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1.
ACS Appl Mater Interfaces ; 13(37): 44086-44095, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34516075

RESUMO

Lipid droplets (LDs) play indispensable roles in numerous physiological processes; hence, the visualization of the dynamic behavior of LDs in living cells is of great importance in physiological and pathological research. In this article, the quantitative structure-activity relationship (QSAR) theory was employed as an effective design strategy for the development of organelle-targeting carbon dots (CDs). The lipid-water partition coefficient (Log P) of the QSAR was adopted as a key parameter to predict the cellular uptake and subcellular localization of CDs in live cells. By carefully adjusting the molecular structure and lipophilicity of the precursors, p-phenylenediamine-derivatized nucleolus-targeting hydrophilic CDs were converted to lipophilic CDs [4-piperidinoaniline (PA) CDs] with inherent LD-targeting performance. The PA CDs were able to indicate the dynamic behavior of LDs and visualize the changes of bisphenol A-induced nonalcoholic fatty liver disease-like changes in a cellular model. The QSAR strategy of CDs demonstrated here is expected to be increasingly exploited as a powerful design tool for developing various organelle-targeting CDs.

2.
Anal Chem ; 93(36): 12434-12440, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34473470

RESUMO

The ability to accurately diagnose cancer is the cornerstone of early cancer treatment. The mitochondria in cancer cells maintain a higher pH and lower polarity relative to that in normal cells. A probe that reports signals only when both conditions are met may provide a reliable method for cancer detection with reduced false positives. Here, we construct an AND logic gate fluorescent probe using mitochondrial microenvironments as inputs. Utilizing the hydrolysis of a coumarin scaffold, the probe generates fluorescence signals ("ON") only when high pH (>7.0) and low polarity conditions exist simultaneously. Additionally, the higher mitochondrial membrane potential in cancer cells provides an additional level of selectivity because probe has increased affinity for cancer cell mitochondria. These capabilities endow the probe with a high contrast fluorescence diagnosis ability of cancer at cellular and tissue levels (as high as 51.9 fold), which is far exceeding the clinic threshold of 2.0 fold.


Assuntos
Lógica , Neoplasias , Cumarínicos , Fluorescência , Corantes Fluorescentes , Hidrólise , Neoplasias/diagnóstico
3.
Int Immunopharmacol ; 100: 107991, 2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34438336

RESUMO

BACKGROUND: MicroRNAs (miRNAs) are involved in the regulation of osteoclast biology and several pathogenic progression. This study aimed to identify the role of miR-26a in osteoclastogenesis and orthodontically induced inflammatory root resorption(OIIRR). METHODS: Rat orthodontic tooth movement (OTM) model was established by ligating a closed coil spring between maxillary first molar and incisor, and 50 g orthodontic force was applied to move upper first molar to middle for 7 days. Human periodontal ligament (hPDL) cells were isolated from periodontium of healthy donors, and then subjected to compression force (CF) for 24 h to mimic an in vitro OTM model. The levels of associated factors in vivo and in vitro were measured subsequently. RESULT: The distance of tooth movement was increased and root resorption pits were occurred in rat OTM model. The expression of miR-26a was decreased in vivo and vitro experiments. CF treatment enhanced the secretion of inflammatory factors receptor activator of nuclear factor-kappa B ligand (RANKL) and IL-6, osteoclast marker levels, and the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts, while miR-26a overexpression reversed these results. Furthermore, miR-26a overexpression inhibited the osteoclastogenesis and rescued the root resorption in OTM rats through inhibition of Jagged1. Additionally, Runx1 could bind to miR-26a promoter and promote its expression, thereby suppressing the osteoclastogenesis. CONCLUSION: We concluded that Runx1/miR-26a/Jagged1 signaling axis restrained osteoclastogenesis and alleviated OIIRR.

4.
Adv Healthc Mater ; 10(14): e2002268, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34165910

RESUMO

Wound healing is an essential and complex biological process. Research into its mechanism and factors that influence its effectiveness has led to better treatments. Changes in the microenvironment are demonstrated to affect wound healing. Cell polarity is a significant microenvironment-related parameter that is associated with many physiological and pathological activities. However, dynamic changes in polarity during wound healing have not been investigated. Monitoring cell polarity during wound healing may open up a new avenue for developing better treatments. Here, a method is developed to monitor cell polarity that involved taking advantage of the fascinating optical properties and biocompatibility of carbon dots (CDs). Specifically, near-infrared (NIR) polarity-sensitive N-phenyl-p-phenylenediamine (PPh-CDs) are successfully prepared, which exhibit high sensitivity to polarity, with 509-fold stronger fluorescence in dioxane than in water. The PPh-CDs are successfully applied to monitor the changes of lysosomal polarity during starvation conditions. Using this method, dynamic changes of polarity during wound healing of zebrafish are monitored for the first time. Upon an amputation performed at the zebrafish tail, stronger PPh-CDs fluorescence appeared at the wound sites, and the intensity increased for 25 min and then gradually decreased. This report provides an important experimental basis for investigating wound healing by employing polarity-sensitive CDs.


Assuntos
Carbono , Pontos Quânticos , Animais , Corantes Fluorescentes , Espectrometria de Fluorescência , Cicatrização , Peixe-Zebra
5.
Analyst ; 146(2): 495-501, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33201941

RESUMO

Great progress has been made with lipid droplet targeting fluorescent probes in a wide range of biomedical fields. However, the Stokes shifts of most fluorescent probes are relatively small, leading to strong biological background fluorescence, poor signal-to-noise ratios, self-quenching in the commonly used microscopes and the need for in vivo imaging systems. In this manuscript, the ester substituent rotation of fluorophores was supposed to result in a large Stokes shift via steric hindrance effects and resonance effects. A lipid droplet targeting fluorescent probe 1 was achieved by simply appending a 4-substituted ester group onto the classic coumarin fluorophore. Probe 1 exhibited large Stokes shifts (122 to 184 nm) in both high polarity and weak polarity solvents with good lipophilicity and polarity responsive ability (3500 fold fluorescence enhancement). Probe 1 was suitable for washing-free imaging of lipid droplets in living cells with excellent specificity and rapidity (<2 min). Probe 1 was applied for distinguishing cancer cells from normal cells by taking advantage of the abnormalities of lipid droplets of cancer cells. Due to its huge Stokes shift, probe 1 can be used for in vivo tumor imaging by the excitation of a blue laser, which is important for biomedical research.


Assuntos
Engenharia , Ésteres/química , Corantes Fluorescentes/química , Gotículas Lipídicas/química , Imagem Óptica/métodos , Células Hep G2 , Humanos , Rotação
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 245: 118919, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32977107

RESUMO

Reduced nicotinamide adenine dinucleotide (NADH) and its phosphate ester (NADPH) participate in numerous metabolic processes in living cells as electron carriers. The levels of NADH and NADPH in a cell are closely related to its metabolic and pathological state. It is important to monitor the levels of NADH and NADPH in living cells and in vivo in real-time. This review mainly focuses on fluorescent probes developed for monitoring NADH and NADPH in living cells and in vivo, and classifies them according to the recognition units. These fluorescence probes can rapidly respond to changes in NADH and NADPH levels without interference from other biomolecules, both in cell culture and in vivo. These probes have been employed to monitor NADH and NADPH levels in living cells, tumor spheroids, and in vivo; moreover, some of them can be used to discriminate normal cells from cancer cells, and detect cancer cell death due to reductive stress induced by natural antioxidants. This review is expected to inspire the generation of novel fluorescent probes for the detection of NADH and NADPH, and stimulate more attention in the development of fluorescent probes based on carbon dots and nanoparticles, as well as metal complex-based, time-gated luminescent probes for monitoring NADH and NADPH in both living cells and in vivo.


Assuntos
Corantes Fluorescentes , NAD , Morte Celular , Células HeLa , Humanos , NADP
7.
Anal Chem ; 93(3): 1786-1791, 2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33373187

RESUMO

The lysosomes of cancer cells have lower pH and higher viscosity than those of normal cells. These features can be used as sensitive and selective markers for cancer diagnosis. In this work, a pH and viscosity dual responsive lysosome targeting fluorescent probe 1 was designed based on the transformation of amino- and imino- forms of pyronine and the twisted intramolecular charge shuttle (TICS) sensing mechanism. Live cancer cells and tumors were effectively distinguished from normal cells and organs through fluorescence imaging of probe 1, which indicated that probe 1 could serve as an effective tool for visualization of tumors at organ level with high selectivity.


Assuntos
Corantes Fluorescentes/química , Lisossomos/química , Imagem Óptica , Pironina/química , Células 3T3 , Animais , Linhagem Celular Tumoral , Corantes Fluorescentes/síntese química , Humanos , Concentração de Íons de Hidrogênio , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Pironina/análogos & derivados , Pironina/síntese química , Viscosidade
8.
Anal Chem ; 92(24): 16130-16137, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33237734

RESUMO

As vital important bioactive species, human serum albumin (HSA) and sulfur dioxide (SO2) are essential molecules in the organisms and act a pivotal part in many biological events. Although studies have shown that SO2-induced HSA radicals can cause oxidative damage, the underlying mechanism of the synergistic effect of HSA and SO2 in various diseases is obscure, mainly because of the lack of powerful tools that can simultaneously detect HSA and SO2 in living systems. In this work, we report a novel single-site, double-sensing fluorescent probe 1 for the simultaneous detection of HSA and SO2. The probe is based on our finding that HSA can catalyze a Michael addition reaction between the probe and SO2, which induces a change in fluorescence. Probe 1 can effectively entered the endoplasmic reticulum and can be used to image exogenously introduced and de novo synthesis of HSA in endoplasmic reticulum. Furthermore, the simultaneous detection of HSA and SO2 was realized for the first time with probe 1. More important, we observed that HSA still retains its activity to catalyze the Michael addition reaction of 1 and SO2 in living cells, which may provide a significant boost in the study of the role of HSA in medicine and pharmacy.


Assuntos
Albumina Sérica Humana/análise , Dióxido de Enxofre/análise , Catálise , Sobrevivência Celular , Corantes Fluorescentes/química , Células HeLa , Humanos , Albumina Sérica Humana/química , Albumina Sérica Humana/urina , Dióxido de Enxofre/química , Dióxido de Enxofre/urina
9.
Talanta ; 219: 121317, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887057

RESUMO

Long and real time imaging of cell membrane is very important for better understanding of cell performances in physiological and pathological processes. Nowadays, fluorescence probe analysis has become an indispensable tool for monitoring cell membrane. Herein, a novel fluorescent probe based on specific recognition of GABAA receptor was developed for imaging cell membrane. The probe synthesized in this work has been successfully applied to image different kinds of cell membrane with some advantages over the reported probes. Moreover, the probe also showed good superiority in the preliminary screening GABAA drugs.


Assuntos
Corantes Fluorescentes , Receptores de GABA-A , Membrana Celular , Imagem Óptica , Espectrometria de Fluorescência
10.
J Am Chem Soc ; 142(40): 17069-17078, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-32946690

RESUMO

Boron-dipyrromethenes (Bodipys), since first reported in 1968, have emerged as a fascinating class of dyes in the past few decades due to their excellent photophysical properties including bright fluorescence, narrow emission bandwidth, resistance to photobleaching, and environment insensitivity. However, typical Bodipys are highly lipophilic, which often results in nonfluorescent aggregates in aqueous solution and also severely limits their bioavailability to cells and tissues. In this work, based on a simple one-atom B → C replacement in the Bodipy scaffold, we present a new class of carbon-dipyrromethenes (Cardipys for short) fluorescent dyes with tunable emission wavelengths covering the visible and near-infrared regions. These Cardipys not only retain the excellent photophysical properties of conventional Bodipys but also show improved water solubility and photostability due to their cationic character. Moreover, the cationic character also makes them extremely easy to penetrate the cell membrane and specifically accumulate into mitochondria without resorting to any mitochondria-targeted groups. Interestingly, several Cardipys bearing active styryl groups could serve as fluorescent indicators to map cellular trafficking of the glutathione conjugates produced within mitochondria under the catalysis of glutathione S-transferase (GST), thus showing potential in either exploring the detoxification mechanism of the mitochondrial GST/GSH system or evaluating the drug resistance of cancer cells that is closely related with GST activity.


Assuntos
Carbono/química , Corantes Fluorescentes/química , Glutationa/química , Mitocôndrias/química , Porfobilinogênio/análogos & derivados , Células A549 , Compostos de Boro/química , Cátions/química , Membrana Celular/metabolismo , Membrana Celular/ultraestrutura , Movimento Celular , Técnicas Eletroquímicas , Glutationa Transferase/metabolismo , Humanos , Mitocôndrias/ultraestrutura , Estrutura Molecular , Imagem Óptica , Processos Fotoquímicos , Porfobilinogênio/química , Solubilidade , Solventes/química , Espectrometria de Fluorescência
11.
ACS Appl Mater Interfaces ; 12(28): 31738-31744, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32608958

RESUMO

Carbon dots (CDs) have been widely studied for their excellent properties. However, most of the prepared CDs only show strong emission in the blue to green region, which greatly limits the application of CDs in the biomedical field. In this report, a new design strategy of long-wavelength CDs was reported. The orange phenyl-CDs with good optical properties and biocompatibility were successfully prepared by changing the substituted group of the o-phenylenediamine and the main emission band of phenyl-CDs was in the far-red region. With the increase of polarity, the wavelength of phenyl-CDs red-shifts and the fluorescence intensity decreases, demonstrating their sensitive polarity response function. In addition, phenyl-CDs can achieve ultrafast target imaging of lysosome within 40 s through clathrin-mediated endocytosis. Finally, phenyl-CDs were successfully applied for monitoring lysosomal polarity induced by drugs, which is helpful in getting a better understanding of the physiological and pathological processes of lysosomes. This report provides an important theoretical basis for the rational design and precise synthesis of long-wavelength fluorescent CDs.


Assuntos
Carbono/química , Pontos Quânticos , Células HeLa , Humanos , Lisossomos/química , Espectrometria de Fluorescência
12.
Chem Commun (Camb) ; 56(56): 7718-7721, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32538383

RESUMO

A series of near-infrared and photostable Si-oxazine fluorescent dyes was synthesized using a simple three-step procedure, and one of their reduced products, i.e. hydro-Si-oxazine HSiO3, has been utilized to sensitively detect hypochlorous acid and peroxynitrite generation by phagocytes in inflamed and pulmonary fibrosis diseased mice with emission wavelength beyond 750 nm.


Assuntos
Ácido Hipocloroso/metabolismo , Imagem Óptica/métodos , Ácido Peroxinitroso/metabolismo , Animais , Corantes Fluorescentes/química , Técnicas In Vitro , Camundongos , Fagócitos/metabolismo , Fibrose Pulmonar/metabolismo , Células RAW 264.7
13.
Anal Chem ; 92(11): 7940-7946, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32406677

RESUMO

Monitoring the ATP levels in lysosomes in situ is crucial for understanding their involvement in various biological processes but remains difficult due to the interference of ATP in other organelles or the cytoplasm. Here, we report a lysosome-specific fluorescent carbon dot (CD), which can be used to detect ATP in acidic lysosomes with "off-on" changes of yellow fluorescence. These CDs were successfully applied in real-time monitoring of the fluctuating concentration of lysosomal ATP induced by drug stimulation (e.g., chloroquine, etoposide, and oligomycin). Because of the excellent specificity, these CDs are promising agents for drug screening and medical diagnostics through lysosomal ATP monitoring.


Assuntos
Trifosfato de Adenosina/análise , Carbono/química , Corantes Fluorescentes/química , Lisossomos/química , Pontos Quânticos/química , Animais , Corantes Fluorescentes/síntese química , Células Hep G2 , Humanos , Imagem Óptica , Células Tumorais Cultivadas , Peixe-Zebra
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 237: 118381, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32334324

RESUMO

RNA as a carrier of genetic information plays a critical role in various physiological processes. RNA-rich nucleolus is usually employed as an important biomarker for many malignant diseases. Herein, RNA-responsive fluorescent carbon dots (CDs) were synthesized by a simple microwave method. Due to the presence of cationic benzothiazolium groups in the CDs, a "turn-on" fluorescence signal was achieved between CDs and RNA. The CDs exhibit excellent RNA selectivity and a good linear relationship with a detection limit of 0.62 µg/mL. The small particle size, polarity sensitivity and RNA response behavior of CDs realized fast and wash-free nucleolus imaging effectively. Overall, these CDs provide a powerful potential tool for monitoring cell nucleus activity and elucidating RNA dynamics.


Assuntos
Nucléolo Celular , Corantes Fluorescentes/química , Pontos Quânticos/química , RNA/análise , Amilorida/farmacologia , Carbono/química , Membrana Celular/efeitos dos fármacos , Nucléolo Celular/química , Clorpromazina/farmacologia , Endocitose/efeitos dos fármacos , Endocitose/fisiologia , Corantes Fluorescentes/farmacocinética , Corantes Fluorescentes/toxicidade , Células HeLa , Células Hep G2 , Humanos , Limite de Detecção , Imagem Molecular/instrumentação , Imagem Molecular/métodos , Pontos Quânticos/metabolismo , RNA/química , RNA/metabolismo , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Fatores de Tempo , beta-Ciclodextrinas/farmacologia
15.
Adv Biosyst ; 4(3): e1900261, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32293145

RESUMO

Mitochondria are the powerhouse of the cell, which maintain the metabolism of living cells. Mitochondrial membrane potential (MMP) is the key parameter of mitochondria and represents cellular activity. The programmable MMP transformations, i.e., normal, decrease, and vanishing, are indicative mitochondria healthy/damaged/dead states. Therefore, methods for monitoring MMP are of great importance. In this work, carbon dots responsive to mitochondrial membrane potential (MMP-CDs) are prepared by a simple microwave method. The intracellular distribution of the MMP-CDs is dependent on the mitochondrial membrane potential. Three different spatiotemporally organelle distributions (mitochondria/lysosome/nucleus) of the MMP-CDs indicate three distinct MMP levels (normal/decrease/vanishing), which represent three different cell states (healthy/damaged/dead). The normal cells with high mitochondrial membrane potential causes the MMP-CDs to accumulate in the mitochondria due to the Nernstian effect. The MMP-CDs are released from the mitochondria and transported to the lysosome when cells are in apoptosis with the decreased mitochondrial membrane potential. In dead cells with a vanished mitochondrial membrane potential, the MMP-CDs are collocated with the nucleus due to the affinity with DNA. Thus, various cellular states can be visualized through the different localizations of the MMP-CDs. These MMP-CDs are successfully employed in the detection of autophagy and H2 O2 -induced mitochondria and mitochondrial membrane potential changes.

16.
Anal Chim Acta ; 1106: 207-215, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32145850

RESUMO

In this work, a novel bright yellow fluorescent carbon dots (CDs) was synthesized from N-methyl-1,2-phenylenediamine hydrochloride in ethanol solvent through the solvothermal method. The obtained carbon dots had no fluorescence in water, but could specifically light up in the cell which makes the staining process without washing. Interestingly, the imaging process can be performed by simply shaking the culture with the cells for only 1 min, indicating ultrafast and easy to operate fluorescence imaging. Moreover, the carbon dots with abundant amino functional groups had good lysosome targeting properties (the Pearson's correlation coefficient is 0.92) and could achieve the ultrafast lysosome imaging in cell and zebrafish and monitoring cell apoptosis status. This is the first lysosome targeting carbon dots that allows the combination of a short incubation at the second-level with wash-free process providing great potential for continuous observation lysosome in vivo.


Assuntos
Apoptose , Carbono/química , Corantes Fluorescentes/química , Imagem Óptica , Pontos Quânticos/química , Animais , Corantes Fluorescentes/síntese química , Células HeLa , Humanos , Lisossomos/química , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície , Peixe-Zebra/embriologia
17.
J Mater Chem B ; 8(4): 736-742, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31894833

RESUMO

Lysosomes are crucial dynamic organelles which play key roles in different cellular processes such as autophagy, endocytosis and phagocytosis. Thus, long-term and real-time lysosomal imaging is desirable and essential to understand the dynamics and biological functions of lysosomes. Herein, ultra-stable carbon dots (CDs) which have shown many advantages such as pH-independence, high water solubility, good photostability and high biocompatibility for lysosome labeling and long-term tracking were synthesized using a one-pot pyrolysis method via microwave irradiation. Compared with the commercial lysosome probe (LysoTracker™ Deep Red), the fluorescent CDs show superior resistance to photobleaching and the HeLa cells were stably labeled by CDs for over 48 h. In addition, the CDs could stain lysosomes in different cell lines with high specificity and track lysosomal movements. Furthermore, the CDs could stain not only lysosomes in living cells, but also lysosomes in drug-induced apoptotic cells and fixed cells, suggesting that they are suitable for lysosomal tracking under both physiological and toxicological processes. All these excellent properties could be attributable to the ultrastability of CDs, which can be employed for constructing nanoplatforms for other applications such as drug carriers and signal guiders in biological processes. This study provides not only a strategy to synthesize green fluorescent CDs for tracking lysosomes, but also a promising candidate for drug loading and signal guidance of biological processes.


Assuntos
Carbono/química , Corantes Fluorescentes/química , Lisossomos/química , Pontos Quânticos/química , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Teste de Materiais , Microscopia de Fluorescência , Micro-Ondas , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
18.
Analyst ; 144(24): 7457-7462, 2019 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-31710053

RESUMO

Glutathione (GSH) plays crucial roles in various physiological and pathological processes. The fluctuation of the GSH level is closely associated with a variety of diseases and cellular functions. Hence, it is important to real-time monitor the fluctuation of GSH in living cells. In this work, we presented a rhodol-hybridized hemicyanine fluorophore (RdH) as a selective, rapid-response, ratiometric, and reversible fluorescent probe for intracellular GSH (t1/2 = 89 ms, Kd = 1.42 mM). The imaging assays in living cells revealed that RdH could be used to real-time monitor GSH dynamics in A549 cells under a laser scanning confocal microscope by ratiometric fluorescence changes.


Assuntos
Carbocianinas/química , Corantes Fluorescentes/química , Glutationa/metabolismo , Imagem Óptica , Xantonas/química , Células A549 , Humanos , Espectrometria de Fluorescência
19.
Small ; 15(48): e1901507, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31168960

RESUMO

As novel fluorescent nanomaterials, carbon dots (CDs) exhibit excellent photostability, good biocompatibility, and high quantum yield (QY). Their superior properties make them promising candidates for biomedical assays and therapy. Among them, the red-emission (>600 nm) CDs have attracted increasing attention in the past years due to their little damage to the biological matrix, deep tissue penetration, and minimum autofluorescence background of biosamples. This Review, summarizes the recent progress of far-red to near-infrared (NIR) CDs from the preparation and their biological applications. The challenges in designing far-red and NIR CDs and their further applications in biomedical fields are also discussed.


Assuntos
Biotecnologia , Carbono/química , Raios Infravermelhos , Pontos Quânticos/química , Imagem Óptica , Solventes/química
20.
Anal Chem ; 91(14): 9259-9265, 2019 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-31204808

RESUMO

Carbon dots (CDs) are emerging as powerful tools for biosensing and bioimaging because of their intrinsic properties such as abundant precursors, facile synthesis, high biocompatibility, low cost, and particularly robust tunability and stability. In this work, a new type of CDs was prepared from m-phenylenediamine and folic acid by hydrothermal method. Interestingly, the as-prepared CDs show blue emission in non-hydrogen-bonding solution, whereas robust green emission in hydrogen-bonding solution. Based on this phenomenon, a novel fluorescence sensing mechanism named as hydrogen-bonding-induced emission (HBIE) was proposed. The HBIE-CDs have large Stokes shift (141 nm) in water, good biocompatibility, and ultrasmall size, which facilitates their translocation into living cells. Very importantly, the as-prepared HBIE-CDs show strong affinity toward nucleic acid without interference from other biological species. After binding with DNA/RNA through hydrogen bond, as high as 6-fold green fluorescence enhancement of HBIE-CDs was observed. Since the nucleus is rich in DNA/RNA, these HBIE-CDs were successfully used for rapid and, especially, wash-free subcellular in situ imaging of the nucleus in living cells in a fluorescence turn on mode, which has a great practicability to be used for nucleus imaging in bioanalytical studies and clinical applications.


Assuntos
Núcleo Celular/metabolismo , Corantes Fluorescentes/química , Pontos Quânticos/química , Carbono/química , DNA/metabolismo , Fluorescência , Corantes Fluorescentes/metabolismo , Corantes Fluorescentes/toxicidade , Ácido Fólico/química , Células HeLa , Humanos , Ligação de Hidrogênio , Microscopia de Fluorescência/métodos , Fenilenodiaminas/química , Pontos Quânticos/metabolismo , Pontos Quânticos/toxicidade , RNA/metabolismo
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