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1.
Nat Commun ; 12(1): 2002, 2021 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-33790299

RESUMEN

Helicobacter pylori infection is a major etiological factor in gastric diseases. However, clinical antibiotic therapy for H. pylori is limited by continuously decreased therapeutic efficacy and side effects to symbiotic bacteria. Herein, we develop an in vivo activatable pH-responsive graphitic nanozyme, PtCo@Graphene (PtCo@G), for selective treatment of H. pylori. Such nanozymes can resist gastric acid corrosion, exhibit oxidase-like activity to stably generate reactive oxygen species only in acidic gastric milieu and demonstrate superior selective bactericidal property. C18-PEGn-Benzeneboronic acid molecules are modified on PtCo@G, improving its targeting capability. Under acidic gastric pH, graphitic nanozymes show notable bactericidal activity toward H. pylori, while no bacterial killing is observed under intestinal conditions. In mouse model, high antibacterial capability toward H. pylori and negligible side effects toward normal tissues and symbiotic bacteria are achieved. Graphitic nanozyme displays the desired enzyme-like activities at corresponding physiological sites and may address critical issues in clinical treatment of H. pylori infections.


Asunto(s)
Mucosa Gástrica/enzimología , Grafito/química , Infecciones por Helicobacter/enzimología , Helicobacter pylori/metabolismo , Oxidorreductasas/metabolismo , Animales , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/uso terapéutico , Ácido Gástrico/metabolismo , Mucosa Gástrica/metabolismo , Mucosa Gástrica/microbiología , Infecciones por Helicobacter/microbiología , Infecciones por Helicobacter/terapia , Helicobacter pylori/efectos de los fármacos , Helicobacter pylori/fisiología , Humanos , Concentración de Iones de Hidrógeno , Ratones , Oxidorreductasas/química , Oxidorreductasas/uso terapéutico , Especies Reactivas de Oxígeno/metabolismo
2.
Int J Mol Sci ; 22(6)2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33804239

RESUMEN

Cancer is one of the deadliest diseases in human history with extremely poor prognosis. Although many traditional therapeutic modalities-such as surgery, chemotherapy, and radiation therapy-have proved to be successful in inhibiting the growth of tumor cells, their side effects may vastly limited the actual benefits and patient acceptance. In this context, a nanomedicine approach for cancer therapy using functionalized nanomaterial has been gaining ground recently. Considering the ability to carry various anticancer drugs and to act as a photothermal agent, the use of carbon-based nanomaterials for cancer therapy has advanced rapidly. Within those nanomaterials, reduced graphene oxide (rGO), a graphene family 2D carbon nanomaterial, emerged as a good candidate for cancer photothermal therapy due to its excellent photothermal conversion in the near infrared range, large specific surface area for drug loading, as well as functional groups for functionalization with molecules such as photosensitizers, siRNA, ligands, etc. By unique design, multifunctional nanosystems could be designed based on rGO, which are endowed with promising temperature/pH-dependent drug/gene delivery abilities for multimodal cancer therapy. This could be further augmented by additional advantages offered by functionalized rGO, such as high biocompatibility, targeted delivery, and enhanced photothermal effects. Herewith, we first provide an overview of the most effective reducing agents for rGO synthesis via chemical reduction. This was followed by in-depth review of application of functionalized rGO in different cancer treatment modalities such as chemotherapy, photothermal therapy and/or photodynamic therapy, gene therapy, chemotherapy/phototherapy, and photothermal/immunotherapy.


Asunto(s)
Grafito/uso terapéutico , Nanomedicina/tendencias , Nanoestructuras/uso terapéutico , Neoplasias/terapia , Antineoplásicos/química , Antineoplásicos/uso terapéutico , Doxorrubicina/química , Doxorrubicina/uso terapéutico , Portadores de Fármacos/química , Portadores de Fármacos/uso terapéutico , Grafito/química , Humanos , Nanoestructuras/química , Neoplasias/patología , Fotoquimioterapia/métodos , Fototerapia/métodos
3.
Int J Mol Sci ; 22(6)2021 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-33805752

RESUMEN

Graphene coating on the cobalt-chromium alloy was optimized and successfully carried out by a cold-wall chemical vapor deposition (CW-CVD) method. A uniform layer of graphene for a large area of the Co-Cr alloy (discs of 10 mm diameter) was confirmed by Raman mapping coated area and analyzing specific G and 2D bands; in particular, the intensity ratio and the number of layers were calculated. The effect of the CW-CVD process on the microstructure and the morphology of the Co-Cr surface was investigated by scanning X-ray photoelectron microscope (SPEM), atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Nanoindentation and scratch tests were performed to determine mechanical properties of Co-Cr disks. The results of microbiological tests indicate that the studied Co-Cr alloys covered with a graphene layer did not show a pro-coagulant effect. The obtained results confirm the possibility of using the developed coating method in medical applications, in particular in the field of cardiovascular diseases.


Asunto(s)
Aleaciones de Cromo/química , Materiales Biocompatibles Revestidos/química , Grafito/química , Animales , Factores de Coagulación Sanguínea/metabolismo , Plaquetas/citología , Plaquetas/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Aleaciones de Cromo/farmacología , Materiales Biocompatibles Revestidos/farmacología , Eritrocitos/efectos de los fármacos , Humanos , Ensayo de Materiales/métodos , Ratones , Células 3T3 NIH , Tiempo de Tromboplastina Parcial , Activación Plaquetaria/efectos de los fármacos , Cultivo Primario de Células , Propiedades de Superficie , Volatilización
4.
Int J Nanomedicine ; 16: 2647-2665, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33854313

RESUMEN

Graphene is a new type of carbon nanomaterial discovered after fullerene and carbon nanotube. Due to the excellent biological properties such as biocompatibility, cell proliferation stimulating, and antibacterial properties, graphene and its derivatives have become emerging candidates for the development of novel cutaneous wound dressings and composite scaffolds. On the other hand, pre-clinical research on exosomes derived from mesenchymal stem cells (MSC-Exos) has been intensified for cell-free treatment in wound healing and cutaneous regeneration, via ameliorating the damaged microenvironment of the wound site. Here, we provide a comprehensive understanding of the latest studies and observations on the various effects of graphene-based nanomaterials (GBNs) and MSC-Exos during the cutaneous wound repair process, as well as the putative mechanisms thereof. In addition, we propose the possible forward directions of GBNs and MSC-Exos applications, expecting to promote the clinical transformation.


Asunto(s)
Exosomas/metabolismo , Grafito/química , Células Madre Mesenquimatosas/metabolismo , Nanoestructuras/química , Piel/patología , Cicatrización de Heridas , Animales , Humanos
5.
J Chromatogr A ; 1645: 462104, 2021 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-33857676

RESUMEN

A novel magnetic graphene oxide nanocomposite modified with polyaniline (Fe3O4@GO-PANI) was synthesized and applied for the magnetic solid-phase extraction of polycyclic aromatic hydrocarbons (PAHs) (i.e. fluorene, phenanthrene and pyrene) and nitrated polycyclic aromatic hydrocarbons (N-PAHs) (i.e. 2-nitrofluorene, 9-nitroanthracene, 1-nitropyrene and 3-nitrofluoranthene) prior to their determination by gas chromatography-mass spectrometry. The prepared nanomaterial was characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform-infrared spectroscopy. The main experimental parameters affecting the extraction and desorption steps of the MSPE procedure were investigated and optimized. Under optimum conditions, coefficients of determination (r2) ranged between 0.9970 and 0.9995, limits of detection (LODs, S/N = 3) ranged between 0.04-0.05 ng mL-1 for PAHs and 0.01-0.11 ng mL-1 for N-PAHs, while the relative standard deviation for intra-day and inter-day repeatability were lower than 10.0% for PAHs and N-PAHs. The method was successfully applied to the analysis of tap, mineral and river water samples. Relative recoveries in spiked water samples ranged between from 91.6 to 114% and from 92.3 to 110% for PAHs and N-PAHs, respectively. The proposed method is simple, rapid, sensitive and the Fe3O4@GO-PANI sorbent can be reused for at least 15 times without significant decrease in extraction recovery.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Extracción en Fase Sólida/métodos , Sonicación/métodos , Contaminantes Químicos del Agua , Compuestos de Anilina/química , Cromatografía de Gases y Espectrometría de Masas , Grafito/química , Imanes , Nanocompuestos/química , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/aislamiento & purificación , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/aislamiento & purificación
6.
Nat Commun ; 12(1): 1755, 2021 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-33741935

RESUMEN

All-electronic interrogation of biofluid flow velocity by electrical nanosensors incorporated in ultra-low-power or self-sustained systems offers the promise of enabling multifarious emerging research and applications. However, existing nano-based electrical flow sensing technologies remain lacking in precision and stability and are typically only applicable to simple aqueous solutions or liquid/gas dual-phase mixtures, making them unsuitable for monitoring low-flow (~micrometer/second) yet important characteristics of continuous biofluids (such as hemorheological behaviors in microcirculation). Here, we show that monolayer-graphene single microelectrodes harvesting charge from continuous aqueous flow provide an effective flow sensing strategy that delivers key performance metrics orders of magnitude higher than other electrical approaches. In particular, over six-months stability and sub-micrometer/second resolution in real-time quantification of whole-blood flows with multiscale amplitude-temporal characteristics are obtained in a microfluidic chip.


Asunto(s)
Grafito/química , Microelectrodos , Técnicas Analíticas Microfluídicas/instrumentación , Técnicas Analíticas Microfluídicas/métodos , Animales , Velocidad del Flujo Sanguíneo , Bovinos , Cobre/química , Dispositivos Laboratorio en un Chip , Fenómenos Físicos , Polimetil Metacrilato/química
7.
J Vis Exp ; (169)2021 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-33749671

RESUMEN

On-surface synthesis has recently been regarded as a promising approach for the generation of new molecular structures. It has been particularly successful in the synthesis of graphene nanoribbons, nanographenes and intrinsically reactive and instable, yet attractive species. It is based on the combination of solution chemistry aimed at preparation of appropriate molecular precursors for further ultra-high vacuum surface assisted transformations. This approach also owes its success to an incredible development of characterization techniques, such as scanning tunneling/atomic force microscopy and related methods, which allow detailed, local characterization at atomic scale. While the surface-assisted synthesis can provide molecular nanostructures with outstanding precision, down to single atoms, it suffers from basing on metallic surfaces and often limited yield. Therefore, the extension of the approach away from metals and the struggle to increase productivity seem to be significant challenges toward wider applications. Herein, we demonstrate the on-surface synthesis approach for generation of non-planar nanographenes, which are synthesized through a combination of solution chemistry and sequential surface-assisted processes, together with the detailed characterization by scanning probe microscopy methods.


Asunto(s)
Grafito/química , Microscopía de Fuerza Atómica/métodos , Nanoestructuras/química , Monóxido de Carbono/química , Oro/química , Grafito/síntesis química , Hidrogenación , Nanoestructuras/ultraestructura , Porosidad , Soluciones , Análisis Espectral , Propiedades de Superficie , Vacio
8.
Int J Nanomedicine ; 16: 1601-1616, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33688181

RESUMEN

Introduction: Cancer is the second leading cause of death globally and is responsible, where about 1 in 6 deaths in the world. Therefore, there is a need to develop effective antitumor agents that are targeted only to the specific site of the tumor to improve the efficiency of cancer diagnosis and treatment and, consequently, limit the unwanted systemic side effects currently obtained by the use of chemotherapeutic agents. In this context, due to its unique physical and chemical properties of graphene oxide (GO), it has attracted interest in biomedicine for cancer therapy. Methods: In this study, we report the in vivo application of nanocomposites based on Graphene Oxide (nc-GO) with surface modified with PEG-folic acid, Rhodamine B and Indocyanine Green. In addition to displaying red fluorescence spectra Rhodamine B as the fluorescent label), in vivo experiments were performed using nc-GO to apply Photodynamic Therapy (PDT) and Photothermal Therapy (PTT) in the treatment of Ehrlich tumors in mice using NIR light (808 nm 1.8 W/cm2). Results: This study based on fluorescence images was performed in the tumor in order to obtain the highest concentration of nc-GO in the tumor as a function of time (time after intraperitoneal injection). The time obtained was used for the efficient treatment of the tumor by PDT/PTT. Discussion: The current study shows an example of successful using nc-GO nanocomposites as a theranostic nanomedicine to perform simultaneously in vivo fluorescence diagnostic as well as combined PDT-PTT effects for cancer treatments.


Asunto(s)
Grafito/química , Fotoquimioterapia , Nanomedicina Teranóstica , Adsorción , Animales , Benzofuranos/química , Carcinoma de Ehrlich/patología , Carcinoma de Ehrlich/terapia , Humanos , Verde de Indocianina/farmacología , Masculino , Ratones , Nanocompuestos/química , Tamaño de la Partícula , Rodaminas/farmacología , Espectrometría de Fluorescencia , Espectrometría Raman , Electricidad Estática , Carga Tumoral
9.
Int J Nanomedicine ; 16: 1901-1911, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33707945

RESUMEN

Purpose: Developing a sensitive SERS-based method to quantitatively detect serum biomarkers (Aß1-42 and P-Tau-181) for the early diagnosis of Alzheimer's disease (AD). Methods: In this study, a novel SERS-based sandwich immunoassay, which consists of tannin-capped silver nanoparticles and magnetic graphene oxide (Fe3O4@GOs), was developed. We firstly applied this method for the detection of protein standards in buffer solution, obtaining the regression equation. Then, its potential value on real serum samples of AD was further explored. Results: The detection linear range of Aß1-42 and P-Tau-181 protein standards were observed to range from 100 pg mL-1 to 10 fg mL-1, 100 pg mL-1 to 1 fg mL-1 respectively. We finally explored clinical application of the proposed method in 63 serum samples. As a result, P-tau-181 differentiated AD from non-AD dementia patients (AUC = 0.770), with a more favored ROC than Aß1-42 (AUC = 0.383). Conclusion: The developed SERS-based immunoassay is successfully applied to the determination of Aß1-42 and P-Tau-181 in human serum specimens, which provides a promising tool for the early diagnosis of AD.


Asunto(s)
Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/diagnóstico , Biomarcadores/sangre , Inmunoensayo/métodos , Sondas Moleculares/química , Plata/química , Espectrometría Raman/métodos , Péptidos beta-Amiloides/sangre , Benzoatos/química , Calibración , Femenino , Grafito/química , Humanos , Límite de Detección , Masculino , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Compuestos de Sulfhidrilo/química , Difracción de Rayos X , Proteínas tau/sangre
10.
J Chromatogr A ; 1643: 462081, 2021 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-33780883

RESUMEN

In the present work, with the focus on an environmentally-friendly approach, some gels were prepared by synthesizing amine-modified lignin, extracted from sugarcane bagasse, and further esterification and subsequent freeze-drying. These lignin-based gels were implemented as extractive phases in an online micro-solid phase extraction (µSPE) setup in conjunction with high performance liquid chromatography (HPLC) with UV detector. The developed method was used for analytical determination of valsartan and losartan in urine samples. To study the effect of the functionalization process, the efficiency of the unmodified lignin and the functionalized lignin were compared both in the absence and the presence of graphene oxide (GO), presumably as a suitable doping agent. Surprisingly, higher extraction efficiency for the functionalized lignin, compared to both unmodified lignin and GO was observed. The amination process for the prepared gel was analyzed and proved by CHNS elemental analysis and Fourier transform infrared (FT-IR) spectroscopy. The morphology of sorbet was investigated via scanning electron microscope (SEM) imaging and a nanoscale cauliflower feature was observed. The method was optimized and subsequently applied to the analysis of the urine samples. Limits of detection (LOD) of 8 and 6 µg L - 1, limits of quantification (LOQ) of 27 and 20 µg L - 1 and linear dynamic range (LDR) of 27-2000 and 20-2000 µg L - 1 with intraday relative standard deviations (RSD%) of 4 and 3% were obtained for valsartan and losartan, respectively. The whole online µSPE-HPLC setup was conveniently used for the analysis of a patient urine sample and a quantity of 352 µg L - 1 of losartan was found. Acceptable relative recoveries (109-108 and 95-94% for valsartan and losartan) revealed the analytical potential of the method for the determination of drugs in complex urine samples.


Asunto(s)
Lignina/química , Losartán/orina , Microextracción en Fase Sólida/métodos , Valsartán/orina , Aminas/química , Celulosa/metabolismo , Cromatografía Líquida de Alta Presión/métodos , Grafito/química , Humanos , Límite de Detección , Losartán/aislamiento & purificación , Reproducibilidad de los Resultados , Espectrofotometría Ultravioleta , Valsartán/aislamiento & purificación
11.
Molecules ; 26(4)2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33672689

RESUMEN

To expand the applications of graphene-based materials to biogas purification, a series of reduced graphene oxide aerogels (rGOAs) were prepared from industrial grade graphene oxide using a simple hydrothermal method. The influences of the hydrothermal preparation temperature on the textural properties, hydrophobicity and physisorption behavior of the rGOAs were investigated using a range of physical and spectroscopic techniques. The results showed that the rGOAs had a macro-porous three-dimensional network structure. Raising the hydrothermal treatment temperature reduced the number of oxygen-containing groups, whereas the specific surface area (SBET), micropore volume (Vmicro) and water contact angle values of the rGOAs all increased. The dynamic adsorption properties of the rGOAs towards hexamethyldisiloxane (L2) increased with increasing hydrothermal treatment temperature and the breakthrough adsorption capacity showed a significant linear association with SBET, Vmicro and contact angle. There was a significant negative association between the breakthrough time and inlet concentration of L2, and the relationship could be reliably predicted with a simple empirical formula. L2 adsorption also increased with decreasing bed temperature. Saturated rGOAs were readily regenerated by a brief heat-treatment at 100 °C. This study has demonstrated the potential of novel rGOA for applications using adsorbents to remove siloxanes from biogas.


Asunto(s)
Grafito/química , Siloxanos/química , Adsorción , Geles/química , Interacciones Hidrofóbicas e Hidrofílicas , Oxidación-Reducción , Tamaño de la Partícula , Propiedades de Superficie
12.
Food Chem ; 352: 129430, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33691211

RESUMEN

The present work reports the development of a novel electrochemical sensor for the selective detection of fructose. The sensor was developed through electropolymerization of a molecularly imprinted polymer film on a reduced graphene oxide modified electrode. The modified electrode was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy, atomic force microscopy and RAMAN spectroscopy. Through the application of the modified electrode, the recognition of fructose molecules occurred in a concentration range of 1.0 × 10-14 to 1.0 × 10-11 mol L-1, under a Langmuir adsorption isothermal model. The sensitivity and limits of detection and quantification obtained for the sensor were 9.9 × 107 A L mol-1, 3.2 × 10-15 mol L-1 and 1.1 × 10-14 mol L-1, respectively. The analytical method used for the detection of fructose presented good reproducibility, stability and accuracy, and was successfully applied for the quantification of this sugar in orange, apple and grape juices.


Asunto(s)
Electroquímica/instrumentación , Análisis de los Alimentos/instrumentación , Fructosa/análisis , Jugos de Frutas y Vegetales/análisis , Grafito/química , /química , Electrodos , Fructosa/química , Límite de Detección , Reproducibilidad de los Resultados
13.
Carbohydr Polym ; 260: 117835, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712172

RESUMEN

Bacterial breeding is the main cause of food perishability, which is harmful to human health. Silver nanoparticles (AgNPs) are one of the most widely used antimicrobial agents, but they are easy to release and cause cumulative toxicity. In this work, with corn stalk as green reductant and GO as template, a simple electrostatic self-assembled sandwich-like chitosan (CS) wrapped rGO@AgNPs nanocomposite film (CS/rGO@AgNPs) was synthesized to achieve stabilizing and controlled-release of AgNPs. The results showed that the the CS/rGO@AgNPs film continued releasing AgNPs for up to 14 days, and the final release amount of silver nanoparticles was only about 1.9 %. More importantly, the nanocomposite film showed durable antibacterial effect and good antibacterial activity against E. coli and S. aureus, and they showed no toxicity to cells. Hence, the nanocomposite film has potential application as an effective and safe packaging material to prolong the shelf life of food products.


Asunto(s)
Antibacterianos/química , Quitosano/química , Grafito/química , Nanopartículas del Metal/química , Nanocompuestos/química , Antibacterianos/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Escherichia coli/efectos de los fármacos , Humanos , Nanocompuestos/toxicidad , Plata/química , Solubilidad , Staphylococcus aureus/efectos de los fármacos , Resistencia a la Tracción
14.
Food Chem ; 352: 129187, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33652196

RESUMEN

A novel covalent organic framework material (3DGA@COFs), for use as a solid-phase dispersion sorbent, has been synthesized for extracting organophosphorus pesticides (OPs) from vegetables. The prepared 3DGA@COFs material exhibited many advantageous features, including a large specific surface area (127.95 m2/g) and high pore volume (0.0344 cm3/g), which made it an ideal sorbent for sample pretreatment. The experimental conditions affecting extraction performance (adsorbent type, adsorbent amount, reaction time, pH, ionic concentration, and eluent) were optimized systematically. The extracted analytes were detected by HPLC-MS/MS. Under optimized conditions, the proposed method exhibited a wide linear range (0.5-100 µg/L) and low limits of detection (0.01-0.14 µg/L). The recoveries (75.40%-102.13%) satisfied the requirements for a precise detection method. The proposed method was successfully used for determining malathion, triazophos, quinalphos in lettuce, tomato and cucumber samples, thus indicating the potential of using 3DGA@COFs materials for pretreating vegetable samples.


Asunto(s)
Grafito/química , Hidrogeles/química , Estructuras Metalorgánicas/síntesis química , Compuestos Organofosforados/aislamiento & purificación , Plaguicidas/aislamiento & purificación , Extracción en Fase Sólida/métodos , Verduras/química , Adsorción , Técnicas de Química Sintética , Contaminación de Alimentos/análisis , Concentración de Iones de Hidrógeno , Límite de Detección , Estructuras Metalorgánicas/química , Compuestos Organofosforados/análisis , Compuestos Organofosforados/química , Plaguicidas/análisis , Plaguicidas/química , Factores de Tiempo
15.
Food Chem ; 352: 129330, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33657486

RESUMEN

Pregnancy test strips are one of the most mature and widely used commercial lateral flow devices used to determine pregnancy. Being a simple and rapid detection method, human chorionic gonadotropin (hCG) was used with different aptamers (hCG-apt) as probes for the detection of metal ions, small organic molecules, and proteins. Quantitative detection of target analytes was achieved using a smartphone app and a portable device developed in our laboratory. The results showed detection ranges of 1 nM-1 µM, 0.1 nM-10 µM and 32 nM-500 nM for Pb2+, chloramphenicol, and ß-lactoglobulin, respectively, and the corresponding visual detection limits in dairy products were 5 nM, 1 nM and 50 nM, respectively. Based on these results, rapid detection of multiple analytes can be realized through aptamer modification, thereby broadening the application range of commercial lateral flow devices for analysis of food chemistry.


Asunto(s)
Aptámeros de Nucleótidos/metabolismo , Productos Lácteos/análisis , Compuestos Férricos/química , Análisis de los Alimentos/instrumentación , Grafito/química , Pruebas de Embarazo/instrumentación , Teléfono Inteligente , Animales , Femenino , Oro/química , Humanos , Límite de Detección , Embarazo
16.
Adv Mater ; 33(16): e2100218, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33683745

RESUMEN

From typical electrical appliances to thriving intelligent robots, the exchange of information between humans and machines has mainly relied on the contact sensor medium. However, this kind of contact interaction can cause severe problems, such as inevitable mechanical wear and cross-infection of bacteria or viruses between the users, especially during the COVID-19 pandemic. Therefore, revolutionary noncontact human-machine interaction (HMI) is highly desired in remote online detection and noncontact control systems. In this study, a flexible high-sensitivity humidity sensor and array are presented, fabricated by anchoring multilayer graphene (MG) into electrospun polyamide (PA) 66. The sensor works in noncontact mode for asthma detection, via monitoring the respiration rate in real time, and remote alarm systems and provides touchless interfaces in medicine delivery for bedridden patients. The physical structure of the large specific surface area and the chemical structure of the abundant water-absorbing functional groups of the PA66 nanofiber networks contribute to the high performance synergistically. This work can lead to a new era of noncontact HMI without the risk of contagiousness and provide a general and effective strategy for the development of smart electronics that require noncontact interaction.


Asunto(s)
Técnicas Biosensibles/métodos , Electrónica , Asma/diagnóstico , Materiales Biocompatibles/química , Técnicas Biosensibles/instrumentación , Electrodos , Grafito/química , Humanos , Humedad , Internet de las Cosas , Aplicaciones Móviles , Nanofibras/química , Frecuencia Respiratoria , Dispositivos Electrónicos Vestibles
17.
Food Chem ; 352: 129368, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33667921

RESUMEN

A high-performance voltammetric methodology was developed to achieve ultra-sensitive detection of riboflavin, employing an electrode modified by graphene oxide-covered hollow MnO2 spheres nanocomposite with high catalytic activity, large surface area, and hierarchical layered structure. Under the optimal conditions, the current responses of the oxidation peak located at -0.39 V showed a good linear relationship versus the concentration of riboflavin in the range of 1.0 nM-4.0 µM in acetate buffer (pH 5.4). The limit of detection was determined as 0.26 nM. Moreover, the proposed electrode exhibited high reproducibility (relative standard deviation of 1.7%, n = 10) and excellent stability (97.6% sensitivity within two months), which has been successfully applied to the quantification of riboflavin in complicated food matrices, with results in good accordance with those obtained by chromatography as a reference method, indicating it is an effective sensing platform for ultra-sensitive determination of riboflavin in practical applications.


Asunto(s)
Electroquímica/instrumentación , Grafito/química , Compuestos de Manganeso/química , Óxidos/química , Riboflavina/análisis , Catálisis , Electrodos , Análisis de los Alimentos , Límite de Detección , Oxidación-Reducción , Reproducibilidad de los Resultados
18.
Small ; 17(11): e2007091, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33533178

RESUMEN

Search of new strategies for the inhibition of respiratory viruses is one of the urgent health challenges worldwide, as most of the current therapeutic agents and treatments are inefficient. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic and has taken lives of approximately two million people to date. Even though various vaccines are currently under development, virus, and especially its spike glycoprotein can mutate, which highlights a need for a broad-spectrum inhibitor. In this work, inhibition of SARS-CoV-2 by graphene platforms with precise dual sulfate/alkyl functionalities is investigated. A series of graphene derivatives with different lengths of aliphatic chains is synthesized and is investigated for their ability to inhibit SARS-CoV-2 and feline coronavirus. Graphene derivatives with long alkyl chains (>C9) inhibit coronavirus replication by virtue of disrupting viral envelope. The ability of these graphene platforms to rupture viruses is visualized by atomic force microscopy and cryogenic electron microscopy. A large concentration window (10 to 100-fold) where graphene platforms display strongly antiviral activity against native SARS-CoV-2 without significant toxicity against human cells is found. In this concentration range, the synthesized graphene platforms inhibit the infection of enveloped viruses efficiently, opening new therapeutic and metaphylactic avenues against SARS-CoV-2.


Asunto(s)
Grafito/química , /química , Antivirales/farmacología , /virología , Microscopía por Crioelectrón , Humanos , Microscopía de Fuerza Atómica , Pandemias , /efectos de los fármacos
19.
Food Chem ; 351: 129252, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33626469

RESUMEN

Herein, an innovative enzyme free electrochemiluminescence chlorpyrifos sensor was reported based on the incorporation of ternary nanocomposite (ruthenium nanobeads/silver nanoparticles/graphene oxide) on the surface of glassy carbon electrode. The silver nanoparticles as a robust signal enhancing agent were well deposited on the modified graphene oxide/glassy carbon electrode and exhibited supreme electrocatalytic proficiency. Then, Ru(bipy)32+ species in bead-like nanoparticles were uniformly anchored on the surface of the modified electrode with the help of chitosan, as a good crosslinking agent. Boron nitride quantum dots as a new coreactant species showed the excellent proficiency for signal enhancement of the fabricated electrode. The fabricated electrode was successfully used as an ultra-sensitive sensor for trace analysis of chlorpyrifos by ECL technique. The wide linear range and the low detection limit were obtained from 5.0 × 10-15 to 4.2 × 10-9 M and 6.5 × 10-16 M, respectively.


Asunto(s)
Cloropirifos/análisis , Técnicas Electroquímicas/métodos , Mediciones Luminiscentes/métodos , Nanocompuestos/química , Compuestos de Boro/química , Catálisis , Técnicas Electroquímicas/instrumentación , Electrodos , Grafito/química , Límite de Detección , Mediciones Luminiscentes/instrumentación , Nanopartículas del Metal/química , Puntos Cuánticos/química , Rutenio/química , Plata/química
20.
Adv Mater ; 33(10): e2007847, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33538037

RESUMEN

The graphene revolution, which has taken place during the last 15 years, has represented a paradigm shift for science. The extraordinary properties possessed by this unique material have paved the road to a number of applications in materials science, optoelectronics, energy, and sensing. Graphene-related materials (GRMs) are now produced in large scale and have found niche applications also in the biomedical technologies, defining new standards for drug delivery and biosensing. Such advances position GRMs as novel tools to fight against the current COVID-19 and future pandemics. In this regard, GRMs can play a major role in sensing, as an active component in antiviral surfaces or in virucidal formulations. Herein, the most promising strategies reported in the literature on the use of GRM-based materials against the COVID-19 pandemic and other types of viruses are showcased, with a strong focus on the impact of functionalization, deposition techniques, and integration into devices and surface coatings.


Asunto(s)
/diagnóstico , Grafito/química , Nanoestructuras/química , Anticuerpos Inmovilizados/química , Anticuerpos Inmovilizados/inmunología , Antivirales/química , Antivirales/farmacología , Técnicas Biosensibles/métodos , /virología , Técnicas Electroquímicas , Electrodos , Humanos , Límite de Detección , Nanoestructuras/toxicidad , /aislamiento & purificación , Propiedades de Superficie , Proteínas Virales/análisis , Proteínas Virales/inmunología
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