Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Chem Commun (Camb) ; 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32195487

RESUMO

Propanedioyl dihydrazide (PDH), traditionally believed to be non-fluorescent, was first discovered to emit substantial fluorescence in both the solid state and solvents. Then, significantly, a novel strategy is provided: fluorescent non-aromatic small molecules with rigid molecular structures could be constructed by forming hydrogen bonds.

2.
Chem Commun (Camb) ; 56(8): 1191-1194, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31897453

RESUMO

Currently, fluorescent sensors for the detection of H2O in D2O are still quite rare. Herein, we present a dual-site controlled fluorescent sensor (CF-D2O) for the detection of H2O in D2O. As the H2O content in D2O decreases (namely, the purity of D2O increases), sensor CF-D2O provides two turn-on fluorescence signals. The response mechanism of sensor CF-D2O to H2O is based on the deprotonation of the two hydroxyl groups, as well as the FRET process between coumarin and xanthene units.

3.
Anal Chem ; 91(24): 15591-15598, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31726828

RESUMO

Emergence of fluorescence imaging with real-time and in situ manners has revolutionized the fields of tracing and defining enzymes in biological systems. ß-galactosidase is a kind of enzyme that plays vital roles in controlling multitudes of cellular functions and participating in disease pathogenesis. Thus, building fluorescent probes with high sensitivity and fidelity for visualizing ß-galactosidase in biological systems is very significative. Herein, we engineered the first ultrsensitivity ratiometric fluorescent probe CG based on ICT-FRET synergetic mechanisms for detecting ß-galactosidase. The spectrum data show that probe CG has a fast response (<20 s), as well as a very low detection limit to ß-galactosidase (0.081 U/mL). Moreover, by calculation of a serious of kinetic parameters including Km (1.42 µM), kcat (7.04 s-1), and kcat/Km (4.96 µM-1 s-1), CG demonstrates high affinity and high catalytic efficiency to ß-galactosidase. Because of its excellent water solubility, CG has well biocompatibility to visualize the ß-galactosidase in living cells. Furthermore, for imaging in bioapplications, CG is capable of detecting ß-galactosidase not only in overexpressed cell lines but also in transient expressed cell lines. Significantly, CG can monitor ß-galactosidase ex vivo selectively. We hope ongoing work to employ CG can be as an ultrasensitive powerful tool for further seeking the physiological and pathological functions in biological organisms.

4.
Chem Commun (Camb) ; 55(70): 10440-10443, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31410422

RESUMO

In this work, a unique dual-site controlled fluorescent probe was presented for the sensitive and concurrent detection of pH in the cytoplasm and lysosomes. With the probe, the simultaneous down-regulation of pH in the lysosomes and cytoplasm during autophagy has been successfully revealed for the first time.


Assuntos
Autofagia , Citoplasma/metabolismo , Regulação para Baixo , Concentração de Íons de Hidrogênio , Lisossomos/metabolismo , Sondas Moleculares/química , Sobrevivência Celular , Células Hep G2 , Humanos , Espectrometria de Fluorescência
5.
Chem Commun (Camb) ; 55(72): 10776-10779, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31432809

RESUMO

Herein, we present a dual-site ratiometric fluorescent probe based on the ICT-PET-FRET mechanism for the detection of pH in the ER. The probe showed a highly sensitive response to pH in the range of 5.0-7.2, and could be applied for the quantitative measurement of the pH values in the ER during ER stress and dexamethanose-induced stimulation.


Assuntos
Retículo Endoplasmático/metabolismo , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes/química , Dexametasona/farmacologia , Transporte de Elétrons , Retículo Endoplasmático/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio
6.
Anal Chem ; 91(17): 11397-11402, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31402659

RESUMO

Hydroxylamine (HA) is an important product of cell metabolism and plays a significant role in many biological processes, and therefore, real-time imaging of HA is of great importance for the in-depth study of its physiological and pathological functions. However, a HA-specific fluorescent probe is currently lacking primarily because the highly selective HA-responsive site is undeveloped. To address this critical issue, we present a HA-specific FRET-based fluorescent probe (RhChr) for the selective detection of HA in living systems. Inspired by aza-Michael addition, the unsaturated system appended with an iminium ion was employed as the new HA-specific response site. In response to HA, RhChr provided a ratiometric signal output with excellent selectivity toward HA over biothiols and ammonia. We have demonstrated that RhChr could be applied for the ratiometric imaging of endogenous HA in living cells and the evaluation of xanthine oxidase (XOD) activity in living organs.

7.
ACS Appl Mater Interfaces ; 11(33): 30218-30227, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31356040

RESUMO

4-Nitrotoluene (NT) is an important intermediate for the manufacture of dyes, agricultural chemicals, medicaments, and synthetic fibers. But its wide use has resulted in a series of ecological problems and health issues due to high toxicity, mutagenicity, and carcinogenicity. However, no fluorescent probes with high selectivity and high sensitivity to NT has been reported yet, and the current probes usually prefer to detect multi-nitrosubstituted nitroaromatic compounds (NACs) including 2,4,6-trinitrotoluene and 2,4,6-trinitrophenol. Herein, we report a series of pyrene-functionalized polysiloxanes with high selectivity and high sensitivity to NT. Pyrene was introduced into polysiloxane through a carbon-carbon double bond, and the formed rigid side-chain fluorophore and flexible backbone structure of polysiloxane provide an ideal platform for the highly selective detection of NT. We further explored the possible response mechanism and speculated that the high selectivity and high sensitivity were derived from the synergistic effect between steric hindrance and dipolar interaction. In addition, paper sensors based on the obtained fluorescent materials were fabricated and change in their high sensitivity and visible fluorescence indicated that the paper sensor is a simple testing tool for portable and visual detection of NT. Furthermore, the design strategy in this work provides a novel synthetic route to synthesize other fluorescent probes with unique selectivity to NACs detection.

8.
Anal Chem ; 91(15): 10056-10063, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31304737

RESUMO

Fluorescent probes for monitoring cell apoptosis are powerful tools in biological and pathological research. However, ratiometric probes for in situ and real-time visualization of apoptosis with high accuracy are still deficient, which limits the studies relative to cell apoptosis. In this work, a pH-sensitive and positively charged RNA binder was designed and synthesized for the first time for the ratiometric visualization of cell apoptosis. In healthy cells, the probe targets mitochondria with basic matrixes and high membrane potential and displays intense emission in the blue and red channels. During apoptosis, the probe is released from mitochondria, binds to basophilic RNA, and shows emission in only the red channel. Consequently, cell apoptosis caused by drug treatment could be efficiently and clearly monitored in a ratiometric manner. The probe is expected to facilitate the study of cell apoptosis and relative areas.

9.
Analyst ; 144(14): 4371-4379, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31197299

RESUMO

SO2 has been recently identified as an essential gas messenger followed by NO, CO and H2S. However, abnormal concentrations of SO2 in our bodies can cause many diseases. Thus, the real-time monitoring of SO2 to well define the generation, physiological and pathological functions of SO2 is urgently needed. In this work, we developed a novel SO2 fluorescent probe on the basis of the conjugation of semi-cyanine and coumarin derivate dyes with superior features, such as near-infrared (NIR) and two-photon dual-mode monitoring, a large Stokes shift (175 nm), ultrafast response towards SO2 (within 10 s), high selectivity and photostability. Furthermore, this probe could sense SO2 by dual colorimetric and fluorescence means. In biological imaging, the probe was able to trace exogenous and endogenous SO2 in living cells, mitochondria, E. coli, zebrafish and mice under an NIR and two-photon dual-mode. These results demonstrated that the probe has strong potential for studying the physiological and pathological functions of SO2in vitro and in vivo.


Assuntos
Cumarínicos/química , Corantes Fluorescentes/química , Indóis/química , Dióxido de Enxofre/análise , Animais , Colorimetria/métodos , Cumarínicos/síntese química , Cumarínicos/efeitos da radiação , Cumarínicos/toxicidade , Escherichia coli , Feminino , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/efeitos da radiação , Corantes Fluorescentes/toxicidade , Células Hep G2 , Humanos , Indóis/síntese química , Indóis/efeitos da radiação , Indóis/toxicidade , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência/métodos , Imagem Óptica/métodos , Fótons , Peixe-Zebra
10.
Anal Chem ; 91(9): 5513-5516, 2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31014068

RESUMO

Cysteine (Cys) is an important mediator to regulate the redox state of endoplasmic reticulum (ER), and its level is closely related with many ER stress induced serious diseases. Herein, we present an ER-specific fluorescent probe for the ratiometric imaging of cellular Cys for the first time. The probe exhibited desirable selectivity and sensitivity to Cys. Biological imaging experiments demonstrated that the probe possessed an ER-targeting property, showed ratiometric response to Cys in ER, and could be applied for the ratiometric imaging of Cys level changes during H2O2-induced redox imbalance in living cells.

11.
Anal Chem ; 91(3): 1719-1723, 2019 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-30645092

RESUMO

PDMS is biocompatible, economically viable, transparent, and facile to handle and thus is suitable for fluorescent microscopy and biological research. However, there has been no report about polysiloxane-based fluorescent probes applied in bioimaging. In this report, a two-photon polysiloxane-based reversible luminescent probe (P1) was fabricated for the first time. P1 is a powerful tool for detecting the ClO-/GSH cycle in situ both in live cells and in zebrafish. This work demonstrates the potential of polysiloxane-based fluorescent probes for versatile in vivo or in vitro applications in the future.

12.
Spectrochim Acta A Mol Biomol Spectrosc ; 209: 196-201, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30390505

RESUMO

Sulfur dioxide (SO2), as the fourth gas signal molecule, is closely related to many diseases including respiratory diseases, nervous system diseases, cardiovascular diseases and cancers. Herein, we present a novel mitochondria-targeted ratiometric fluorescent probe (CS) for the detection of SO2 in living cells and zebrafishes. The probe CS was constructed on the base of coumarin and benzopyranium fluorophores, and exhibited intense blue and red fluorescence simultaneously. After the response to SO2, the fluorescence at 433 nm enhanced significantly while the fluorescence at 683 nm decreased obviously. The probe CS has a high sensitivity and selectivity to SO2. Moreover, the probe CS has been successfully applied to the detection of mitochondrial SO2 in living cells and zebrafishes.


Assuntos
Fluorescência , Corantes Fluorescentes/química , Mitocôndrias/metabolismo , Imagem Molecular/métodos , Dióxido de Enxofre/análise , Peixe-Zebra/metabolismo , Animais , Cumarínicos/química , Células HeLa , Humanos
13.
Angew Chem Int Ed Engl ; 57(50): 16506-16510, 2018 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-30371018

RESUMO

Mitochondria and nucleus play crucial roles during cell apoptosis process. In this work, a unique fluorescent probe capable of reversible migration between mitochondria and nucleus, as well as detection of cell viability in a dual-color mode is presented. The dual-color probe targets mitochondria in healthy cells, to form aggregates with deep-red emission. It migrates into nucleus and binds to DNA to form monomers with green fluorescence during apoptosis. Interestingly, the migration is reversible dependent on cell viability, which enables the dynamic visualization of apoptosis process. With the probe, mitochondria and nucleus can be visualized in dual colors during apoptosis, and the cell viability could be monitored by the emission color and localization of the probe.


Assuntos
Núcleo Celular/ultraestrutura , Sobrevivência Celular , Corantes Fluorescentes/química , Microscopia de Fluorescência/métodos , Mitocôndrias/ultraestrutura , Apoptose , Dimerização , Fluorescência , Células HeLa , Humanos , Permeabilidade
14.
Luminescence ; 33(7): 1275-1280, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30256510

RESUMO

Abnormal lysosomal pH is closely associated with many diseases, and real-time monitoring of lysosomal pH is important for understanding the lysosome physiological nature. Here, we present a novel lysosome-targeting two-photon fluorescent probe (MP-lys) for monitoring pH changes in living cells. As a dual site-controlled probe, MP-lys employed morpholine and piperazine groups as the lysosome-targeting groups and pH response sites. MP-lys showed rapid, reversible and sensitive fluorescence response to pH. MP-lys possessed lysosome-targeting properties, and could be used for two-photon imaging of chloroquine-induced pH variation in living cells.


Assuntos
Corantes Fluorescentes/química , Lisossomos/química , Cloroquina/química , Fluorescência , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Morfolinas/química , Fótons , Piperazina/química
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 205: 528-533, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30077141

RESUMO

1,4-Dithiothreitol (DTT) is an important small-molecular reducing agent and has extensive applications in biochemistry, peptide/protein chemistry and clinical medicine. The development of effective methods for monitoring DTT is of great importance for its safe use and studying its toxicity to human. In this work, we present a two-photon red-emissive probe for the imaging of DTT in living cells, tissues and animals. The probe employed a two-photon red-emissive xanthene dye as the fluorophore and selected 2,4-dinitrophenylate as the novel recognition site for DTT. In response to DTT, the probe displayed excellent sensitivity and selectivity. The probe was successfully applied to the two-photon imaging of DTT in living cells, and the imaging of DTT in living tissues and animals.


Assuntos
Ditiotreitol/análise , Corantes Fluorescentes/química , Imagem Óptica/métodos , Animais , Ditiotreitol/química , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal , Xantenos/química
16.
Luminescence ; 33(6): 1048-1053, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29927540

RESUMO

1,4-Dithiothreitol (DTT) has wide applications in cell biology and biochemistry. Development of effective methods for monitoring DTT in biological systems is important for the safe handling and study of toxicity to humans. Herein, we describe a two-photon fluorescence probe (Rh-DTT) to detect DTT in living systems for the first time. Rh-DTT showed high selectivity and sensitivity to DTT. Rh-DTT can be successfully used for the two-photon imaging of DTT in living cells, and also can detect DTT in living tissues and mice.


Assuntos
Ditiotreitol/análise , Corantes Fluorescentes/química , Fótons , Xantenos/química , Animais , Sobrevivência Celular , Feminino , Corantes Fluorescentes/síntese química , Humanos , Fígado/química , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Células Tumorais Cultivadas
17.
J Fluoresc ; 28(2): 681-687, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29696451

RESUMO

Hydrogen peroxide (H2O2) plays important roles in the regulation of many biological processes, and the abnormal level of H2O2 has close relation with the initiation and progression of many diseases. Herein, we describe a novel red-emissive fluorescence probe (RhoB) for the visualization of H2O2 in living cells, tissues and animals. RhoB was constructed on the basis of a xanthene-based red-emissive dye, and displayed nearly no fluorescence. After the treatment with H2O2, RhoB can exhibit red fluorescence with the emission wavelength at 638 nm. RhoB exhibited highly sensitive and selective response to H2O2. Density functional theory (DFT) calculations were conducted to shed light on the optical properties of RhoB, and natural bond orbital (NBO) calculations demonstrate that the boron atom shows the highest positive electricity and further support the response mechanism. RhoB was successfully applied for imaging of exogenous and endogenous H2O2 in living cells, and also can be utilized for visualizing H2O2 in living tissues and animals.


Assuntos
Corantes Fluorescentes/química , Peróxido de Hidrogênio/metabolismo , Imagem Molecular/métodos , Xantenos/química , Animais , Sobrevivência Celular , Cor , Corantes Fluorescentes/metabolismo , Células HeLa , Humanos , Fígado/diagnóstico por imagem , Fígado/metabolismo , Camundongos , Xantenos/metabolismo
18.
Theranostics ; 8(3): 800-811, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29344307

RESUMO

Controlled release systems with capabilities for direct and real-time monitoring of the release and dynamics of drugs in living systems are of great value for cancer chemotherapy. Herein, we describe a novel dual turn-on fluorescence signal-based controlled release system (CDox), in which the chemotherapy drug doxorubicin (Dox) and the fluorescent dye (CH) are conjugated by a hydrazone moiety, a pH-responsive cleavable linker. CDox itself shows nearly no fluorescence as the fluorescence of CH and Dox is essentially quenched by the C=N isomerization and N-N free rotation. However, when activated under acidic conditions, CDox could be hydrolyzed to afford Dox and CH, resulting in dual turn-on signals with emission peaks at 595 nm and 488 nm, respectively. Notably, CDox exhibits a desirable controlled release feature as the hydrolysis rate is limited by the steric hindrance effect from both the Dox and CH moieties. Cytotoxicity assays indicate that CDox shows much lower cytotoxicity relative to Dox, and displays higher cell inhibition rate to cancer than normal cells. With the aid of the dual turn-on fluorescence at different wavelengths, the drug release dynamics of CDox in living HepG2 and 4T-1 cells was monitored in double channels in a real-time fashion. Importantly, two-photon fluorescence imaging of CDox in living tumor tissues was also successfully performed by high-definition 3D imaging. We expect that the unique controlled release system illustrated herein could provide a powerful means to investigate modes of action of drugs, which is critical for development of much more robust and effective chemotherapy drugs.


Assuntos
Antineoplásicos/farmacocinética , Doxorrubicina/farmacocinética , Liberação Controlada de Fármacos , Corantes Fluorescentes/farmacocinética , Células 3T3 , Animais , Antineoplásicos/administração & dosagem , Doxorrubicina/administração & dosagem , Feminino , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência por Excitação Multifotônica/métodos
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 188: 394-399, 2018 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-28755637

RESUMO

Hypochlorite is one of the important reactive oxygen species (ROS) and plays critical roles in many biologically vital processes. Herein, we present a unique ratiometric fluorescent probe (CBP) with an extremely large emission shift for detecting hypochlorite in living cells. Utilizing positively charged α,ß-unsaturated carbonyl group as the reaction site, the probe CBP itself exhibited near-infrared (NIR) fluorescence at 662nm, and can display strong blue fluorescence at 456nm when responded to hypochlorite. Notably, the extremely large emission shift of 206nm could enable the precise measurement of the fluorescence peak intensities and ratios. CBP showed high sensitivity, excellent selectivity, desirable performance at physiological pH, and low cytotoxicity. The bioimaging experiments demonstrate the biological application of CBP for the ratiometric imaging of hypochlorite in living cells.


Assuntos
Corantes Fluorescentes/química , Ácido Hipocloroso/análise , Sobrevivência Celular , Corantes Fluorescentes/síntese química , Células HeLa , Humanos , Fenômenos Ópticos , Espectrometria de Fluorescência , Fatores de Tempo
20.
Anal Chem ; 90(1): 998-1005, 2018 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-29212319

RESUMO

Discrimination of live and dead cells is an important task in biological, pathological, medical, and pharmaceutical studies. In this work, we have developed a novel fluorescent probe DACA that can discriminate live and dead cells in a dual-color mode for the first time. DACA can stain dead cells with blue fluorescence peaked at 440 nm, while it can also label live cells with orange emission peaked at 570 nm. Compared with one-color fluorescent probes, such a dual-color probe can efficiently avoid false positive results from cellular autofluorescence and misleading signals brought by inhomogeneous staining, and thus can supply more accurate information in biological applications. By means of DACA, the health status of tumor cells pretreated by H2O2 and ultraviolet radiation has been successfully detected and imaged. Moreover, DACA and the hydrolyzed product exhibit excellent two-photon properties. Live and dead cells, as well as the zebrafishes, have been discriminated with dual emission colors under one- and two-photon microscope. These results demonstrate that DACA is a powerful tool for dual-color distinguishing live and dead cells in vitro and in vivo.


Assuntos
Benzopiranos/química , Corantes Fluorescentes/química , Animais , Benzopiranos/síntese química , Benzopiranos/toxicidade , Morte Celular , Rastreamento de Células , Cor , Fluorescência , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Células HeLa , Humanos , Hidrólise , Raios Infravermelhos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Peixe-Zebra
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA