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1.
Photochem Photobiol Sci ; 20(1): 183-188, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33721239

RESUMEN

A hypothesis is proposed to explain the increased detrimental effect of COVID-19 for Black, Asian and Minority Ethnic (BAME) men and women compared to Caucasian individuals. This is based on the differing photochemistry of phaeomelanin in fair skin and eumelanin in dark/black skin. It is suggested that a range of reactive oxygen species, including, singlet oxygen and the superoxide radical anion, derived via direct photolysis of phaeomelanin, may escape the melanocyte and cause subsequent damage to the SARS-CoV-2 virus. It is further suggested that (large) carbon and sulphur peroxy radicals, from oxygen addition to radicals formed by carbon-sulphur bond cleavage, may assist via damage to the cell membranes. It is also speculated that light absorption by phaeomelanin and the subsequent C-S bond cleavage, leads to release of pre-absorbed reactive oxygen species, such as singlet oxygen and free radicals, which may also contribute to an enhanced protective effect for fair-skinned people.


Asunto(s)
/patología , Grupos Étnicos , Procesos Fotoquímicos , /etnología , Carbono/química , Femenino , Radicales Libres/química , Humanos , Luz , Masculino , Melaninas/química , Fotólisis , Oxígeno Singlete/química , Oxígeno Singlete/metabolismo , Piel/metabolismo , Azufre/química , Superóxidos/química , Superóxidos/metabolismo
2.
Int J Nanomedicine ; 16: 2045-2058, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33731993

RESUMEN

Background: Carbon dots (CDs) emitting near-infrared fluorescence were recently synthesized from green leaves. However, the Hg2+ detection of CDs was limited because of the insufficient water solubility, low fluorescence and poor stability. Methods: Dual fluorescence emission water-soluble CD (Dual-CD) was prepared through a solvothermal method from holly leaves and low toxic PEI1.8k. PEG was further grafted onto the surface to improve the water solubility and stability. Results: The Dual-CD solution can emit 487 nm and 676 nm fluorescence under single excitation and exhibit high quantum yield of 16.8%. The fluorescence at 678 nm decreased remarkably while the emission at 470 nm was slightly affected by the addition of Hg2+. The ratiometric Hg2+ detection had a wide linear range of 0-100 µM and low detection limit of 14.0 nM. In A549 cells, there was a good linear relation between F487/F676 and the concentration of Hg2+ in the range of 0-60 µM; the detection limit was 477 nM. Furthermore, Dual-CD showed visual fluorescence change under Hg2+. Conclusion: Dual-CD has ratiometric responsiveness to Hg2+ and can be applied for quantitative Hg2+ detection in living cells.


Asunto(s)
Carbono/química , Ilex/química , Mercurio/análisis , Hojas de la Planta/química , Puntos Cuánticos/química , Agua/química , Células A549 , Supervivencia Celular , Humanos , Iones , Fenómenos Ópticos , Espectroscopía de Fotoelectrones , Puntos Cuánticos/ultraestructura , Espectrometría de Fluorescencia , Espectrofotometría Ultravioleta
3.
Int J Nanomedicine ; 16: 2203-2217, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33762821

RESUMEN

Background: It is well known that smoking is harmful to health; however, it can also ameliorate anxiety. To date, it is unclear whether any nanoparticles found in cigarette mainstream smoke (CS) contribute to this effect. Aim: The aim of this study was to assess the particle composition of CS to identify novel anti-anxiety components. Methods: Carbon dots (CDs) from CS (CS-CDs) were characterised using high-resolution transmission electron microscopy, Fourier-transform infrared, ultraviolet, fluorescence, X-ray photoelectron spectroscopy, X-ray diffraction and high-performance liquid chromatography. The anti-anxiety effects of CS-CDs in mouse models were evaluated and confirmed with the elevated plus maze and open-field tests. Results: The quantum yield of CS-CDs was 13.74%, with a composition of C, O, and N. In addition, the surface groups contained O-H, C-H, C=O, C-N, N-H, C-O-C, and COO- bonds. Acute toxicity testing revealed that CS-CDs had low in vitro and in vivo toxicity within a certain concentration range. The results of the elevated plus maze and open-field tests showed that CS-CDs had a significant anti-anxiety effect and a certain sedative effect in mice. The mechanism of these effects may be related to the decrease in glutamate levels and promotion of norepinephrine production in the mouse brain, and the decrease in dopamine in mouse serum due to CS-CDs. Conclusion: CS-CDs may have anti-anxiety and certain sedative effects. This study provides a new perspective for a more comprehensive understanding of the components, properties, and functions of CS. Furthermore, it offers a novel target for the development of smoking cessation treatments, such as nicotine replacement therapy.


Asunto(s)
Conducta Animal , Carbono/química , Fumar Cigarrillos/efectos adversos , Sistema Endocrino/metabolismo , Neurotransmisores/metabolismo , Puntos Cuánticos/química , Agua/química , Hormona Adrenocorticotrópica/sangre , Animales , Ansiedad/sangre , Ansiedad/patología , Encéfalo/metabolismo , Encéfalo/patología , Cromatografía Líquida de Alta Presión , Corticosterona/sangre , Hormona Liberadora de Corticotropina/sangre , Dopamina/sangre , Masculino , Ratones , Ratones Endogámicos ICR , Espectroscopía de Fotoelectrones , Puntos Cuánticos/ultraestructura , Células RAW 264.7 , Espectrometría de Fluorescencia , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Pruebas de Toxicidad Aguda , Difracción de Rayos X
4.
J Colloid Interface Sci ; 592: 342-348, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33677194

RESUMEN

Facemasks are considered the most effective means for preventing infection and spread of viral particles. In particular, the coronavirus (COVID-19) pandemic underscores the urgent need for developing recyclable facemasks due to the considerable environmental damage and health risks imposed by disposable masks and respirators. We demonstrate synthesis of nanoporous membranes comprising carbon dots (C-dots) and poly(vinylidene fluoride) (PVDF), and demonstrate their potential use for recyclable, self-sterilized facemasks. Notably, the composite C-dot-PVDF films exhibit hydrophobic surface which prevents moisture accumulation and a compact nanopore network which allows both breathability as well as effective filtration of particles above 100 nm in diameter. Particularly important, self-sterilization occurs upon short solar irradiation of the membrane, as the embedded C-dots efficiently absorb visible light, concurrently giving rise to elevated temperatures through heat dissipation.


Asunto(s)
/prevención & control , Carbono/química , Máscaras/virología , Nanoporos , Esterilización , Luz Solar , /transmisión , Humanos
5.
Ecotoxicol Environ Saf ; 213: 112043, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33588189

RESUMEN

We describe a green new method for the synthesis of water-soluble photoluminescent carbon dots (CDs) that were functionalized with methimazole (MTZ) and applied to determine Hg2+ based on the fluorescence extinction. Starch obtained from rice was used as a natural source for the production of CDs by hydrothermal treatment. Also, it was proposed a factorial design to optimize the parameters for CD synthesis and the results showed that the luminescence intensity is a function of temperature and not of the heating time in the hydrothermal process. The synthesized CDs were characterized using fluorescence techniques, Fourier transform infrared spectroscopy (FTIR), and UV-Vis spectroscopy. Through transmission electron microscopy (TEM) and dynamic light scattering (DLS), it was found the formation of CDs on a nanometer scale with an average size of 11 nm. The functionalization with MTZ, eliminated all interferences from other metals, indicating a selective response to Hg2+ ions. The method was applied to Hg2+ determination in waters. Under optimal conditions, was obtained a limit of detection of 1.8 × 10-7 mol L-1 with a linear range from 3.3 × 10-7 to 50.0 × 10-6 mol L-1. Therefore, the proposed method can be considered a simple, selective, and precise alternative that minimizes the number of reagents used for Hg2+ determination in natural waters, and can be applied on a large scale in environmental analyzes.


Asunto(s)
Monitoreo del Ambiente/métodos , Mercurio/análisis , Metimazol/química , Puntos Cuánticos/química , Carbono/química , Fluorescencia , Colorantes Fluorescentes/química , Iones/química , Espectrometría de Fluorescencia/métodos , Espectroscopía Infrarroja por Transformada de Fourier , Almidón
6.
Food Chem ; 349: 129160, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33550018

RESUMEN

Indigo carmine (IC) dye is hazardous and allergenic for humans even though it has been excessively used in a wide range of industries. Therefore, the quantitative determination of IC is still challenging. Herein, for the first time, we have developed fluorometric and colorimetric dual-mode nanoprobe derived from the ion-pair association complex between the negatively charged IC and positively charged N@C-dots in pH = 3.0. Consequently, the binding between N@C-dots and IC resulted in cyan blue and quenching of N@C-dots fluorescence. The dependence of the fluorescence response on IC concentrations was linear over the range of 0.73-10.0 µM (R2 = 0.9989) with LOD of 0.24 µM. On the other hand, the linearity of the colorimetric method ranged from 9.97 to 80.0 µM (R2 = 0.9986) with LOD of 3.3 µM. The sensor was applied for estimation of IC in fruit juice and soft drink without the need for exhaustive extraction steps.


Asunto(s)
Bebidas/análisis , Carbono/química , Análisis de los Alimentos/métodos , Contaminación de Alimentos/análisis , Carmin de Índigo/análisis , Límite de Detección , Nitrógeno/química , Colorimetría , Fluorometría , Humanos
7.
Food Chem ; 349: 129202, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33582540

RESUMEN

In this work, we propose a electrochemical enzyme-free glucose sensor by direct growth of conductive Ni/Co bimetal MOF on carbon cloth [Ni/Co(HHTP)MOF/CC] via a facile hydrothermal method. Due to excellent conductivity between Ni/Co(HHTP)MOF and CC, synergic catalytic effect of Ni and Co elements, the Ni/Co(HHTP)MOF/CC not only provides larger surface area and more effective active sites, but also boosts the charge transports and electro-catalytic performance. Under optimized conditions, the Ni/Co(HHTP)MOF/CC shows excellent activity with a linear range of 0.3 µM-2.312 mM, a low detection limit of 100 nM (S/N = 3), a fast response time of 2 s and a high sensitivity of 3250 µA mM-1 cm-2. Furthermore, the Ni/Co(HHTP)MOF/CC was successfully applied for the detection of glucose in real serum and beverages with competitive performances. This facile and cost-effective method provides a novel strategy for monitoring of glucose in biological and food samples.


Asunto(s)
Bebidas/análisis , Carbono/química , Cobalto/química , Electroquímica/instrumentación , Glucosa/análisis , Estructuras Metalorgánicas/química , Níquel/química , Glucemia/análisis , Catálisis , Conductividad Eléctrica , Humanos , Límite de Detección
8.
ACS Appl Mater Interfaces ; 13(7): 7854-7864, 2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33560115

RESUMEN

Graphene field-effect transistors (GFETs) are suitable building blocks for high-performance electrical biosensors, because graphene inherently exhibits a strong response to charged biomolecules on its surface. However, achieving ultralow limit-of-detection (LoD) is limited by sensor response time and screening effect. Herein, we demonstrate that the detection limit of GFET biosensors can be improved significantly by decorating the uncovered graphene sensor area with carbon dots (CDs). The developed CDs-GFET biosensors used for exosome detection exhibited higher sensitivity, faster response, and three orders of magnitude improvements in the LoD compared with nondecorated GFET biosensors. A LoD down to 100 particles/µL was achieved with CDs-GFET sensor for exosome detection with the capability for further improvements. The results were further supported by atomic force microscopy (AFM) and fluorescent microscopy measurements. The high-performance CDs-GFET biosensors will aid the development of an ultrahigh sensitivity biosensing platform based on graphene for rapid and early diagnosis of diseases.


Asunto(s)
Técnicas Biosensibles , Carbono/química , Exosomas/química , Puntos Cuánticos/química , Transistores Electrónicos , Tamaño de la Partícula , Propiedades de Superficie
9.
ACS Appl Mater Interfaces ; 13(7): 8754-8763, 2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33590754

RESUMEN

For sustainability and environmental friendliness, the renewable biomaterials including cellulose have been widely used in flexible electronics, such as pressure sensors. Herein, the carbonized bacterial nanocellulose with excellent conductivity and wood-derived cellulose nanofibrils are combined to prepare the aerogel through directional ice-templating and freeze-drying. The obtained composite aerogel, which has a porous structure and aligned channels, is further employed as an active layer to prepare the resistive-type pressure sensor on a paper substrate. This pressure sensor exhibits remarkable flexibility, fast response, reliability, and especially adjustable sensitivity in a wide pressure range (0-100 kPa). In addition, the sensor's working mechanism and potential applications, such as motion detection, footstep recognition, and communication with smartphones via Bluetooth, are also well demonstrated. Moreover, this work provides novel insights into the development of green pressure sensors and the utilization of sustainable natural biomaterials in high-tech fields.


Asunto(s)
Bacterias/química , Carbono/química , Monitoreo Fisiológico , Nanofibras/química , Teléfono Inteligente , Celulosa/química , Geles/química , Humanos , Tamaño de la Partícula , Porosidad , Presión , Propiedades de Superficie , Madera/química
10.
Nat Commun ; 12(1): 812, 2021 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-33547279

RESUMEN

Carbon dots (CDs) are photoluminescent nanomaterials with wide-ranging applications. Despite their photoactivity, it remains unknown whether CDs degrade under illumination and whether such photodegradation poses any cytotoxic effects. Here, we show laboratory-synthesized CDs irradiated with light degrade into molecules that are toxic to both normal (HEK-293) and cancerous (HeLa and HepG2) human cells. Eight days of irradiation photolyzes 28.6-59.8% of the CDs to <3 kilo Dalton molecules, 1431 of which are detected by high-throughput, non-target high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Molecular network and community analysis further reveal 499 cytotoxicity-related molecules, 212 of which contain polyethylene glycol, glucose, or benzene-related structures. Photo-induced production of hydroxyl and alkyl radicals play important roles in CD degradation as affected by temperature, pH, light intensity and wavelength. Commercial CDs show similar photodegraded products and cytotoxicity profiles, demonstrating that photodegradation-induced cytotoxicity is likely common to CDs regardless of their chemical composition. Our results highlight the importance of light in cytocompatibility studies of CDs.


Asunto(s)
Carbono/toxicidad , Citotoxinas/toxicidad , Puntos Cuánticos/toxicidad , Derivados del Benceno/química , Derivados del Benceno/toxicidad , Carbono/química , Carbono/efectos de la radiación , Supervivencia Celular/efectos de los fármacos , Citotoxinas/química , Glucosa/química , Glucosa/toxicidad , Células HEK293 , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Radical Hidroxilo/química , Radical Hidroxilo/toxicidad , Cinética , Luz , Fotólisis , Polietilenglicoles/química , Polietilenglicoles/toxicidad , Puntos Cuánticos/química , Puntos Cuánticos/efectos de la radiación , Temperatura
11.
Nat Commun ; 12(1): 830, 2021 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-33547297

RESUMEN

In marine and freshwater oxygen-deficient zones, the remineralization of sinking organic matter from the photic zone is central to driving nitrogen loss. Deep blooms of photosynthetic bacteria, which form the suboxic/anoxic chlorophyll maximum (ACM), widespread in aquatic ecosystems, may also contribute to the local input of organic matter. Yet, the influence of the ACM on nitrogen and carbon cycling remains poorly understood. Using a suite of stable isotope tracer experiments, we examined the transformation of nitrogen and carbon under an ACM (comprising of Chlorobiaceae and Synechococcales) and a non-ACM scenario in the anoxic zone of Lake Tanganyika. We find that the ACM hosts a tight coupling of photo/litho-autotrophic and heterotrophic processes. In particular, the ACM was a hotspot of organic matter remineralization that controlled an important supply of ammonium driving a nitrification-anammox coupling, and thereby played a key role in regulating nitrogen loss in the oxygen-deficient zone.


Asunto(s)
Ciclo del Carbono/fisiología , Carbono/química , Chlorobi/metabolismo , Ciclo del Nitrógeno/fisiología , Nitrógeno/química , Synechococcus/metabolismo , Compuestos de Amonio/química , Compuestos de Amonio/metabolismo , Anaerobiosis/fisiología , Procesos Autotróficos , Carbono/metabolismo , Chlorobi/química , Clorofila/química , Clorofila/metabolismo , República Democrática del Congo , Ecosistema , Marcaje Isotópico , Lagos/química , Lagos/microbiología , Nitrificación/fisiología , Nitrógeno/metabolismo , Oxidación-Reducción , Synechococcus/química , Tanzanía
12.
J Chromatogr A ; 1641: 461990, 2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33640806

RESUMEN

This study demonstrates a novel application of nitrogen-doped carbon dots (NCDs) to enable the separation of different lengths of single-stranded DNA (ssDNA) by eletrokinetic means. Carbon dots have recently found widespread application in the fields of sensing, diagnostics, and healthcare due to their biocompatibility and low toxicity. In light of growing interest in the use of ssDNA aptamers over antibodies in the fields of biosensor development and drug delivery, it is important to establish a simple and effective method for aptamer separation. In this study, we employed NCDs as buffer additives in a capillary electrophoresis (CE)-based method, giving rise to the separation of FAM-labeled ssDNA samples ranging from 32 to 100 bases in length, with resolutions ranging from 1.30 - 1.77. In particular, we adopted a capillary transient isotachophoresis (ctITP) system with laser-induced fluorescence (LIF) detection, with both the separation and sample buffers modified by the addition of 30 µg/mL NCDs. These nanomaterials were prepared by a simple hydrothermal method from a mixture of citric acid and ethylenediamine. The NCDs themselves are highly fluorescent and photostable. As components in the background electrolyte, they did not interfere with the fluorescence emission of the FAM-labeled DNA samples. Under the conditions employed, no separation could be achieved in the absence of the NCDs nor with undoped CDs. The results show that NCDs function as buffer additives capable of enhancing electrokinetic-based separations of ssDNA, and hence, provide a new application for these carbon nanomaterials.


Asunto(s)
Carbono/química , ADN de Cadena Simple/aislamiento & purificación , Electroforesis Capilar/métodos , Isotacoforesis/métodos , Rayos Láser , Nitrógeno/química , Electroósmosis , Fluorescencia
13.
Food Chem ; 345: 128812, 2021 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-33601655

RESUMEN

Due to complex matrixes and specific reagent deficiency, the rapid detection of histamine is still a challenge to date. Based on the high peroxidase-like activity of iron-cobalt co-doped carbon dots, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was established for histamine detection using the mimic enzyme labeled with histamine antibody (His-Ab). Through the competitive binding of the labeled His-Ab to solid-phase and sample antigens, histamine content was detected with a linear range of 2.5-150 µg mL-1. The detection limit based on 3σ/K was 0.50 mg kg-1, which was much lower than those of commercial His-kit and HPLC methods. The ic-ELISA method was applied to histamine detection in fish samples with the recovery of (103.4 ± 0.5)%, which was in accord with those of commercial His-kit and HPLC methods. The results indicated that the established ic-ELISA method was suitable for rapid detection of histamine in fish samples with high accuracy, sensitivity and stability.


Asunto(s)
Peces/metabolismo , Histamina/análisis , Puntos Cuánticos/química , Animales , Anticuerpos/química , Anticuerpos/inmunología , Carbono/química , Cobalto/química , Ensayo de Inmunoadsorción Enzimática , Histamina/inmunología , Hierro/química , Límite de Detección , Reproducibilidad de los Resultados , Alimentos Marinos/análisis
14.
Food Chem ; 350: 129197, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33618098

RESUMEN

A fluorescent assay for the selective analysis of tartrazine was developed. Tartrazine is a health-threatening food additive commonly used as fake saffron. An optical nanosensor was fabricated based on molecular imprinting technique in which carbon dots (CDs) as fluorophores and tartrazine as a template molecule were embedded in molecularly imprinted polymer (MIP) matrix. The synthesized CDs embedded in MIP (CDs-MIP) was characterized by various methods. The fluorescence intensity of (CDs-MIP) was selectively quenched in the presence of tartrazine in comparison with other similar food color additives. The correlation between the quenching of CD-MIP and the concentration of tartrazine was used as an optical sensing for rapid detection of tartrazine in the range of 3.3-20.0 nM (1.8-10.7 µg L-1) with detection limit of 1.3 nM (0.70 µg L-1). Eventually, the designed nanosensor was successfully applied for tartrazine detection in foodstuffs such as fake saffron, saffron tea and saffron ice cream samples.


Asunto(s)
Crocus/química , Contaminación de Alimentos/análisis , Límite de Detección , Nanotecnología/instrumentación , Dispositivos Ópticos , Tartrazina/análisis , Carbono/química , Colorantes Fluorescentes/química , Impresión Molecular , Control de Calidad
15.
Food Chem ; 347: 129069, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33493839

RESUMEN

The growth and metabolism of Alicyclobacillus acidoterrestris can lead to the spoilage of commercial fruit juice. Existing methods have some drawbacks such as complex sample pretreatment, skilled technician requirement, reduced sensitivity and specificity. Herein, a novel fluorescence immunoassay was developed using a monoclonal antibody (mAb) against A. acidoterrestris as the sensing element and carbon dots (CDs) as the signal response unit. The CDs can be quenched via fluorescence resonance energy transfer (FRET) by the oxidization product of p-phenylenediamine (PPD), a chromogenic substrate of horseradish peroxidase (HRP). This approach showed enhanced accuracy and sensitivity with relatively low limit of detection (LOD) of 6.16 × 102 CFU mL-1. Moreover, apple juice contaminated with 1 CFU mL-1 of A. acidoterrestris can be identified after 24 h enrichment. This fluorescence immunoassay could serve as a powerful tool for laboratory identification and on-site inspection of A. acidoterrestris, reducing the adverse effect on the quality of fruit juice.


Asunto(s)
Alicyclobacillus/aislamiento & purificación , Anticuerpos Monoclonales/inmunología , Jugos de Frutas y Vegetales/microbiología , Inmunoensayo/métodos , Malus/microbiología , Puntos Cuánticos/química , Alicyclobacillus/inmunología , Anticuerpos Monoclonales/química , Carbono/química , Transferencia Resonante de Energía de Fluorescencia , Microbiología de Alimentos , Límite de Detección , Malus/metabolismo
16.
ACS Appl Mater Interfaces ; 13(1): 1277-1287, 2021 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-33393300

RESUMEN

Selective discrimination and lasting tracking of live bacteria are primary steps for microbiology research and treatment of bacterial infection. However, conventional detection methods, such as the gold standard of Gram staining, are being challenged under actual test conditions. Herein, we provided a novel method, namely, three excitation peaks and single-color emission carbon quantum dots (T-SCQDs) for the rapid (5 min) peptidoglycan-targeting discrimination of Gram-positive bacteria and lasting tracking (24 h) through one-step staining. Bacterial viability testing indicates that T-SCQDs can achieve nondestructive identification of Gram-positive bacteria within 50-500 µg mL-1. Interestingly, the fluorescence imaging system suggests that T-SCQDs can also selectively distinguish the type of colonies based on fluorescence intensity. Furthermore, T-SCQDs were successfully used to visually distinguish Gram-positive bacteria from the microbial environment of A549 cells by confocal fluorescence microscopy. These properties endow T-SCQDs with excellent functions for the diagnosis of infection and other biological applications.


Asunto(s)
Colorantes Fluorescentes/química , Peptidoglicano/metabolismo , Puntos Cuánticos/química , Staphylococcus aureus/aislamiento & purificación , Células A549 , Carbono/química , Carbono/metabolismo , Carbono/toxicidad , Colorantes Fluorescentes/metabolismo , Colorantes Fluorescentes/toxicidad , Humanos , Microscopía Confocal , Microscopía Fluorescente , Puntos Cuánticos/metabolismo , Puntos Cuánticos/toxicidad
17.
ACS Appl Mater Interfaces ; 13(4): 5877-5886, 2021 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-33482691

RESUMEN

Chiral carbon dots (CDs) integrated the advantages of achiral CDs and the unique chiral property, which expand the prospect of the biological applications of CDs. However, the structure control and the origin of chirality for chiral CDs remain unclear. Herein, chiral CDs were obtained by thermal polymerization of chiral amino acids and citric acid, and their handedness of chirality could be controlled by adjusting the reaction temperature, which leads to different kinds of surface modifications. With aliphatic amino acids as a chiral source, all of the CDs that reacted at different temperatures (90-200 °C) have the same handedness of the chiral source. But with aromatic amino acids as a chiral source, CDs with maintained or inversed handedness compared with the chiral source could be obtained by adjusting the reaction temperature. Below a temperature of 120 °C, the chiral source was modified with CDs by esterification and transferred the handedness of chirality; at high temperatures (above 150 °C), which mainly connected by amidation accompanying with the formation of rigid structure generated by the π conjugation between the aromatic nucleus of chiral source and the carbon core of CDs, caused the inversing of the chiral signal. Further, we investigated the chiral effects of CDs on the glucose oxidase activity for a highly sensitive electrochemical biosensor.


Asunto(s)
Aminoácidos/química , Técnicas Biosensibles/métodos , Glucosa Oxidasa/química , Glucosa/análisis , Puntos Cuánticos/química , Carbono/química , Ácido Cítrico/química , Estabilidad de Enzimas , Esterificación , Modelos Moleculares , Polimerizacion , Puntos Cuánticos/ultraestructura , Estereoisomerismo , Propiedades de Superficie
18.
Food Chem ; 346: 128901, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33450645

RESUMEN

An electrochemical deposition method was used to fabricate a gold nanoflower (AuNF) and carbon nanoparticle (CNP) modified carbon paper (CP) sensor (AuNFs-CNPs/CP) for the low-cost detection of 5-methyltetrahydrofolate (5-mTHF) in egg yolk. AuNF morphology and structures were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), revealing nanoflower sizes in the 50 to 200 nm range. AuNFs formed on the sensor were in the Au0. We evaluated 5-mTHF assay performance using cyclic voltammetry, differential pulse voltammetry and chronoamperometry. The AuNFs-CNPs/CP sensor detected 5-mTHF concentrations in the ranges from 1 to 5 mg L-1 and 1-20 µg L-1, with an excellent limit of detection of 1 µg L-1 and good selectivity toward 5-mTHF, when compared to other potentially interfering molecules in samples. The AuNFs-CNPs/CP sensor was also used to detect 5-mTHF in folate-rich, and was found to be twice than that of ordinary egg yolk.


Asunto(s)
Yema de Huevo/química , Técnicas Electroquímicas/métodos , Papel , Tetrahidrofolatos/análisis , Carbono/química , Yema de Huevo/metabolismo , Técnicas Electroquímicas/instrumentación , Electrodos , Oro/química , Límite de Detección , Nanoestructuras/química , Reproducibilidad de los Resultados
19.
Ecotoxicol Environ Saf ; 211: 111934, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33472109

RESUMEN

In the present work, we reported a one pot simple colloidal-gel synthesis of molybdenum bismuth vanadate (MoBiVO4). The charge transfer property of MoBiVO4 was improved by developing a composite with graphene oxide (GO) through sonochemical technique. The optical and morphological analysis revealed that successful formation of GO-MoBiVO4 composite without any other filth. As prepared composite was used to modify the superficial surface of glassy carbon electrode (GO-MoBiVO4/GCE) and applied for the selective detection of environmental pollutant 2, 4, 6 trichrlorophenol (TCP). The electron channeling capability of GO with molybdenum bismuth vanadate possessed a superior electrochemical response in cyclic voltammetry (CV), whereas bare GCE and other modified electrodes provided an inferior response with lower current response. The differential pulse voltammetry (DPV) response of TCP at GO-MoBiVO4/GCE outcomes with low level detection of 0.4 nM and higher sensitivity of 2.49 µA µM-1 cm-2 with wider linear response 0.199-17.83 µM. Furthermore, the proposed sensor applied in practicability analysis and the results indicates GO-MoBiVO4/GCE prominent towards electrochemical detection of TCP.


Asunto(s)
Bismuto/química , Clorofenoles/análisis , Monitoreo del Ambiente/métodos , Contaminantes Ambientales/análisis , Grafito/química , Molibdeno/química , Vanadatos/química , Carbono/química , Clorofenoles/química , Técnicas Electroquímicas/métodos , Electrodos , Contaminantes Ambientales/química
20.
Nat Commun ; 12(1): 312, 2021 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-33436622

RESUMEN

The transmembrane P-glycoprotein (P-gp) pumps that efflux drugs are a major mechanism of cancer drug resistance. They are also important in protecting normal tissue cells from poisonous xenobiotics and endogenous metabolites. Here, we report a fucoidan-decorated silica-carbon nano-onion (FSCNO) hybrid nanoparticle that targets tumor vasculature to specifically release P-gp inhibitor and anticancer drug into tumor cells. The tumor vasculature targeting capability of the nanoparticle is demonstrated using multiple models. Moreover, we reveal the superior light absorption property of nano-onion in the near infrared region (NIR), which enables triggered drug release from the nanoparticle at a low NIR power. The released inhibitor selectively binds to P-gp pumps and disables their function, which improves the bioavailability of anticancer drug inside the cells. Furthermore, free P-gp inhibitor significantly increases the systemic toxicity of a chemotherapy drug, which can be resolved by delivering them with FSCNO nanoparticles in combination with a short low-power NIR laser irradiation.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Carbono/química , Sistemas de Liberación de Medicamentos , Resistencia a Antineoplásicos , Nanopartículas/química , Neoplasias/tratamiento farmacológico , Selectina-P/metabolismo , Animales , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Doxorrubicina/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Ratones , Microfluídica , Nanopartículas/ultraestructura , Neoplasias/irrigación sanguínea , Polisacáridos/química , Dióxido de Silicio/química
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