initial pH, current density and electrolyte concentration. It is proved that 70.05% of chemical oxygen demand and 76.07% of IMD are removed after 2.5 h of degradation under current density of 8 mA cm-2, pH 9, temperature 30 °C and 7.0 g L-1 NaCl electrolyte. In addition, the electrode displays commendable energy saving property as well as favorable reusability. The degradation mechanism of IMD is proposed by analyzing the intermediates identified by LC-MS. The present research provides a feasible strategy to degrade IMD wastewater by Ti/PbO2-Tb electrode.


Assuntos
Técnicas Eletroquímicas/métodos , Neonicotinoides/análise , Nitrocompostos/análise , Térbio/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Análise da Demanda Biológica de Oxigênio , Técnicas Eletroquímicas/instrumentação , Eletrodos , Chumbo/química , Oxirredução , Óxidos/química , Titânio/química
5.
Mikrochim Acta ; 187(1): 53, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31848726

RESUMO

A fluorometric method is described for the determination of thrombin. Polymer nanoparticles containing the luminol-terbium(III) complex (luminol-Tb) were prepared where luminol acts as the bridging ligand, and Tb(III) acts as the central metal ion. Thrombin possesses a large number of electrons donating groups that coordinate with luminol-Tb. Following coordination, the rigidity of the linker is increased, and this decreases the non-radiative decay rate and induces an increase in fluorescence intensity at 430 nm. Hence, thrombin can be fluorometrically determined. The detection limit of thrombin is as low as 3.5 pM (at an SNR of 3). This is about 10 times lower than assays using an aptamer. The method was applied in the determination of thrombin in human serum via the standard addition method and gave satisfying results. Graphical abstractSchematic representation of the preparation of the luminol-Tb(III) complex in a nanoparticle host by the self-assembly of luminol and Tb(III) ions. Thrombin readily coordinates with the luminol-Tb(III) system, and this results in particle aggregation. The blue fluorescence of luminol increases strongly, and this effect provides the basis for fluorometric determination of thrombin.


Assuntos
Complexos de Coordenação/química , Fluorescência , Nanopartículas/química , Polímeros/química , Térbio/química , Trombina/análise , Complexos de Coordenação/síntese química , Luminol/química , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
6.
Sci Adv ; 5(11): eaay6484, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31763458

RESUMO

Hydroxyapatite (HA) plays an important role in clinical bone repair. However, it remains a challenge to accurately determine its changes during bone reconstruction and to identify its differences from native bone apatite. Here, terbium (Tb) doped uniform HA nanocrystals were implanted into bone tissue and compared with native bone apatite. These comparisons demonstrated the occurrence of compositional and structural alteration of the implanted HA nanocrystals, and their gradual degradation, during bone reconstruction. They also revealed notable differences between HA nanocrystals and bone apatite crystals in crystal size, distribution pattern, and state of existence in bone tissue. Although synthetic HA nanocrystals could osteointegrate with bone tissue, they still seemed to be treated as foreign material in this tissue and thus were gradually degraded. These findings can help to identify and rethink the function of synthetic apatite and bone apatite, which will benefit future design and application of biomimetic bone repair materials.


Assuntos
Apatitas/química , Regeneração Óssea/fisiologia , Osso e Ossos/fisiopatologia , Durapatita/química , Nanopartículas/química , Térbio/química , Animais , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Regeneração Óssea/efeitos dos fármacos , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/cirurgia , Linhagem Celular Tumoral , Membro Posterior , Humanos , Microscopia Eletrônica de Transmissão , Nanopartículas/administração & dosagem , Nanopartículas/ultraestrutura , Coelhos , Cicatrização/efeitos dos fármacos , Cicatrização/fisiologia
7.
Analyst ; 144(19): 5875-5881, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31486467

RESUMO

A unique metal-organic framework with the formula [Cd4(H2L)2(L)·H2O]·3H2O (H4L = 5,5'-(1H-1,2,4-triazole-3,5-diyl)diisophthalic acid) was successfully constructed under solvothermal conditions. The frameworks with multiple free Lewis base sites and Lewis acid sites exhibited easily sensitized properties. After the encapsulation of Tb3+ cations, the as-synthesized Tb3+@Cd-MOF demonstrated strong luminescence induced by the efficient energy transfer from the bridging ligands to the Tb3+ cations, with the potential to serve as a chemical sensor. Interestingly, Tb3+@Cd-MOF was proven to be a very promising and highly selective and sensitive luminescent platform for the quantitative detection of arginine, which is the biomarker of cystinuria. The fluorescent probe presented high selectivity to arginine in urine with strong luminescence quenching. Furthermore, a convenient fluorescence-based test paper for the visual detection of arginine in applications was prepared. For the first time, arginine was quantified and monitored in urine by a highly efficient recyclable fluorescent sensor based on Tb3+-functionalized MOF hybrids, which may be a potential candidate for the further development of clinical diagnostic tools.


Assuntos
Arginina/urina , Corantes Fluorescentes/química , Estruturas Metalorgânicas/química , Térbio/química , Biomarcadores/urina , Cistinúria/diagnóstico , Fluorescência , Corantes Fluorescentes/síntese química , Humanos , Limite de Detecção , Estruturas Metalorgânicas/síntese química , Espectrometria de Fluorescência/métodos
8.
Mater Sci Eng C Mater Biol Appl ; 104: 109976, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31499989

RESUMO

The preparation of fluorescent inorganic-organic polymer composites for biomedical applications has become one of the most interest research focuses recently. In this work, we reported a novel method for the preparation of Tb3+-doped luminescent layered double hydroxides (LDHs) based composites by taken advantage of a one-pot supramolecular chemistry. The adamantane can be immobilized on the surface of Tb3+-doped LDHs to obtain LDH-Ad, which could be further utilized for modified by the ß-cyclodextrin (ß-CD) containing hyperbranched polyglycerols (ß-CD-HPG) through the host-guest interaction. Based on the characterization results, we demonstrated that the hyperbranched polyglycerol could be facilely introduced on these fluorescent Tb3+-doped LDHs through the method described in this work. The obtained Tb3+-doped LDHs based polymer composites (LDHs-ß-CD-HPG) display improved water dispersibility and still maintain their fluorescence. The results based on various biological assays suggest that LDHs-ß-CD-HPG polymer composites are of low cytotoxicity and their cell uptake behavior can be effectively traced using confocal laser imaging. All of the above results demonstrated that the fluorescent Tb3+-doped LDHs based polymer composites could be effectively surface modified with hydrophilic hyperbranched polymers through a one-pot facile host-guest interaction and the resultant fluorescent composites are of excellent physicochemical properties and display great potential for biomedical applications. This novel surface modification method should also be important for fabrication of other multifunctional composites and therefore great advanced the development of biomedical applications of fluorescent LDHs based polymer composites and related materials.


Assuntos
Glicerol/química , Hidróxidos/química , Polímeros/química , Térbio/química , Celulose/química , Corantes/química , Ciclodextrinas/química , Fluorescência , Interações Hidrofóbicas e Hidrofílicas , Luminescência , Polimerização , Água/química , beta-Ciclodextrinas/química
9.
Analyst ; 144(20): 5971-5979, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31498361

RESUMO

Alkaline phosphatase (ALP) is an important enzyme related to many clinical diseases and also widely used as a labeling enzyme for immunoassay. Herein, a new electrochemical sensing strategy for ALP activity was proposed, which was based on the ALP-triggered methylene blue (MB) release from a lanthanide coordination polymer and successive penetration through a self-assembled dodecanethiol monolayer for electrochemical response. The supramolecular lanthanide coordination polymer was constructed by using guanine monophosphate (GMP) and Tb3+ as the ligand and the metal ion, respectively, and the encapsulated MB as the signal molecule. ALP catalyzed the cleavage of the phosphate group from the GMP ligand and disrupted the coordination polymer network to release abundant MB molecules for electrochemical responses related to ALP activity. The obtained lanthanide coordination polymers were well characterized by various techniques. The fabricated electrochemical sensor for ALP activity assay shows distinct advantages such as being one-step, label-free, immobilization-free and highly sensitive. The detection limit toward ALP activity was down to 0.5 U L-1. With the aid of a MB enrichment process on the modified electrode before measurement, the detection limit could be further improved to 0.1 U L-1. Moreover, the assay method could be applied for ALP detection in complex matrixes such as human serum and also for efficient inhibitor evaluation. Thus, the current study provides a new pathway to the fabrication of a coordination polymer-based electrochemical sensing platform for applications in disease diagnosis and drug discovery.


Assuntos
Fosfatase Alcalina/análise , Bioensaio , Azul de Metileno/química , Polímeros/química , Térbio/química , Alcanos/química , Bioensaio/métodos , Catálise , Técnicas Eletroquímicas/métodos , Sensibilidade e Especificidade
10.
Biosens Bioelectron ; 142: 111536, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31362204

RESUMO

Combining different metal-organic frameworks (MOFs) into a conjugate material can integrate the properties of each MOF component and further lead to emergent properties from the synergistic heterostructured units. In this work, two kinds of bimetallic TbFe-MOFs have been designed by MOF-on-MOF strategy and utilized as a platform for anchoring carbohydrate antigen 125 (CA125) aptamer to detect CA125 and living michigan cancer foundation-7 (MCF-7) cells. Although the integrated MOF-on-MOF architectures show similar chemical and structural features to that of the top layer, the Fe-MOF-on-Tb-MOF and Tb-MOF-on-Fe-MOF have different surface nanostructures to their parent MOFs. The developed aptasensor based on Tb-MOF-on-Fe-MOF displays higher stability of the formed G-quadruplex between aptamer and CA125 than that based on Fe-MOF-on-Tb-MOF, owing to stronger immobilization behavior of the aptamer for the Tb-MOF-on-Fe-MOF composite. The developed aptasensor provides an extremely low detection limit of 58 µU·mL-1 towards CA125 within a wide linear range from 100 µU·mL-1 to 200 U·mL-1, which is significantly lower than those of all reported sensors. This aptasensor also has high selectivity, good stability, acceptable reproducibility, and excellent applicability in human serum. Moreover, the Tb-MOF-on-Fe-MOF nanoarchitecture demonstrates superior biocompatibility and good endocytosis. As a result, the developed aptasensor illustrates high sensitivity for detection of MCF-7 cells with an extremely low detection limit of 19 cell·mL-1. Therefore, the proposed aptasensor based on Tb-MOF-on-Fe-MOF exhibits great potentials for early diagnosis of tumors.


Assuntos
Aptâmeros de Nucleotídeos/química , Antígeno Ca-125/análise , Ferro/química , Estruturas Metalorgânicas/química , RNA/química , Térbio/química , Técnicas Biossensoriais/métodos , Humanos , Limite de Detecção , Células MCF-7 , Neoplasias/patologia
11.
Int J Mol Sci ; 20(13)2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31252567

RESUMO

The low photostability of conventional organic dyes and the toxicity of cadmium-based luminescent quantum dots have prompted the development of novel probes for in vitro and in vivo labelling. Here, a new fluorescent lanthanide probe based on silica nanoparticles is fabricated and investigated for optically traceable in vitro translocator protein (TSPO) targeting. The targeting and detection of TSPO receptor, overexpressed in several pathological states, including neurodegenerative diseases and cancers, may provide valuable information for the early diagnosis and therapy of human disorders. Green fluorescent terbium(III)-calix[4]arene derivative complexes are encapsulated within silica nanoparticles and surface functionalized amine groups are conjugated with selective TSPO ligands based on a 2-phenylimidazo[1,2-a]pyridine acetamide structure containing derivatizable carboxylic groups. The photophysical properties of the terbium complex, promising for biological labelling, are demonstrated to be successfully conveyed to the realized nanoarchitectures. In addition, the high degree of biocompatibility, assessed by cell viability assay and the selectivity towards TSPO mitochondrial membrane receptors, proven by subcellular fractional studies, highlight targeting potential of this nanostructure for in vitro labelling of mitochondria.


Assuntos
Corantes Fluorescentes/química , Nanopartículas/química , Dióxido de Silício/química , Térbio/química , Calixarenos/química , Linhagem Celular Tumoral , Corantes Fluorescentes/farmacologia , Humanos , Ligantes , Fenóis/química , Ligação Proteica , Receptores de GABA/efeitos dos fármacos , Receptores de GABA/metabolismo
12.
Mikrochim Acta ; 186(6): 389, 2019 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-31152239

RESUMO

The authors report on an energy transfer based fluorometric approach for the detection of nitroaromatic pollutants. This is achieved using 4-mercaptobenzoic acid (4-MBA)-capped CaF2:Tb3+ nanocrystals that were synthesized by a microwave procedure. 4-MBA acts as both a capping agent and a sensitizer for the Tb3+ ions in CaF2 host matrix. This approach is different from the earlier studies where Ce3+ is generally used as the sensitizer for the Ln3+ ions. The use of capping ligand as sensitizer has the feature that binding of nitroaromatics directly to the sensitizer can alter the energy transfer efficiency between the sensitizer and the Tb3+ ions. The fluorescent nanocrystal probe doped with 2% of Tb3+ displays green emission with a peak at 542 nm if photoexcited at 311 nm. The emission is quenched if the nanocrystals are exposed to nitroaromatic compounds such as 4-nitrophenol, 2,4-dinitrophenol, 2,4,6-trinitrophenol (picric acid), 4-nitrotoluene, 2,4-dinitrotoluene and 2,4,6-trinitrotoluene. These analytes also cause a (longwave/shortwave) shift in the excitation maxima which helps in identifying the individual nitroaromatic compound using single nanoprobe. The respective detection limits (by applying the 3σ/K criterion) are 0.86 µM, 0.83 µM, 0.78 µM, 0.36 µM, 1.5 µM, and 1.96 µM. Graphical abstract Schematic illustration of the use of 4-mercaptobenzoic acid (MBA)-capped CaF2:Tb3+ nanocrystals as a fluorescent nanoprobe for the detection of nitroaromatic analytes. The Tb3+ ions show strong green fluorescence via 4-MBA-induced ligand sensitization. The specific π interaction between 4-MBA capped CaF2 nanocrystals and nitroaromatics leads to reduction in the fluorescence intensity by inhibiting the energy transfer from 4-MBA to Tb3+ ion in CaF2 nanocrystals.


Assuntos
Corantes Fluorescentes/química , Nanopartículas Metálicas/química , Nitrobenzenos/análise , Nitrofenóis/análise , Poluentes Químicos da Água/análise , Benzoatos/química , Fluoreto de Cálcio/química , Corantes Fluorescentes/síntese química , Índia , Lagos/análise , Limite de Detecção , Rios/química , Espectrometria de Fluorescência/métodos , Compostos de Sulfidrila/química , Térbio/química
13.
Dalton Trans ; 48(25): 9291-9302, 2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-31166338

RESUMO

The study aims to understand the significance of collective rare earth (RE3+) substitutions in ZrO2 structures for biomedical applications. The RE3+ ions namely Yb3+, Dy3+, Tb3+, Gd3+, Eu3+, and Nd3+ were selected and their concentrations were adjusted to obtain three different combinations. The influence of RE3+ on the crystal structure of ZrO2 alongside the absorption, luminescence, mechanical, magnetic, computed tomography (CT), magnetic resonance imaging (MRI) properties was explored. The concomitant effect of the average ionic size and RE3+ concentration determines the crystallization behavior of ZrO2 at elevated temperatures. The collective RE3+ substitutions exhibit both up-conversion and down-conversion emissions with their respective excitation at 793 and 350 nm. Nevertheless, increment in the concentration of RE3+ is found to be detrimental to the mechanical stability of ZrO2. The collective characteristics of multiple RE3+ demonstrate the potential of the investigated system in multimodal imaging applications. The unique luminescence characteristics of Eu3+ and Tb3+ are promising for fluorescence imaging while the presence of Dy3+, Tb3+, Gd3+ and Nd3+ unveils a paramagnetic response required for MRI. In addition, Dy3+ and Yb3+ contribute to the high X-ray absorption coefficient values suitable for X-ray CT imaging.


Assuntos
Materiais Biocompatíveis/química , Metais Terras Raras/química , Zircônio/química , Disprósio/química , Európio/química , Gadolínio/química , Luminescência , Imagem por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Fenômenos Mecânicos , Neodímio/química , Térbio/química , Tomografia Computadorizada por Raios X , Itérbio/química
14.
Mater Sci Eng C Mater Biol Appl ; 102: 578-588, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147030

RESUMO

An adsorbent-heater-thermometer nanomaterial, (ZIF-8,EuxTby)@AuNP, based on ZIF-8 (adsorbent), containing Eu3+ and/or Tb3+ ions (thermometer) and gold nanoparticles (AuNPs, heater) was designed, synthetized, characterized, and applied to controlled drug release. These composite materials were characterized as core-shell nanocrystals with the AuNPs being the core, around which the crystalline ZIF-8 has grown (shell) and onto which the lanthanide ions have been incorporated or chemosorbed. This shell of ZIF-8 acts as adsorbent of the drugs, the AuNPs act as heaters, while the luminescence intensities of the ligand and the lanthanide ions are used for temperature monitoring. This thermo-responsive material can be activated by visible irradiation to release small molecules in a controlled manner as established for the model pharmaceutical compounds 5-fluorouracil and caffeine. Computer simulations and transition state theory calculations shown that the diffusion of small molecules between neighboring pores in ZIF-8 is severely restricted and involves high-energy barriers. These findings imply that these molecules are uploaded onto and released from the ZIF-8 surface instead of being inside the cavities. This is the first report of ZIF-8 nanocrystals (adsorbents) containing simultaneously lanthanide ions as sensitive nanothermometers and AuNPs as heaters for controlled drug release in a physiological temperature range. These results provide a proof-of-concept that can be applied to other classes of materials, and offer a novel perspective on the design of self-assembly multifunctional thermo-responsive adsorbing materials that are easily prepared and promptly controllable.


Assuntos
Preparações de Ação Retardada/farmacologia , Liberação Controlada de Fármacos , Ouro/química , Nanopartículas Metálicas/química , Nanoestruturas/química , Termômetros , Zeolitas/química , Adsorção , Cafeína/farmacologia , Morte Celular/efeitos dos fármacos , Difusão , Érbio/química , Fluoruracila/farmacologia , Luminescência , Temperatura , Térbio/química , Fatores de Tempo
15.
Mater Sci Eng C Mater Biol Appl ; 102: 810-819, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147053

RESUMO

The significance of Tb3+ inclusions at the zirconia toughened alumina (ZTA) structure was explored. The influence of Tb3+ content at the crystal structures of ZrO2 and Al2O3 and the resultant optical, mechanical, magnetic and cytotoxicity properties were deliberated. The critical role of Tb3+ to attain a structurally stable ZTA until 1500 °C is ensured. Depending on the Tb3+ content, either tetragonal zirconia (t-ZrO2) or cubic zirconia (c-ZrO2) structures were stabilized while the propensity of Tb3+ reaction with Al2O3 to yield TbAlO3 is transpired only after exceeding the occupancy limit in ZrO2. The green emission and paramagnetic features are imparted by the Tb3+ inclusions at the ZTA structure. Dense and pore free microstructures with a direct impact on the improved mechanical features of ZTA is empowered by the presence of Tb3+. Further, the results from MTT assay and live/dead cell staining ensured the negligence of Tb3+ contained ZTA systems to induce toxicity.


Assuntos
Óxido de Alumínio/química , Luminescência , Térbio/química , Zircônio/química , Linhagem Celular Tumoral , Humanos , Fenômenos Magnéticos , Análise Espectral Raman , Propriedades de Superfície , Temperatura , Difração de Raios X
16.
Anal Bioanal Chem ; 411(17): 3979-3988, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31089787

RESUMO

Herein, a universal and multifunctional fluorescence sensor platform is designed by the interaction of aggregation/dispersion gold nanoparticles (AuNPs) with Tb-metal-organic frameworks (Tb-MOFs). It is found that the dispersed AuNPs rather than the aggregated ones can quench effectively the fluorescence of Tb-MOFs, and the quenching process presumably involves the mechanism of inner filter effect (IFE), dynamic quenching effect (DQE), and fluorescence resonance energy transfer (FRET). The different affinities of aptamer and aptamer-target complex toward AuNPs are employed to modulate the fluorescence signal change of Tb-MOFs. As the proof of concept, prostate-specific antigen (PSA), an efficient tumor indicator for prostate cancer, is selected as the target. At first, the PSA aptamer can protect AuNPs against salt-induced aggregation, leading to the fluorescence of Tb-MOFs quenching. Subsequently, upon PSA introduction, the rigid aptamer-PSA complex is formed and cannot stabilize AuNPs in high salt conditions, so the AuNPs aggregate significantly and the fluorescence of Tb-MOFs is restored. The linear range of PSA is achieved from 1 to 100 ng/mL with a detection limit of 0.36 ng/mL. Finally, this method has been validated to be sensitive and specific for PSA in human urine samples. Graphical abstract.


Assuntos
Técnicas Biossensoriais , Ouro/química , Imunoensaio/métodos , Nanopartículas Metálicas/química , Estruturas Metalorgânicas/química , Antígeno Prostático Específico/análise , Térbio/química , Fluorescência , Humanos , Limite de Detecção , Masculino , Microscopia Eletrônica de Transmissão , Antígeno Prostático Específico/urina , Espectroscopia de Infravermelho com Transformada de Fourier , Ressonância de Plasmônio de Superfície
17.
Analyst ; 144(12): 3843-3852, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31098604

RESUMO

Acute leukemia is a malignant clonal disease of hematopoietic stem cells with a high prevalence and mortality rate. However, there are no efficient tools to facilitate early diagnosis and treatment of leukemia. Therefore, development of new methods for the early diagnosis and prevention of leukemia, especially non-invasive diagnosis at the cellular level, is imperative. Here, a label-free signal-on fluorescence aptasensor based on terbium(iii)-aptamer (Tb3+-apt) was applied for the detection of leukemia. The aptamer sensitizes the fluorescence of Tb3+ and forms the strong fluorescent Tb3+-apt probe. The target cells, the T-cell acute lymphoblastic leukemia cell line (CCRF-CEM) combined with the Tb3+-apt probe to form the Tb3+-apt-CEM complex, were removed by centrifugation, and the supernatant containing a small amount of the Tb3+-apt probe was detected using a fluorescence spectrophotometer. The logarithm of cell concentration showed a good linear relationship (R2 = 0.9881) with the fluorescence signal. The linear range for CCRF-CEM detection was 5-5 × 106 cells per ml, while the detection limit was 5 cells per ml of the binding buffer. Clinical samples were collected from 100 cases, and the specificity and positive rates detected by this method were up to 94% and 90%, respectively. Therefore, a single-stranded DNA-sensitized terbium(iii) luminescence method diagnostic was developed which is rapid, sensitive, and economical and can be used for diagnosis of various types of leukemia at the early stage.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/diagnóstico , Térbio/química , Adolescente , Adulto , Aptâmeros de Nucleotídeos/toxicidade , Sequência de Bases , Linhagem Celular Tumoral , Criança , Pré-Escolar , Feminino , Fluorescência , Humanos , Limite de Detecção , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células T Precursoras/sangue , Espectrometria de Fluorescência/métodos , Térbio/toxicidade , Adulto Jovem
18.
J Nanobiotechnology ; 17(1): 54, 2019 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-30992018

RESUMO

BACKGROUND: Nanomaterials that exhibit intrinsic enzyme-like characteristics have shown great promise as potential antibacterial agents. However, many of them exhibit inefficient antibacterial activity and biosafety problems that limit their usefulness. The development of new nanomaterials with good biocompatibility and rapid bactericidal effects is therefore highly desirable. Here, we show a new type of terbium oxide nanoparticles (Tb4O7 NPs) with intrinsic oxidase-like activity for in vitro and in vivo antibacterial application. RESULTS: We find that Tb4O7 NPs can quickly oxidize a series of organic substrates in the absence of hydrogen peroxide. The oxidase-like capacity of Tb4O7 NPs allows these NPs to consume antioxidant biomolecules and generate reactive oxygen species to disable bacteria in vitro. Moreover, the in vivo experiments showed that Tb4O7 NPs are efficacious in wound-healing and are protective of normal tissues. CONCLUSIONS: Our results reveal that Tb4O7 NPs have intrinsic oxidase-like activity and show effective antibacterial ability both in vitro and in vivo. These findings demonstrate that Tb4O7 NPs are effective antibacterial agents and may have a potential application in wound healing.


Assuntos
Antibacterianos/química , Escherichia coli , Nanopartículas Metálicas/química , Óxidos/química , Oxirredutases/química , Staphylococcus aureus , Térbio/química , Cicatrização , Animais , Antibacterianos/farmacologia , Materiais Biocompatíveis/química , Sobrevivência Celular , Escherichia coli/efeitos dos fármacos , Hemólise , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos Endogâmicos BALB C , Óxidos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Térbio/farmacologia
19.
Luminescence ; 34(4): 432-436, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31012253

RESUMO

In the Ba9 Lu2 Si6 O24 (BLS) host, Ce3+ shows cyan emissions peaking at 490 nm under 400 nm excitations. BLS:Tb3+ only can be effectively excited by 254 nm light and gives rise to green emissions at 553 nm. However, both the cyan and green emissions can be obtained in BLS:Ce3+ ,Tb3+ under 400 nm excitations due to effective energy transfers from Ce3+ to Tb3+ . BLS:Mn2+ shows red emissions peaking at 610 nm under 414 nm excitations. By co-doping Ce3+ , Tb3+ and Mn2+ , tunable full-color emissions were obtained. The BLS:0.3Ce3+ ,0.6Tb3+ ,0.15Mn2+ single phosphor exhibits a white light with a high color rendering index of 85 and a correlated color temperature of 5480 K under 400 nm excitation.


Assuntos
Luz , Bário/química , Cério/química , Transferência de Energia , Medições Luminescentes , Lutécio/química , Magnésio/química , Oxigênio/química , Silício/química , Temperatura , Térbio/química
20.
Biosens Bioelectron ; 135: 208-215, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31026775

RESUMO

A Eu-metal organic framework (Eu-MOF) probe with dual-emission was reported for the ratiometric fluorescence detection of H2O2 and glucose. Because of the special nucleophilic reaction between boric group and H2O2, Eu3+ and 5-boronobenzene-1,3-dicarboxylic acid (BBDC) were selected to synthesize the functional MOF probe via a simple one-pot solvothermal method. The Eu-MOF shows dual-emission at 370 and 623 nm with the single excitation at 270 nm due to the energy transfer efficiency change for antenna effect procedure. After addition of H2O2, the red emission of Eu-MOF weakened and the blue emission enhances immediately under 270 nm irradiation, so the ratiometric fluorescence detection is established. Moreover, the obvious color change for visual measuring of H2O2 and glucose is illustrated to reveal the merit of Eu-MOF probe. The proposed method was demonstrated to be highly sensitive and selective for H2O2 and glucose, with the low detection limits of 0.0335 and 0.0643 µM, respectively. The established boric-acid-functional Eu-MOF sensing platform was proved as the powerful probe for H2O2 and the metabolites involved in H2O2-generating reaction.


Assuntos
Ácidos Bóricos/química , Európio/química , Glicosúria/urina , Peróxido de Hidrogênio/análise , Estruturas Metalorgânicas/química , Animais , Técnicas Biossensoriais/métodos , Corantes Fluorescentes/química , Glucose/análise , Limite de Detecção , Camundongos , Chuva/química , Espectrometria de Fluorescência/métodos , Térbio/química
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