RESUMEN
Biomass-derived carbon dots (CDs) are non-toxic and fluorescently stable, making them suitable for extensive application in fluorescence sensing. The use of cheap and renewable materials not only improves the utilization rate of waste resources, but it is also drawing increasing attention to and interest in the production of biomass-derived CDs. Visual fluorescence detection based on CDs is the focus of current research. This method offers high sensitivity and accuracy and can be used for rapid and accurate determination under complex conditions. This paper describes the biomass precursors of CDs, including plants, animal remains and microorganisms. The factors affecting the use of CDs as fluorescent probes are also discussed, and a brief overview of enhancements made to the preparation process of CDs is provided. In addition, the application prospects and challenges related to biomass-derived CDs are demonstrated.
Asunto(s)
Biomasa , Carbono , Colorantes Fluorescentes , Carbono/análisis , Carbono/química , Puntos Cuánticos/análisis , Puntos Cuánticos/química , Plantas , Estructura MolecularRESUMEN
An efficient magneto-adsorbent composed of polyaniline blend poly(amidoamine) dendrimers modified graphene oxide quantum dots and magnetic Fe3O4 particles (Fe3O4@PANI-PSS/PAMAM-QGO) for magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) in environmental water was synthesized. Fe3O4@PANI-PSS/PAMAM-QGO exhibited exceptional adsorption property for most PAHs analytes. The nanocomposite sorbent demonstrated a ferromagnetic behavior of 17.457 emu g-1, which is adequate for subsequent use in MSPE. Key parameters affecting the processes of adsorption and desorption, including the sorbent amount, vortex adsorption time, vortex extraction time, sample volume, a solvent for desorption and the solvent volume were all examined and optimized. The performance of MSPE using Fe3O4@PANI-PSS/PAMAM-QGO as adsorbent for four PAHs, including fluoranthene, acenaphthene, phenanthrene and pyrene were studied through high performance liquid chromatography equipped with spectrofluorometer. Under the optimal conditions, Fe3O4@PANI-PSS/PAMAM-QGO showed a wide linearity of 10-1,000 ng mL-1, low detection limit (LOD) ranging from 1.92 to 4.25 ng mL -1 and high accuracy (recoveries of 93.6-96.5 %). Enrichment factors up to 185 were achieved. Furthermore, Fe3O4@PANI-PSS/PAMAM-QGO exhibited good recyclability (10 times, RSDs ≤ 5.35%), while maintaining its high efficiency in the extraction of PAHs. The proposed method was successfully applied for environmental samples. Recoveries ranging from 81.2 to 106.2 % were obtained, indicating a low matrix effect and the robustness of the optimized MSPE method. Based on these features and under the optimal extraction conditions, Fe3O4@PANI-PSS/PAMAM-QGO was demonstrated to be a successful tool for the rapid and sensitive extraction of PAHs in the samples.
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Compuestos de Anilina , Dendrímeros , Grafito , Poliaminas , Hidrocarburos Policíclicos Aromáticos , Puntos Cuánticos , Contaminantes Químicos del Agua , Hidrocarburos Policíclicos Aromáticos/análisis , Agua , Adsorción , Puntos Cuánticos/análisis , Solventes/análisis , Fenómenos Magnéticos , Extracción en Fase Sólida/métodos , Límite de Detección , Contaminantes Químicos del Agua/análisisRESUMEN
A composite magnetic adsorbent was developed by embedding graphene quantum dots (GQDs), silica-modified magnetite (Fe3O4-SiO2), and mesoporous carbon (MPC) into a molecularly imprinted polymer (GQDs/Fe3O4-SiO2/MPC/MIP). The adsorbent was applied to extract nonsteroidal anti-inflammatory drugs (NSAIDs) in milk. The MIP was formed via a sol-gel copolymerization using flurbiprofen, diflunisal, and mefenamic acid as template molecules, 3-aminopropyltriethoxysilane as a monomer, and tetraethyl orthosilicate as a cross-linker. GQDs and MPC enhanced affinity binding between NSAIDs and the adsorbent through π-π stacking, hydrogen bonding, and hydrophobic interaction. The Fe3O4-SiO2 nanoparticles embedded in the composite adsorbent enabled its rapid isolation from the sample solution. The extracted NSAIDs were quantified by high-performance liquid chromatography and exhibited good linearity from 1.0 to 100.0 µg L-1 for flurbiprofen and 0.5 to 100.0 µg L-1 for diflunisal and mefenamic acid, respectively. The limits of detection ranged from 0.5 to 1.0 µg L-1. Recoveries of NSAIDs from spiked milk samples ranged from 81.4 to 93.7%, with RSDs below 7%. The reproducibility of the fabricated adsorbent was good and in the optimal conditions, the developed adsorbent could be used for up to six extraction-desorption cycles.
Asunto(s)
Diflunisal , Flurbiprofeno , Grafito , Impresión Molecular , Puntos Cuánticos , Animales , Grafito/química , Leche/química , Polímeros Impresos Molecularmente , Extracción en Fase Sólida/métodos , Impresión Molecular/métodos , Puntos Cuánticos/análisis , Ácido Mefenámico/análisis , Dióxido de Silicio/química , Carbono , Diflunisal/análisis , Reproducibilidad de los Resultados , Antiinflamatorios no Esteroideos/análisisRESUMEN
In living organisms, redox reactions play a crucial role in the progression of disorders accompanied by the overproduction of reactive oxygen and reactive chlorine species, such as hydrogen peroxide and hypochlorous acid, respectively. We demonstrate that green fluorescence graphene quantum dots (GQDs) can be employed for revealing the presence of the hypochlorous acid in aqueous solutions and cellular systems. Hypochlorous acid modifies the oxygen-containing groups of the GQD, predominantly opens epoxide ring C-O-C, forms excessive C=O bonds and damages the carbonic core of GQDs. These changes, which depend on the concentration of the hypochlorous acid and exposure time, manifest themselves in the absorbance and fluorescence spectra of the GQD, and in the fluorescence lifetime. We also show that the GQD fluorescence is not affected by hydrogen peroxide. This finding makes GQDs a promising sensing agent for selective detecting reactive chlorine species produced by neutrophils. Neutrophils actively accumulate GQDs allowing to visualize cells and to examine the redox processes via GQDs fluorescence. At high concentrations GQDs induce neutrophil activation and myeloperoxidase release, leading to the disruption of GQD structure by the produced hypochlorous acid. This makes the GQDs a biodegradable material suitable for various biomedical applications.
Asunto(s)
Técnicas Biosensibles/métodos , Colorantes Fluorescentes , Ácido Hipocloroso , Neutrófilos , Puntos Cuánticos , Células Cultivadas , Colorantes Fluorescentes/análisis , Colorantes Fluorescentes/química , Colorantes Fluorescentes/metabolismo , Grafito/química , Humanos , Ácido Hipocloroso/análisis , Ácido Hipocloroso/metabolismo , Microscopía Fluorescente , Neutrófilos/química , Neutrófilos/metabolismo , Peroxidasa/metabolismo , Puntos Cuánticos/análisis , Puntos Cuánticos/química , Puntos Cuánticos/metabolismoRESUMEN
The link between the microbiome and cancer has led researchers to search for a potential probe for intracellular targeting of bacteria and cancer. Herein, we developed near infrared-emitting ternary AgInSe/ZnS quantum dots (QDs) for dual bacterial and cancer imaging. Briefly, water-soluble AgInSe/ZnS QDs were synthesized in a commercial kitchen pressure cooker. The as-synthesized QDs exhibited a spherical shape with a particle diameter of 4.5 ± 0.5 nm, and they were brightly fluorescent with a photoluminescence maximum at 705 nm. The QDs showed low toxicity against mouse mammary carcinoma (FM3A-Luc), mouse colon carcinoma (C26), malignant fibrous histiocytoma-like (KM-Luc/GFP) and prostate cancer cells, a greater number of accumulations in Staphylococcus aureus, and good cellular uptake in prostate cancer cells. This work is an excellent step towards using ternary QDs for diagnostic and guided therapy for prostate cancer.
Asunto(s)
Neoplasias de la Próstata/diagnóstico , Prostatitis/diagnóstico , Puntos Cuánticos/análisis , Staphylococcus aureus/aislamiento & purificación , Animales , Línea Celular Tumoral , Neoplasias del Colon/diagnóstico , Neoplasias del Colon/patología , Femenino , Histiocitoma Fibroso Maligno/diagnóstico , Histiocitoma Fibroso Maligno/patología , Humanos , Indio/química , Masculino , Neoplasias Mamarias Animales/diagnóstico , Neoplasias Mamarias Animales/patología , Ratones , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Prostatitis/diagnóstico por imagen , Prostatitis/patología , Puntos Cuánticos/química , Selenio/química , Plata/química , Staphylococcus aureus/patogenicidad , Sulfuros/química , Agua/química , Compuestos de Zinc/químicaRESUMEN
Research related to the development and application of luminescent nanoparticles (LNPs) for chemical and biological analysis and imaging is flourishing. Novel materials and new applications continue to be reported after two decades of research. This review provides a comprehensive and heuristic overview of this field. It is targeted to both newcomers and experts who are interested in a critical assessment of LNP materials, their properties, strengths and weaknesses, and prospective applications. Numerous LNP materials are cataloged by fundamental descriptions of their chemical identities and physical morphology, quantitative photoluminescence (PL) properties, PL mechanisms, and surface chemistry. These materials include various semiconductor quantum dots, carbon nanotubes, graphene derivatives, carbon dots, nanodiamonds, luminescent metal nanoclusters, lanthanide-doped upconversion nanoparticles and downshifting nanoparticles, triplet-triplet annihilation nanoparticles, persistent-luminescence nanoparticles, conjugated polymer nanoparticles and semiconducting polymer dots, multi-nanoparticle assemblies, and doped and labeled nanoparticles, including but not limited to those based on polymers and silica. As an exercise in the critical assessment of LNP properties, these materials are ranked by several application-related functional criteria. Additional sections highlight recent examples of advances in chemical and biological analysis, point-of-care diagnostics, and cellular, tissue, and in vivo imaging and theranostics. These examples are drawn from the recent literature and organized by both LNP material and the particular properties that are leveraged to an advantage. Finally, a perspective on what comes next for the field is offered.
Asunto(s)
Luminiscencia , Nanopartículas/análisis , Nanopartículas/química , Elementos de la Serie de los Lantanoides , Nanotubos de Carbono/análisis , Nanotubos de Carbono/química , Polímeros , Puntos Cuánticos/análisis , Puntos Cuánticos/químicaRESUMEN
Reaction centers (RCs) are the pivotal component of natural photosystems, converting solar energy into the potential difference between separated electrons and holes that is used to power much of biology. RCs from anoxygenic purple photosynthetic bacteria such as Rhodobacter sphaeroides only weakly absorb much of the visible region of the solar spectrum, which limits their overall light-harvesting capacity. For in vitro applications such as biohybrid photodevices, this deficiency can be addressed by effectively coupling RCs with synthetic light-harvesting materials. Here, we studied the time scale and efficiency of Förster resonance energy transfer (FRET) in a nanoconjugate assembled from a synthetic quantum dot (QD) antenna and a tailored RC engineered to be fluorescent. Time-correlated single-photon counting spectroscopy of biohybrid conjugates enabled the direct determination of FRET from QDs to attached RCs on a time scale of 26.6 ± 0.1 ns and with a high efficiency of 0.75 ± 0.01.
Asunto(s)
Transferencia de Energía , Transferencia Resonante de Energía de Fluorescencia/métodos , Nanoconjugados/química , Proteínas del Complejo del Centro de Reacción Fotosintética/química , Proteobacteria/química , Puntos Cuánticos/química , Nanoconjugados/análisis , Fotosíntesis , Proteínas del Complejo del Centro de Reacción Fotosintética/análisis , Puntos Cuánticos/análisis , Rhodobacter sphaeroides/química , Energía SolarRESUMEN
The carbon dots (CDs) from natural nanographite oxide mixture (NGO-MIX) and from its fraction NGO (3.5-10K) recovered after ultrafiltration and dialysis were analyzed by 3D-excitation/emission matrix and high-performance size exclusion chromatography (HPSEC) combined with online fluorescence and absorbance detections. HPSEC chromatograms obtained simultaneously with absorption within the wavelength range 200-500 nm and fluorescence detection at λexc/λem = 270/450 nm/nm showed that NGO-MIX sample is not homogeneous and consist of well resolved CDs fractions with different sizes, absorption spectra and distinct fluorescence and non-fluorescence properties. Despite the twice higher fluorescence intensity of fraction NGO (3.5-10K) compared to the NGO-MIX, some impurity of non-fluorescent components was detected by HPSEC. The absorbance spectra of chromatographic peaks, extracted from the data of multi-wavelength absorbance detector, demonstrated different combinations of absorbance maxima. It means that different chromatographic peaks correspond to sized and chemically different CDs fractions. This study demonstrated for the first time the possibility of separating oxidized nanographite into homogeneous free from non-fluorescent material CDs fractions with their simultaneous spectroscopic characterization.
Asunto(s)
Carbono , Técnicas de Química Analítica , Cromatografía en Gel , Puntos Cuánticos , Carbono/análisis , Carbono/aislamiento & purificación , Técnicas de Química Analítica/instrumentación , Técnicas de Química Analítica/métodos , Fluorescencia , Compuestos Orgánicos/análisis , Puntos Cuánticos/análisis , Análisis EspectralRESUMEN
Simple and visual quantitative detection of foodborne pathogens can effectively reduce the outbreaks of foodborne diseases. Herein, we developed a simple and sensitive quantum dot (QD)-based paper device for visual and quantitative detection of Escherichia coli (E. coli) O157:H7 based on immunomagnetic separation and nanoparticle dissolution-triggered signal amplification. In this study, E. coli O157:H7 was magnetically separated and labeled with silver nanoparticles (AgNPs), and the AgNP labels can be converted into millions of Ag ions, which subsequently quench the fluorescence of QDs in the paper strip, which along with the readout can be visualized and quantified by the change in length of fluorescent quenched band. Owing to the high capture efficiency and effective signal amplification, as low as 500 cfu mL-1 of E. coli O157:H7 could be easily detected by naked eyes. Furthermore, this novel platform was successfully applied to detect E. coli O157:H7 in spiked milk samples with good accuracy, indicating its potential in the detection of foodborne pathogens in real samples.
Asunto(s)
Escherichia coli O157/aislamiento & purificación , Colorantes Fluorescentes/análisis , Separación Inmunomagnética/instrumentación , Puntos Cuánticos/análisis , Tiras Reactivas/análisis , Animales , Infecciones por Escherichia coli/microbiología , Contaminación de Alimentos/análisis , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Nanopartículas del Metal/química , Leche/microbiología , Papel , Plata/químicaRESUMEN
Intracellular pH plays a significant role in all cell activities. Due to their precise imaging capabilities, fluorescent probes have attracted much attention for the investigation of pH-regulated processes. Detecting intracellular pH values with high throughput is critical for cell research and applications. In this work, hybrid semiconducting polymer dots (Pdots) were developed and characterized and were applied for cell imaging and exclusive ratiometric sensing of intracellular pH values. The reported Pdots were prepared by blending a synthesized block polymer (POMF) and a semiconducting polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEHPPV) to construct a fluorescence resonance energy transfer system for ratiometric sensing. Pdots showed many advantages, including high brightness, excellent photostability and biocompatibility, giving the pH probe high sensitivity and good stability. Our results proved the capability of POMF-MEHPPV Pdots for the detection of pH in living cells.
Asunto(s)
Técnicas Citológicas/métodos , Colorantes Fluorescentes/química , Polivinilos/química , Puntos Cuánticos/química , Transferencia Resonante de Energía de Fluorescencia , Colorantes Fluorescentes/análisis , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Puntos Cuánticos/análisisRESUMEN
Quantum dots (QDs) have attracted considerable attention as fluorescent probes for life sciences. The advantages of using QDs in fluorescence-based studies include high brilliance, a narrow emission band allowing multicolor labeling, a chemically active surface for conjugation, and especially, high photostability. Despite these advantageous features, the size of the QDs prevents their free transport across the plasma membrane, limiting their use for specific labeling of intracellular structures. Over the years, various methods have been evaluated to overcome this issue to explore the full potential of the QDs. Thus, in this review, we focused our attention on physical and biochemical QD delivery methods-electroporation, microinjection, cell-penetrating peptides, molecular coatings, and liposomes-discussing the benefits and drawbacks of each strategy, as well as presenting recent studies in the field. We hope that this review can be a useful reference source for researches that already work or intend to work in this area. Strategies for the intracellular delivery of quantum dots discussed in this review (electroporation, microinjection, cell-penetrating peptides, molecular coatings, and liposomes).
Asunto(s)
Colorantes Fluorescentes/administración & dosificación , Puntos Cuánticos/administración & dosificación , Animales , Péptidos de Penetración Celular/química , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/métodos , Electroporación/métodos , Colorantes Fluorescentes/análisis , Humanos , Liposomas/química , Microinyecciones/métodos , Puntos Cuánticos/análisisRESUMEN
The olfactory system is a driver of feeding behavior, whereby olfactory acuity is modulated by the metabolic state of the individual. The excitability of the major output neurons of the olfactory bulb (OB) can be modulated through targeting a voltage-dependent potassium channel, Kv1.3, which responds to changes in metabolic factors such as insulin, glucose, and glucagon-like peptide-1. Because gene-targeted deletion or inhibition of Kv1.3 in the periphery has been found to increase energy metabolism and decrease body weight, we hypothesized that inhibition of Kv1.3 selectively in the OB could enhance excitability of the output neurons to evoke changes in energy homeostasis. We thereby employed metal-histidine coordination to self-assemble the Kv1.3 inhibitor margatoxin (MgTx) to fluorescent quantum dots (QDMgTx) as a means to label cells in vivo and test changes in neuronal excitability and metabolism when delivered to the OB. Using patch-clamp electrophysiology to measure Kv1.3 properties in heterologously expressed cells and native mitral cells in OB slices, we found that QDMgTx had a fast rate of inhibition, but with a reduced IC50, and increased action potential firing frequency. QDMgTx was capable of labeling cloned Kv1.3 channels but was not visible when delivered to native Kv1.3 in the OB. Diet-induced obese mice were observed to reduce body weight and clear glucose more quickly following osmotic mini-pump delivery of QDMgTx/MgTx to the OB, and following MgTx delivery, they increased the use of fats as fuels (reduced respiratory exchange ratio). These results suggest that enhanced excitability of bulbar output neurons can drive metabolic responses.
Asunto(s)
Metabolismo Energético/fisiología , Canal de Potasio Kv1.3/antagonistas & inhibidores , Canal de Potasio Kv1.3/metabolismo , Obesidad/metabolismo , Bulbo Olfatorio/metabolismo , Puntos Cuánticos/metabolismo , Animales , Dieta Alta en Grasa/efectos adversos , Relación Dosis-Respuesta a Droga , Metabolismo Energético/efectos de los fármacos , Femenino , Canal de Potasio Kv1.3/análisis , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Obesidad/tratamiento farmacológico , Obesidad/etiología , Bulbo Olfatorio/química , Bulbo Olfatorio/efectos de los fármacos , Puntos Cuánticos/análisis , Venenos de Escorpión/farmacología , Venenos de Escorpión/uso terapéuticoRESUMEN
To achieve a rapid and facile quantitative evaluation of Sudan I illegally added in ketchup, fluorescent carbon quantum dots with excellent stability in acidic environments are required as the actual pH value of ketchup is close to 4.0. In this paper, we developed a green approach to prepare sulfur-doped carbon quantum dots (SCQDs) via hydrothermal treatment of lignin, isolated from pre-hydrolysis liquor, in sulfuric acid solution. The resultant SCQDs from lignin possessed sulfur-containing groups, which exhibited excellent fluorescence with a quantum yield up to 13.5% and good stability in acidic environments with a wide pH range of 0-5.0. Therefore, the SCQDs were successfully employed as a sensor to detect Sudan I in acidic solutions with excellent selectivity and sensitivity. The linear range for Sudan I was 0-40 µM, while the limit of detection was 0.12 µM. In addition, the fluorescent indicator paper functionalized with SCQDs also showed outstanding selectivity to Sudan I. The proposed SCQD sensing system not only displayed application potential for quantitative evaluation of Sudan I dye in practical samples, but also provided a way to convert lignin-based waste into highly valued nanoscale materials.
Asunto(s)
Carbono/química , Colorantes Fluorescentes/síntesis química , Lignina/síntesis química , Naftoles/síntesis química , Puntos Cuánticos/química , Ácidos Sulfúricos/química , Carbono/análisis , Colorantes Fluorescentes/análisis , Concentración de Iones de Hidrógeno , Lignina/análisis , Límite de Detección , Naftoles/análisis , Puntos Cuánticos/análisis , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Azufre/análisis , Azufre/química , Ácidos Sulfúricos/análisisRESUMEN
Despite the versatility of quantum dots (QDs) in optoelectronics and biomedical field, their toxicity risks remain a considerable hindrance for clinical applications. Cytotoxicity of Cadmium containing QDs is well documented and reveals that they are toxic to cells. Reports suggest that the presence of toxic elements at the QD core (e.g., cadmium, selenium) is responsible for its toxicity in in vivo and in vitro levels. Hence, here the toxicity of heavy metal free ZnSe/ZnS QDs on two scenarios were assessed, (i) HEK cells as in vitro system and (ii) Swiss Albino mice as in vivo model. Before toxicity analysis, QDs subjected to various optical and physico-chemical characterization methods such as absorption and emission spectra analysis, observation under U.V light, TEM, DLS, Zeta potential, FTIR, Raman and XPS spectra, ICP-OES, TGA and DTG curve. It is very necessary to characterize the synthesized QDs because their toxicity greatly influenced by the physico-chemical properties. On checking the vulnerability of HEK cells on exposure to ZnSe/ZnS QDs, the obtained results disclose that ZnSe/ZnS QDs showed merest impact on cellular viability at a concentration less than 100 µg/ml. Acute toxicity of 10 mg/kg ZnSe/ZnS QDs was studied in mice and no clinical or behavioural changes were observed. It did not induce any changes in haematological parameters and any loss of body or organ weight. Moderate pathological changes were evident only in the liver, all others organs like kidney, spleen and brain did not show any manifestations of toxicity. Current work lays substantial bedrock for safe biomedical and environmental application of ZnSe/ZnS QDs in near future.
Asunto(s)
Puntos Cuánticos/toxicidad , Selenio/toxicidad , Sulfuros/toxicidad , Compuestos de Zinc/toxicidad , Zinc/toxicidad , Animales , Peso Corporal/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Endocitosis/efectos de los fármacos , Células HEK293 , Humanos , Riñón/efectos de los fármacos , Riñón/patología , Hígado/efectos de los fármacos , Hígado/patología , Ratones , Tamaño de los Órganos/efectos de los fármacos , Puntos Cuánticos/análisis , Selenio/análisis , Bazo/efectos de los fármacos , Bazo/patología , Sulfuros/análisis , Pruebas de Toxicidad , Zinc/análisis , Compuestos de Zinc/análisisRESUMEN
Indium phosphide/zinc sulfate (InP/ZnS) quantum dots (QDs) are presumed to be less hazardous than those that contain cadmium. However, the toxicological profile has not been established. The present study investigated the acute toxicity of InP/ZnS QDs with different surface modifications (COOH, NH2, and OH) in mice after pulmonary aerosol inhalation. InP/ZnS QDs were able to pass through the blood-gas barrier and enter the circulation, and subsequently accumulated in major organs. No obvious changes were observed in the body weight or major organ coefficients. Red blood cell counts and platelet-related indicators were in the normal range, but the proportion of white blood cells was altered. The InP/ZnS QDs caused varying degrees of changes in some serum markers, but no histopathological abnormalities related to InP/ZnS QDs treatment was observed in major organs except that hyperemia in alveolar septa was found in lung sections. These results suggested that the effects of respiratory exposure to InP/ZnS QDs on the lungs need to be fully considered in future biomedical application although the overall toxicity of quantum dots is relatively low.
Asunto(s)
Pulmón , Puntos Cuánticos , Administración por Inhalación , Animales , Peso Corporal/efectos de los fármacos , Femenino , Indio/administración & dosificación , Indio/farmacocinética , Indio/toxicidad , Riñón/efectos de los fármacos , Riñón/metabolismo , Riñón/patología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Pulmón/patología , Ratones , Ratones Endogámicos BALB C , Microscopía Fluorescente , Fosfinas/administración & dosificación , Fosfinas/farmacocinética , Fosfinas/toxicidad , Puntos Cuánticos/administración & dosificación , Puntos Cuánticos/análisis , Puntos Cuánticos/metabolismo , Puntos Cuánticos/toxicidad , Propiedades de Superficie , Distribución Tisular , Sulfato de Zinc/administración & dosificación , Sulfato de Zinc/farmacocinética , Sulfato de Zinc/toxicidadRESUMEN
Near-infrared quantum dots (NIR QDs) are promising candidate for the fluorescent probes due to their better penetration depth, long-lived luminescence with size-tunable photoluminescence wavelengths. Glutathione-coated silver sulfide quantum dots (GSH-Ag2S QDs) were synthesized using AgNO3 and Na2S in the aqueous media and they can give reaction with glutathione reductase (GR) and glutathione-s transferase (GST) enzymes as acting substrate analogue in vitro. Investigation of the toxicity of the nanomaterials are necessary to use them in the medical field and biomedical applications. Thus, in this study we investigated biocompatibility of the GSH-Ag2S QDs in vitro using 293 T and CFPAC-1 cell lines. Cell viability by MTT assay, light microscopy, fluorescence microscopy, oxidative stress enzyme activities and ICP-MS analysis were performed to evaluate the cytotoxicity and internalization of the GSH-Ag2S QDs. GSH-Ag2S QDs showed great biocompatibility with both cell lines and did not cause imbalance in the oxidative stress metabolism. The ultralow solubility product constant of Ag2S QDs (Ksp = 6.3 × 10-50) prevents release of Ag ions into the biological systems that is in agreement with data obtained by ICP-MS. In conclusion, this data prove potential of GSH-Ag2S QDs as a biocompatible optical probe to be used for the detection and/or targeting of GSH impaired diseases including cancer.
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Glutatión/metabolismo , Puntos Cuánticos/química , Puntos Cuánticos/metabolismo , Supervivencia Celular , Materiales Biocompatibles Revestidos/análisis , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Glutatión Reductasa/metabolismo , Células HEK293/efectos de los fármacos , Humanos , Ensayo de Materiales/métodos , Estrés Oxidativo , Puntos Cuánticos/análisis , Plata/química , Plata/metabolismo , Compuestos de Plata/químicaRESUMEN
Gel electrophoresis, which is a standard method for separation and analysis of macromolecules such as DNA, RNA and proteins, is applied for the first time to silicon (Si) quantum dots (QDs) for size separation. In the Si QDs studied, boron (B) and phosphorus (P) are simultaneously doped. Codoping induces a negative potential on the surface of a Si QD and makes it dispersible in water. Si QDs with different B and P concentrations and grown at different temperatures (950 °C-1200 °C) are studied. It is shown that native polyacrylamide gel electrophoresis can separate codoped Si QDs by size. The capability of gel electrophoresis to immobilize size-separated QDs in a solid matrix makes detailed analyses of size-purified Si QDs possible. For example, the photoluminescence (PL) studies of the dried gel of Si QDs grown at 1100 °C demonstrate that a PL spectrum of a Si QD solution with the PL maximum around 1.4 eV can be separated into more than 15 spectra with the PL maximum changing from 1.2 to 1.8 eV depending on the migration distance. It is found that the relationship between the PL peak energy and the migration distance depends on the growth temperature of Si QDs as well as the B and P concentration. For all the samples with different impurity concentrations and grown at different temperatures, a clear trend is observed in the relationship between the full width at half maximum (FWHM) and the peak energy of the PL spectra in a wide energy range. The FWHM increases with the increasing peak energy and it is nearly twice larger than those observed for undoped Si QDs. The large PL FWHM of codoped Si QDs suggests that excitons are further localized in codoped Si QDs due to the existence of charged impurities.
Asunto(s)
Electroforesis en Gel de Poliacrilamida , Puntos Cuánticos/química , Silicio/química , Boro/análisis , Boro/química , Interacciones Hidrofóbicas e Hidrofílicas , Luz , Luminiscencia , Tamaño de la Partícula , Fósforo/análisis , Fósforo/química , Puntos Cuánticos/análisis , Silicio/análisis , Solubilidad , Propiedades de Superficie , TemperaturaRESUMEN
Single quantum dot tracking (SQDT) is a powerful technique for interrogating biomolecular dynamics in living cells and tissue. SQDT has particularly excelled in driving discovery at the single-molecule level in the fields of neuronal communication, plasma membrane organization, viral infection, and immune system response. Here, we briefly characterize various elements of the SQDT analytical framework and provide the reader with a detailed set of executable commands to implement commonly used algorithms for SQDT data processing.
Asunto(s)
Puntos Cuánticos/análisis , Imagen Individual de Molécula/métodos , Algoritmos , Difusión , Puntos Cuánticos/químicaRESUMEN
Small, stable, and bright quantum dots (QDs) are of interest in many biosensing and biomedical imaging applications, but current methodologies for obtaining these characteristics can be highly specialized or expensive. We describe a straightforward, low-cost protocol for functionalizing poly(isobutylene-alt-maleic anhydride) (PIMA) with moieties that anchor to the QD surface (histamine), impart hydrophilicity [(2-aminoethyl)trimethylammonium chloride (Me3N+-NH2)], and provide a platform for biofunctionalization via click chemistry (dibenzocyclooctyne (DBCO)). Guidelines to successfully use this polymer for QD ligand exchange are presented, and an example of biofunctionalization with DNA is shown. Stable QD-DNA conjugates are obtained with high yield and without requiring additional purification steps.