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1.
J Hazard Mater ; 416: 125860, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492808

RESUMO

Facile synthesis of nano porous organic cages with small size and good fluorescence property is highly desirable, but still challenging and scarce for their sensing applications. Here we report a rapid room-temperature recrystallization method for the preparation of nano porous organic cages with ultra-small size as a fluorescent probe for copper ion. The prepared nano porous organic cages gave the diameter of 2.49 ± 0.04 nm, and exhibited stable emission at 535 nm with absolute quantum yield of 0.68%. On the basis of the coordination interaction and charge transfer between the nano porous organic cages and copper ion, a simple fluorescent probe for copper ion in aqueous solution was developed. The developed method gave a calibration function of QE = 0.4815lg[Cu2+] + 0.5847 (where QE is the quenching efficiency; [Cu2+] in µM) (R2 = 0.9987) in a concentration range of 0.1-2 µM, the limit of detection (3s) of 8 nM, and the relative standard deviation of 0.36% for 10 replicate determinations of 0.5 µM copper ion. The recoveries of spiked copper ion in tap water samples ranged from 96.8% to 103.0%. The proposed method possesses good sensitivity, selectivity and accuracy.


Assuntos
Cobre , Água , Fluorescência , Corantes Fluorescentes , Porosidade , Espectrometria de Fluorescência , Temperatura
2.
Nanoscale ; 13(29): 12546-12552, 2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34477613

RESUMO

A metal-organic framework (MOF) material was prepared from 2-aminoterephthalic acid and aluminum chloride with a solvothermal synthesis protocol. The as-prepared MOF material named NH2-MIL-53(Al) emitted a very intensive fluorescent (FL) signal after it was hydrolyzed in alkaline solution for releasing numerous FL ligands NH2-H2BDC. Thus it can be considered as a sensitive FL probe for studying biorecognition events. In this proof-of-principle work, a double-site recognition method was established to quantify Staphylococcus aureus (S. aureus) relying on the alkaline hydrolysis property of the MOF material. In particular, magnetic beads (MBs) modified with pig IgG were adopted for binding S. aureus based on the strong affinity between pig IgG and protein A on the bacterial surface. Meanwhile, MOF NH2-MIL-53(Al)-tagged teicoplanin (TEI) was adopted for tracing the target bacteria. By hydrolyzing the MOF material bound on the MBs to trigger the FL signal, S. aureus can be quantified with a dynamic range of 3.3 × 103-3.3 × 107 CFU mL-1 and a detection limit of 5.3 × 102 CFU mL-1 (3σ). The method can exclude efficiently the interference from other common bacteria. It has been applied to quantify S. aureus in saliva, pomegranate green tea, glucose injection and milk samples with satisfactory results, verifying the application potential for analyzing various types of real samples contaminated with S. aureus.


Assuntos
Estruturas Metalorgânicas , Infecções Estafilocócicas , Animais , Corantes Fluorescentes , Hidrólise , Infecções Estafilocócicas/diagnóstico , Staphylococcus aureus , Suínos
3.
Nanoscale ; 13(32): 13795-13808, 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34477654

RESUMO

Light-activated functional materials capable of remote control over duplex and G-quadruplex (G4) nucleic acids formation at the cellular level are still very rare. Herein, we report on the photoinduced macrocyclisation of a helicenoid quinoline derivative of binaphthol that selectively provides easy access to an unprecedented class of extended heteroaromatic structures with remarkable photophysical and DNA/RNA binding properties. Thus, while the native bisquinoline precursor shows no DNA binding activity, the new in situ photochemically generated probe features high association constants to DNA and RNA G4s. The latter inhibits DNA synthesis by selectively stabilizing G4 structures associated with oncogenic promoters and telomere repeat units. Finally, the light sensitive compound is capable of in cellulo photoconversion, localizes primarily in the G4-rich sites of cancer cells, competes with a well-known G4 binder and shows a clear nuclear co-localization with the quadruplex specific antibody BG4. This work provides a benchmark for the future design and development of a brand-new generation of light-activated target-selective G4-binders.


Assuntos
Corantes Fluorescentes , Quadruplex G , DNA , Ligantes , Telômero
4.
Nanoscale ; 13(32): 13835-13844, 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34477658

RESUMO

Herbal medicines are potential candidates for the treatment of various diseases, but their medication safety remains poorly regulated. Current screening methods for the herbal medicine-induced nephrotoxic effects include histological and serological assessments, which often fail to reflect the kidney dysfunction instantly. Here we report a ratiometric fluorescence approach for the rapid and facile screening of drug-induced acute kidney injury using chromophore-modified gold nanoclusters. These gold nanoclusters are highly sensitive to reactive oxygen species (ROS), with a detection limit of 14 nM for ˙OH. After passing through the glomerular filtration barrier, the gold nanocluster-based probes can quantify the fluctuation of the ROS level in the kidneys and evaluate the risk of drug-induced nephrotoxicity. We further employed nephrotoxic triptolide as the model drug and the screening of drug-induced early renal injury was demonstrated using the nanoprobes, which is unattainable by conventional diagnostic approaches. Our fluorescent probes also allow the identification of other nephrotoxic components from herbal medicine such as aristolochine, providing a high-throughput strategy for the screening of herbal supplement-induced nephrotoxicity.


Assuntos
Nanopartículas Metálicas , Preparações Farmacêuticas , Corantes Fluorescentes , Ouro , Nanopartículas Metálicas/toxicidade , Espectrometria de Fluorescência
5.
Nanoscale ; 13(31): 13294-13300, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34477735

RESUMO

Successful delivery of fluorescent nanodiamonds (FNDs) into the cytoplasm is essential to many biological applications. Other applications require FNDs to stay within the endosomes. The diversity of cellular uptake of FNDs and following endosomal escape are less explored. In this article, we quantify particle uptake at a single cell level. We report that FNDs enter into the cells gradually. The number of internalized FNDs per cell differs significantly for the cell lines we investigated at the same incubation time. In HeLa cells we do not see any significant endosomal escape. We also found a wide distribution of FND endosomal escape efficiency within the same cell type. However, compared with HeLa cells, FNDs in HUVECs can easily escape from the endosomes and less than 25% FNDs remained in the vesicles after 4 h incubation time. We believe this work can bring more attention to the diversity of the cells and provide potential guidelines for future studies.


Assuntos
Nanodiamantes , Endossomos , Corantes Fluorescentes , Células HeLa , Humanos
6.
Nanoscale ; 13(30): 13116-13128, 2021 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-34477795

RESUMO

Carbon dots (CDs) are strongly fluorescent advanced materials that are promising for applications in bio-imaging, sensors or luminescent displays. One of the most-widely used class of CDs is synthesized via an aqueous, bottom-up technique starting from citric acid (CA) and an amino-precursor. Very high fluorescence quantum yields (QY) are reported for the resulting CDs. The as-synthesized raw suspensions, however, are crude mixtures of many components: bare carbon cores, carbon cores functionalized with fluorophores, freely floating molecular fluorophores, and several other by-products. In this study, we synthesized CDs from CA and amino acid cysteine (Cys) hydrothermally and demonstrate a complete separation of all components by means of two step gradient chromatography. In the first step, the separation was carried out on a normal-pressure preparative silica-gel column to get sufficient amounts of material to investigate structure and optical properties of the collected fractions. This preparative gradient elution method enabled us to separate moderately-fluorescent CDs from freely floating molecular fluorophores, polymeric fluorophores and CDs with built-in fluorophores. Here, we evidenced that amorphous CDs co-exist with crystalline CDs in one and the same suspension and showed that the amount of crystalline CDs increases with the synthesis temperature. In the second step, we turned to high performance liquid chromatography (HPLC) to further improve and optimize the efficiency of purification and automate it. Via HPLC, we were able to well-separate of up to six components. Within this work, we laid the foundation for CD purification with the highest possible purity for aqueous, bottom-up synthesized CDs and quantified the true quantum yield of CDs.


Assuntos
Carbono , Pontos Quânticos , Cromatografia , Corantes Fluorescentes , Água
7.
Anal Chim Acta ; 1178: 338829, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482874

RESUMO

Rapid, convenient, sensitive and simultaneous detection of distinct enzymes is urgently needed for diagnosis, therapeutics and prognostic of related diseases. Here, a new strategy for simultaneous monitoring γ-glutamyl transpeptidase (GGT) and alkaline phosphatase (ALP) activity has been fabricated based on dual-emission carbon dots (CDs). CDs were prepared by solvothermal treatment of Actinidia chinensis, which presents two fluorescent emissions at 471 nm (blue channel) and 671 nm (red channel). GGT and ALP activity can be detected based on inner filter effect (IFE) and static quenching effect (SQE) of blue and red channels of CDs, respectively. Linear ranges were 2.5-90 U L-1 and 5-200 U L-1, and limit of detection (LOD) were 0.71 U L-1 and 1.2 U L-1 for GGT and ALP, respectively. Developed CDs can monitor GGT and ALP activity in human serum samples with satisfied recoveries (99.3%-108.6% for GGT, 98.4%-105.4% for ALP). Furthermore, the combination of CDs to sense GGT and ALP activity with OR logic gate can predict human health status. The design and application of dual-emission CDs can also be extended as promising tools to detect multianalytes using different channel signals.


Assuntos
Fosfatase Alcalina , Pontos Quânticos , Carbono , Corantes Fluorescentes , Humanos , Limite de Detecção , gama-Glutamiltransferase
8.
Anal Chim Acta ; 1178: 338794, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482876

RESUMO

Fluorescent materials with tunable optical properties are critical to their potential application. So far, the tuning of double-color luminescence has been easily achieved for many organic materials, but there are very few reports on multicolor luminescence materials. In this work, a multicolor emissions Schiff-base fluorescent compound 1,1'-{4,4'-Biphenyldiylbis[nitrilo(E)methylylidene]}di(2-naphthol) (BPDN) with an aggregation induced emission (AIE) characteristic was synthesized, and its luminescent characteristic was investigated. The BPDN molecules with low concentration in solution can emit faint light, but a new AIE phenomenon will appear when the BPDN molecules are aggregated in the solvent with low solubility or high concentration. The color and efficiency of the AIE of BPDN can be tuned by changing its aggregation state: the luminescence of the aggregate gradually redshifts (blue, green, to orange) as the solvent with poor solubility in the mixture increases or increasing the concentration of the BPDN. Based on the multicolor luminescence BPDN, a molecularly imprinted ratiometric fluorescent probe test strip (MIRF test strip) had been prepared and successfully applied to visual detection of pentachloronitrobenzene (PCNB). The color of test strip could change gradually from orange to yellow to green with the increase of the concentration of PCNB. This work shows the characteristic and application of multicolor luminescence BPDN.


Assuntos
Luminescência , Nitrobenzenos , Corantes Fluorescentes , Solventes
9.
Anal Chim Acta ; 1178: 338807, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482879

RESUMO

In this work, we have designed and synthesized a new fluorescent molecular probe, DPY comprising of pyrene-diacetylpyridine conjugate, which was found to be sensitive to hydrazine as well as protonation. DPY is characterised by a strong emission both in solution (λem = 530 nm) as well as in solid state (λem = 610 nm), attributed to intramolecular charge-transfer. The probe responds to hydrazine with a ratiometric fluorescence emission change from yellow to blue, due to chalcone cyclisation reaction of α, ß-unsaturated carbonyl group resulting in the pyrazoline compound, DPY-Hy, imparting a strong greenish-blue emission in solution. Further, the strong fluorescence emission of DPY in powder and thin film was quenched upon exposure to TFA, and revived upon exposure to TEA. For developing on-site detection protocol, when DPY was drop-casted on nonfluorescent silica plate a vivid naked-eye colour change from orange-red to dark blue was realized. Interestingly, in the aggregated state, DPY exhibited a broad range emission from green to orange in a mixed solvent system of THF:H2O. A plausible explanation of the photophysical events is substantiated with theoretical calculations.


Assuntos
Chalcona , Chalconas , Corantes Fluorescentes , Hidrazinas , Pirenos
10.
Curr Protoc ; 1(9): e222, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34492732

RESUMO

Technological advancements in fluorescence flow cytometry and an ever-expanding understanding of the complexity of the immune system have led to the development of large flow cytometry panels reaching up to 43 colors at the single-cell level. However, as panel size and complexity increase, so too does the detail involved in designing and optimizing successful high-quality panels fit for downstream high-dimensional data analysis. In contrast to conventional flow cytometers, full-spectrum flow cytometers measure the entire emission spectrum of each fluorophore across all lasers. This allows for fluorophores with very similar emission maxima but unique overall spectral fingerprints to be used in conjunction, enabling relatively straightforward design of larger panels. Although a protocol for best practices in full-spectrum flow cytometry panel design has been published, there is still a knowledge gap in going from the theoretically designed panel to the necessary steps required for panel optimization. Here, we aim to guide users through the theory of optimizing a high-dimensional full-spectrum flow cytometry panel for immunophenotyping using comprehensive step-by-step protocols. These protocols can also be used to troubleshoot panels when issues arise. A practical application of this approach is exemplified with a 24-color panel designed for identification of conventional T-cell subsets in human peripheral blood. © 2021 Malaghan Institute of Medical Research, Cytek Biosciences. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Preparation and evaluation of optimal spectral reference controls Support Protocol 1: Antibody titration Support Protocol 2: Changing instrument settings Basic Protocol 2: Unmixing evaluation of fully stained sample Basic Protocol 3: Evaluation of marker resolution Support Protocol 3: Managing heterogeneous autofluorescence Basic Protocol 4: Assessment of data quality using expert gating and dimensionality reduction algorithms.


Assuntos
Corantes Fluorescentes , Lasers , Citometria de Fluxo , Humanos , Imunofenotipagem , Subpopulações de Linfócitos T
11.
Sheng Wu Gong Cheng Xue Bao ; 37(8): 2678-2687, 2021 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-34472288

RESUMO

Fluorescence imaging has been widely used in the fields of biomedicine and clinical diagnosis. Compared with traditional fluorescence imaging in the visible spectral region (400-760 nm), near-infrared (NIR, 700-1 700 nm) fluorescence imaging is more helpful to improve the signal-to-noise ratio and the sensitivity of imaging. Highly-sensitive fluorescent probes are required for high-quality fluorescence imaging, and the rapid development of nanotechnology has led to the emergence of organic dyes with excellent fluorescent properties. Among them, organic fluorescent probes with the advantages of high safety, good biocompatibility, and high optical stability, are more favorable than inorganic fluorescent probes. Therefore, NIR fluorescence imaging assisted with organic fluorescent probes can provide more structural and dynamic information of biological samples to the researchers, which becomes a hot spot in the interdisciplinary research field of optics, chemistry and biomedicine. This review summarizes the application of NIR organic fluorescent probes in cervical cancer imaging. Several typical organic fluorescent probes (such as indocyanine green, heptamethine cyanine dye, rhodamine and polymer fluorescent nanoparticles) assisted NIR fluorescence imaging and their applications in cervical cancer diagnosis were introduced, and the future development and application of these techniques were discussed.


Assuntos
Nanopartículas , Neoplasias do Colo do Útero , Feminino , Corantes Fluorescentes , Humanos , Imagem Óptica , Polímeros , Neoplasias do Colo do Útero/diagnóstico por imagem
12.
Anal Chim Acta ; 1177: 338786, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34482889

RESUMO

Biological thiols importantly regulate the intracellular redox activity and metabolic level, but many of the developed probes for biothiols are facing difficulty in effectively distinguishing GSH from Cys/Hcy due to the similarity in mechanism. In this work, despite the previous pattern of "Logic Gate", we reported the concept of "Fluorescence Fusion" for the first time to achieve only one excitation-emission process. The exploited the probe, MZ-NBD, could quickly measure GSH in 10 min with a large Stokes shift (130 nm). Though the reacting mechanism was similar, only GSH could cause the "Fluorescence Fusion" with only one strong fluorescence response while Cys/Hcy caused two peaks. Adjusting the excitation wavelength could hardly split the fused peak into two. Though image recognition by artificial intelligence could easily distinguish the patterns of peaks, here we used the signal-treating method to realize the high selectivity towards GSH. Moreover, MZ-NBD could be utilized for rapid detection of GSH in living MCF-7 cells, which was more suitable for GSH than using the "Logic Gate" strategy. More than introducing a novel probe with the new concept, this work was meaningful as the linker of traditional reaction-based fluorescent probes and potential image recognition by artificial intelligence, thus led to various future researches in inter-disciplines.


Assuntos
Cisteína , Glutationa , Inteligência Artificial , Fluorescência , Corantes Fluorescentes , Glutationa/isolamento & purificação , Homocisteína , Humanos , Células MCF-7
13.
Se Pu ; 39(10): 1055-1064, 2021 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-34505427

RESUMO

“Seeing is believing” is the central philosophy of life science research, which runs through the continuous understanding of individual molecules, molecular complexes, molecular dynamic behavior, and the entire molecular network. Living and dynamic molecules are functional in nature; therefore, fluorescence microscopy has emerged as an irreplaceable tool in life science research. However, when fluorescence imaging is performed at the molecular level, some artificial signals may lead to erroneous experimental results. This obstacle is due to the limitation of the optical diffraction limit, and the fluorescence microscope cannot distinguish the target in the diffraction-limited space. Super-resolution fluorescence imaging technology breaks through the diffraction limit, allows visualization of biomolecules at the nanometer scale to the single-molecule level, and allows us to study the structure and dynamic processes of living cells with unprecedented spatial and temporal resolution. It has become a powerful tool for life science research and is gradually being applied to material science, catalytic reaction processes, and photolithography as well. The principle of super-resolution imaging technologies is different; therefore, it has different technical performances, thus limiting their specific technical characteristics and application scope. Current mainstream super-resolution imaging technologies can be classified into three types: structured illumination microscopy (SIM), stimulated emission depletion (STED), and single-molecule localization microscopy (SMLM). These microscopes use different complex technologies, but the strategy is the same and simple, i.e. two adjacent luminous points in a diffraction-limited space can be spatially resolved by time resolution. SIM has been used for three-dimensional real-time imaging in multicellular organisms; however, compared with other technologies, its lower horizontal and vertical resolutions need to be further optimized. STED is limited by its small imaging field of view and high photobleaching; however, the best time resolution can be considered at a high spatial resolution, and it has been proven that three-color STED imaging can be performed. In SMLM super-resolution imaging, the time resolution is affected by the time required to locate all fluorophores, which is closely related to the switching and luminescence properties of the fluorophore. With the improvement in horizontal and vertical resolution of imaging, the image acquisition speed, photobleaching characteristics, and the possibility of multi-color and dynamic imaging have increasingly become the key determinants of super-resolution fluorescence imaging. Thus far, the main use of super-resolution imaging technology has been focused on biological applications for studying structural changes less than 200 nm in dimension. In addition to the combination of structural and morphological characterization with biomolecular detection and identification, super-resolution imaging technology is rapidly expanding into the fields of interaction mapping, multi-target detection, and real-time imaging. In the latter applications, super-resolution imaging technology is particularly advantageous because of more flexible sample staining, higher labeling efficiency, faster and simpler readings, and gentler sample preparation procedures. In this article, we compare the principles of these three technologies and introduce their application progress in biology. We expect the results described herein will help researchers clarify the technical advantages and applicable application directions of different super-resolution imaging technologies, thus facilitating researchers in making reasonable choices in future research.


Assuntos
Imagem Óptica , Imagem Individual de Molécula , Corantes Fluorescentes , Microscopia de Fluorescência
14.
Analyst ; 146(18): 5747-5755, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34515708

RESUMO

A super simple ratiometric fluorescence nanosensor has been fabricated by controlling the ligands of CdZnTe quantum dots (QDs), allowing the sensitive and visual detection of silver ions (Ag+). The green-emitting L-cysteine-protected CdZnTe QDs (Lcys-CdZnTe QDs) had a specific response to Ag+ and were used as the reporting probe, while the red-emitting N-acetyl-L-cysteine-protected CdZnTe QDs (NAC-CdZnTe QDs) showed no obvious response to all tested metal ions and were selected as the reference probe. Simply mixing them without any encapsulated synthesis ultimately produced a time-saving, low-cost detection method, allowing the sensitive and visual detection of Ag+ in samples. The proposed nanosensor exhibited a linear range of 0.5-4.0 µM along with a detection limit of 0.17 µM, and has been successfully applied in real tap water and lake water samples. This nanosensor also showed obvious color changes in the detection process and has potential in visual semi-quantitative detection. Our approach may provide a general and feasible strategy for designing ratiometric fluorescence nanosensors, which will attract a wide range of interest in sensing-related fields.


Assuntos
Pontos Quânticos , Cádmio , Corantes Fluorescentes , Íons , Ligantes , Prata , Espectrometria de Fluorescência , Telúrio , Zinco
15.
Analyst ; 146(18): 5517-5527, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34515714

RESUMO

Reactive sulfur species (RSS) play pivotal roles in various pathological and physiological processes. There exists an intricate relevance in generation and metabolism among these substances. Although they are nucleophilic, there are still some differences in their reactivity. There are many methods to detect them by using reactive fluorescent probes, but the systematic study of their reactivity is still lacking. In our study, we designed a multiple reaction site fluorescent probe based on benzene conjugated benzopyrylium and NBD. The study revealed that besides both biothiols and hydrogen sulfide, sulfur dioxide (SO2) can cleave the ether bond. There are two reaction forms for GSH with low reactivity: cutting the ether bond and adding the conjugated double bond of benzopyrylium. Nevertheless, Cys/Hcy with higher activity can further rearrange with NBD after cutting the ether bond. In addition, SO2 can not only cleave the ether bond, but also continue to add the conjugated double bond of benzopyrylium. The above processes lead to multicolor emission of the probe, thus realizing the characteristic analysis of different sulfides. Thus the probe can be used for the detection of sulfide in mitochondria, and further for the imaging of sulfide in cells and zebrafish. This effective analysis method will provide a broad application prospect for practical applications.


Assuntos
Cisteína , Sulfeto de Hidrogênio , Animais , Corantes Fluorescentes , Glutationa , Células HeLa , Homocisteína , Humanos , Sulfetos , Peixe-Zebra
16.
Analyst ; 146(18): 5558-5566, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34515720

RESUMO

The single signal amplification strategy is significant for detecting various disease biomarkers but is restricted by its limited accuracy. The multi-signal and multi-mode methods have overcome this deficiency. Acid phosphatase (ACP) is an important intracellular enzyme but one-step cell imaging material-based probes are scarce for ACP. Herein, we designed a one-step self-assembled polymer probe using neutral red (NR), modified-(pyridoxal-5'-phosphate (PLP)) and Eu3+. The polymer exhibited non-emission and excellent stability. Upon the catalytic hydrolysis reaction of ACP, the polymer exhibited two strong fluorescence signals at 373 nm and 613 nm and an appreciable decline of absorbance at 395 nm. The probe has excellent selectivity and higher sensitivity with a limit of detection as low as 0.02 mU mL-1. It possesses favorable biocompatibility and has been successfully used to detect and image intracellular ACP in several living cells.


Assuntos
Fosfatase Ácida , Corantes Fluorescentes , Fluorescência , Corantes Fluorescentes/toxicidade
17.
Talanta ; 235: 122659, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517575

RESUMO

Sensitive detection of ß-galactosidase (ß-gal) is of great significance for early diagnosis of ovarian cancer. Fluorescent probes for detecting ß-gal have received great interest due to the non-invasiveness, excellent sensitivity, high temporal, and superior spatial resolution. However, most reported fluorescent sensors for ß-gal suffer from aggregation caused quenching effect when accumulated, and cannot discriminate ß-gal from other species, especially, Escherichia coliß-gal. Herein, we report the first aggregation-induced emission (AIE)-active fluorescent probe HBTTPAG, which achieves species-selective detection of ß-gal. Probe HBTTPAG can discriminate Aspergillus oryzae ß-gal from Escherichia coliß-gal, with high sensitivity (detection limit of 3.7 × 10-3 UmL-1), superior selectivity and low cytotoxicity. Furthermore, HBTTPAG is utilized to visualize endogenous ß-gal in lysosomes of SKOV-3 cells, as well as to detect ß-gal activity in ovarian cancer tissues. Notably, owing to the AIE-active, HBTTPAG realizes long-term (12 h) tracking ß-gal in ovarian cancer cells. This work provides a promising method for species-selective detection of ß-gal in preclinical.


Assuntos
Imagem Óptica , Neoplasias Ovarianas , Feminino , Corantes Fluorescentes , Humanos , Lisossomos , beta-Galactosidase
18.
Talanta ; 235: 122719, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517587

RESUMO

Here, a dual lock-and-key fluorescence probe was developed for visualizing the inflammatory process in myocardial H9C2 cells. The probe possessed two-photon properties, viscosity sensitivity, and hydrogen peroxide (H2O2) responsiveness. A thiocarbamate spacer between fluorophore and H2O2 responsive unit enabled the release of carbonyl sulfide (COS). This rapidly converts to the anti-inflammatory hydrogen sulfide (H2S) by the ubiquitous enzyme carbon anhydrase. The probe displayed a dual response towards hydrogen peroxide and viscosity in vitro. No obvious fluorescence changes were observed towards either hydrogen peroxide or viscosity alone. In cellular experiments, the probe demonstrated good biocompatibility, low toxicity, and was shown responses towards exogenous and endogenous hydrogen peroxide under viscosity conditions. LPS induced cell inflammation showed it was able to effectively alleviate the inflammation-caused damage by releasing H2S and eliminating H2O2. The new protocol demonstrates its promising to achieve diagnosis and treatment of cellular inflammatory process.


Assuntos
Corantes Fluorescentes , Sulfeto de Hidrogênio , Fluorescência , Células HeLa , Humanos , Peróxido de Hidrogênio , Inflamação/tratamento farmacológico , Viscosidade
19.
Talanta ; 235: 122735, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517602

RESUMO

Accumulative evidences have indicated that abnormal expression of microRNAs (miRNAs) is closely associated with many health disorders, making them be regarded as potentialbiomarkers for early clinical diagnosis. Therefore, it is extremely necessary to develop a highly sensitive, specific and reliable approach for miRNA analysis. Catalytic hairpin assembly (CHA) signal amplification is an enzyme-free toehold-mediated strand displacement method, exhibiting significant potential in improving the sensitivity of miRNA detection strategies. In this review, we first describe the potential of miRNAs as disease biomarkers and therapeutics, and summarize the latest advances in CHA signal amplification-based sensing strategies for miRNA monitoring. We describe the characteristics and mechanism of CHA signal amplification and classify the CHA-based miRNA sensing strategies into several categories based on the "signal conversion substance", including fluorophores, enzymes, nanomaterials, and nucleotide sequences. Sensing performance, limit of detection, merits and disadvantages of these miRNA sensing strategies are discussed. Moreover, the current challenges and prospects are also presented.


Assuntos
Técnicas Biossensoriais , MicroRNAs , Nanoestruturas , Catálise , Corantes Fluorescentes , Limite de Detecção , MicroRNAs/genética , Técnicas de Amplificação de Ácido Nucleico
20.
Talanta ; 235: 122771, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517629

RESUMO

Intracellular cysteine and glutathione was deemed as the most important reductants in the cell and played significant roles in the cellular homeostasis and redox adjustment. Here we developed a NIR fluorescent probe (HI) to detect and report the intracellular cysteine and glutathione, and monitor the development of the drug resistance of tumor. HI with both excited wavelength and emitting wavelength located within near infrared area showed no fluorescence in the normal physiological environment. However, when HI responded to cysteine and glutathione, strong NIR fluorescence could be turned on, which was linear dependent to the cysteine concentrations and the limited of detection was 0.18 µM. The response between HI and cysteine/glutathione demonstrated high specificity and no other amino acids showed influence or competition. The HPLC identification of the recognition results confirmed the response of acryloyloxy on the HI and active sulfhydryl on the cysteine/glutathione. DFT calculation of the HOMO and LUMO energy before and after response revealed the intramolecular charge transfer mechanism that induced the generation of the fluorescence. When HI was incubated with PATU-8988 and PATU-8988/Fu cell, the intracellular cysteine and glutathione could be clearly imaged and monitored by the enhanced fluorescence. Meanwhile, when HI was applied to the tumor-bearing mice, the drug resistance of tumor could be monitored and reported.


Assuntos
Cisteína , Corantes Fluorescentes , Animais , Resistência a Medicamentos , Corantes Fluorescentes/farmacologia , Glutationa , Camundongos , Espectrometria de Fluorescência
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