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1.
Environ Res ; 261: 119710, 2024 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-39102938

RESUMEN

Zeolitic Imidazolate (metal organic) Frameworks (ZIFs) and Prussian Blue Analogues (PBAs) are promising materials in electrochemical sensing due to their unique properties. In this study, a composite material comprising NiFe-PBA and ZIF-67 was synthesized and made to form a uniform layer onto a glassy carbon electrode (GCE) to enhance electrochemical performance for furazolidone (FZD) detection. The synthesized NiFe-PBA/ZIF-67 composite exhibited excellent sensitivity, selectivity, and stability towards FZD detection, with a low limit of detection (LOD). The electrochemical behaviour of FZD on the NiFe-PBA/ZIF-67/GCE electrode was investigated, revealing a diffusion-controlled process. Differential pulse voltammetry (DPV) analysis demonstrated the synergetic effect of the PBA/MOF core-shell structure in enhancing FZD electro-reduction. The sensor exhibited exceptional LOD of 0.007 µM. Selectivity studies confirmed the sensor's ability to distinguish FZD from potential interferents. Extensive evaluations demonstrated the sensor's reproducibility, repeatability, and long-term stability, affirming its practical utility. Real sample analysis further validated the sensor's excellent analytical capabilities in diverse matrices.

2.
Chemosphere ; 318: 137948, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36716937

RESUMEN

This study demonstrates a hydrothermal method to prepare perovskite-type potassium niobate (KNbO3) through deep eutectic solvent (DES), which is further used as an electrode material for the determination of bisphenol A (BPA). The as-synthesized KNbO3 was systematically characterized by different microscopic and spectroscopic techniques. The KNbO3-modified electrode demonstrates excellent electrocatalytic activity for BPA compared to the pristine electrode. The enhanced performance of the proposed sensor is attributed to the numerous active sites, large electrochemical surface area, high electrical conductivity, and rapid electron transfer. The fabricated sensor shows a wide detection range (0.01-84.3 µM), a low limit of detection (0.003 µM), a high sensitivity (0.51 µA µM-1 cm-2), and good anti-interference abilities towards the BPA detection by linear sweep voltammetry method. Besides, it was successfully applied to determining BPA in food samples, demonstrating good practicability. This design paves a new way to fabricate efficient electrode material for various electrochemical applications using a DES medium.


Asunto(s)
Disolventes Eutécticos Profundos , Técnicas Electroquímicas , Electrodos , Técnicas Electroquímicas/métodos
3.
Food Chem ; 361: 130162, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34051600

RESUMEN

Fabrication of temperature-influenced nanoparticles over the superficial region of glassy carbon electrode (GCE) stimulates the electrocatalytic activity owing to their morphology, defective sites, and higher active surface area, etc. In this regard, we have fabricated annealed magnesium stannate nanoparticles (Mg2SnO4 NPs) on GCE for nanomolar level detection of hazardous flavoring and pharmaceutical compound Rutin (RT). To analyze the impact of temperature, we have compared annealed Mg2SnO4 NPs with unannealed magnesium stannate hydrate (MgSnO3·3H2O) particles. The physicochemical properties of synthesized materials were characterized with different microscopic and spectroscopic techniques. From these studies, annealed Mg2SnO4 NPs formed purely without any flith and existence of water molecules as compared to unannealed MgSnO3·3H2O. Moreover as fabricated, Mg2SnO4 NPs/GCE outcomes with higher redox behavior compared to other electrodes in presence of RT at optimized working buffer (pH = 7.0). Interestingly, the electrode successfully established a dual wider linear response (0.062-34.8 & 34.8-346.8 µM) with a nanomolar detection limit (1 nM) and higher sensitivity. The practicability analysis of the proposed sensor also affords excellent selectivity, reproducibility, repeatability, reversibility, and storage stability. Furthermore, the real sample analysis was carried out in blood and orange samples fallout with better recovery results.


Asunto(s)
Técnicas Electroquímicas/métodos , Compuestos de Magnesio/síntesis química , Nanopartículas del Metal/química , Rutina/análisis , Carbono/química , Citrus sinensis/química , Técnicas Electroquímicas/instrumentación , Electrodos , Análisis de los Alimentos/métodos , Humanos , Concentración de Iones de Hidrógeno , Límite de Detección , Reproducibilidad de los Resultados , Rutina/sangre , Sensibilidad y Especificidad , Temperatura
4.
ACS Appl Bio Mater ; 4(4): 3203-3213, 2021 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-35014407

RESUMEN

Herein, a hierarchical structure of flower-like NiCo layered double hydroxides (NiCo LDH) microspheres composed of three-dimensional (3D) ultrathin nanosheets was successfully synthesized via a facile hydrothermal approach. The formation of NiCo LDH was confirmed by various physicochemical studies, and the NiCo LDH-modified glassy carbon electrode was used as an efficient dual-functional electrocatalyst for non-enzymatic glucose and hydrogen peroxide (H2O2) biosensor. The host matrix of hydrotalcite NiCo LDH exhibits the enhanced electrocatalytic sensing performances with a quick response time (<3 s), wide linear range (50 nM-18.95 mM and 20 nM-11.5 mM) and lowest detection limits (S/N = 3) (10.6 and 4.4 nM) toward glucose and H2O2, and also it exhibits good stability, selectivity, and reproducibility. In addition, this biosensor was successfully utilized to the real-time detection of endogenous H2O2 produced from live cells and glucose in various biological fluids, and demonstrates that the as synthesized NiCo LDH may provide a successful pathway for physiological and clinical pathological diagnosis.


Asunto(s)
Materiales Biocompatibles/química , Técnicas Biosensibles , Técnicas Electroquímicas , Glucosa/análisis , Peróxido de Hidrógeno/análisis , Líquidos Corporales/química , Células Cultivadas , Cobalto/química , Humanos , Hidróxidos/química , Ensayo de Materiales , Níquel/química , Tamaño de la Partícula
5.
Analyst ; 146(2): 664-673, 2021 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-33206733

RESUMEN

In this work, Ni-doped ZrO2 nanoparticles (NPs) were used to decorate multi-walled carbon nanotubes (MWCNTs) to obtain a Ni-ZrO2/MWCNT nanocomposite, which acted as an efficient electrode material for the highly sensitive electrochemical detection of the anti-inflammatory drug 5-amino salicylic acid (5-ASA). The Ni-ZrO2 NPs were obtained through a facile co-precipitation method, and the subsequent support of these Ni-ZrO2 NPs onto MWCNTs was accomplished via an ultrasonication technique. Supporting Ni-ZrO2 NPs on MWCNTs not only results in excellent catalytic properties, but it also substantially enhances the surface area, electrical conductivity, and electron transfer process. The electrochemical activity of the synthesized Ni-ZrO2/MWCNT nanocomposite was systematically investigated via cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The constructed Ni-ZrO2/MWCNT-modified glassy carbon (GC) electrode manifests superior electrocatalytic oxidation activity toward 5-ASA, with a lower peak potential compared with Ni-ZrO2-NP- and MWCNT-modified GC electrodes. Importantly, the proposed biosensor exhibited excellent sensitivity during the detection of 5-ASA with a wide linear concentration range (0.001-500 µM) and a low detection limit of 0.0029 µM. Moreover, the biosensor demonstrated excellent repeatability, reproducibility, stability, and high specificity toward 5-ASA detection in the presence of different interfering species. Furthermore, the biosensor showed satisfactory recovery rates in complex biological samples, such as human blood serum, human urine, and 5-ASA tablet samples.


Asunto(s)
Electroquímica/métodos , Límite de Detección , Mesalamina/análisis , Nanopartículas/química , Nanotubos de Carbono/química , Níquel/química , Circonio/química , Humanos , Mesalamina/sangre , Mesalamina/orina , Modelos Moleculares , Conformación Molecular , Nanocompuestos/química
6.
Artículo en Inglés | MEDLINE | ID: mdl-32695763

RESUMEN

Cold atmospheric plasma jet (CAPJ) or non-thermal plasma jet has been employed in various biomedical applications based on their functions in bactericidal activity and wound healing. However, the effect of CAPJ generated by a particular composition of gases on wound closure and the underlying mechanisms that regulate wound healing signals remain elusive. In the present study, we investigated the impact of helium (He)- or a gas mixture of He and argon (He/Ar)-generated CAPJ on cell proliferation, which is a pivotal step during the wound healing process. With careful treatment duration control, He/Ar-CAPJ effectively induced keratinocyte proliferation and migration mediated through the activation of epithelial-to-mesenchymal transition (EMT) and cell cycle progression, which was evidenced by a decrease in E-cadherin levels and increases in N-cadherin, cyclin D1, Ki-67, Cdk2, and p-ERK levels. Rat wound healing studies showed that He/Ar-CAPJ treatment facilitated granulation tissue formation and mitigated inflammation in cutaneous tissue, resulting in accelerated wound closure. These findings highlight the possibility that He/Ar-CAPJ can be developed as a therapeutic agent for enhancing wound healing.

7.
Ultrason Sonochem ; 64: 104827, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31953007

RESUMEN

In this investigation, a facile sonochemical route has been developed for the preparation of porous nickel molybdate nanosheets/chitosan nanocomposite (NiMoO4/CHIT) by using ammonium molybdate and nickel(II) acetate tetrahydrate and as nickel and molybdate precursor, respectively (ultrasonic power 60 W/cm2 and frequency 20 kHz). The ultrasonic based materials preparation as a fast, convenient and economical approach has been widely used to generate novel nanomaterials. Herein, we report an efficient voltammetric sensor for amlodipine drug by using porous nickel molybdate nanosheets/chitosan nanocomposite (NiMoO4/CHIT). Its structure and properties were characterized by x-ray diffraction pattern, scanning electron microscope, transmission electron microscope, elemental analysis and mapping. The electrochemical studies are indicated the NiMoO4/CHIT modified glassy carbon electrode (GCE) exhibited the good performance towards electrocatalytic sensing of amlodipine drug. Consequently, a linear correlation between the anodic peak current with sensor concentration 0.025-373.6 µM with a detection limit and sensitivity of 4.62 nM and 4.753 µA·µM-1·cm-2, respectively. A voltammetry based drug analysis was found to be high sensitive and reproducible, which able to detect nanomolar concentration. Furthermore, the fabricated electrochemical sensor was applied in drug and biological samples.


Asunto(s)
Amlodipino/análisis , Quitosano/química , Molibdeno/química , Nanocompuestos/química , Níquel/química , Preparaciones Farmacéuticas/química , Ondas Ultrasónicas , Amlodipino/sangre , Técnicas de Química Sintética , Electroquímica , Humanos , Concentración de Iones de Hidrógeno , Nanotecnología
8.
J Clin Med ; 8(11)2019 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-31717600

RESUMEN

Using the Taguchi method to narrow experimental parameters, the antimicrobial efficiency of a cold atmospheric plasma jet (CAPJ) treatment was investigated. An L9 array with four parameters of CAPJ treatments, including the application voltage, CAPJ-sample distance, argon (Ar) gas flow rate, and CAPJ treatment time, were applied to examine the antimicrobial activity against Escherichia coli (E. coli). CAPJ treatment time was found to be the most influential parameter in its antimicrobial ability by evaluation of signal to noise ratios and analysis of variance. 100% bactericidal activity was achieved under the optimal bactericidal activity parameters including the application voltage of 8.5 kV, CAPJ-sample distance of 10 mm, Ar gas flow rate of 500 sccm, and CAPJ treatment time of 300 s, which confirms the efficacy of the Taguchi method in this design. In terms of the mechanism of CAPJ's antimicrobial ability, the intensity of hydroxyl radical produced by CAPJ positively correlated to its antimicrobial efficiency. The CAPJ antimicrobial efficiency was further evaluated by both DNA double-strand breaks analysis and scanning electron microscopy examination of CAPJ treated bacteria. CAPJ destroyed the cell wall of E. coli and further damaged its DNA structure, thus leading to successful killing of bacteria. This study suggests that optimal conditions of CPAJ can provide effective antimicrobial activity and may be grounds for a novel approach for eradicating bacterial infections.

9.
Sci Rep ; 9(1): 13075, 2019 09 10.
Artículo en Inglés | MEDLINE | ID: mdl-31506456

RESUMEN

Dopamine (DA) is a critical neurotransmitter and has been known to be liable for several neurological diseases. Hence, its sensitive and selective detection is essential for the early diagnosis of diseases related to abnormal levels of DA. In this study, we reported novel molybdenum nanoparticles self-supported functionalized multiwalled carbon nanotubes (Mo NPs@f-MWCNTs) based core-shell hybrid nanomaterial with an average diameter of 40-45 nm was found to be the best for electrochemical DA detection. The Mo NPs@f-MWCNTs hybrid material possesses tremendous superiority in the DA sensing is mainly due to the large surface area and numerous electroactive sites. The morphological and structural characteristics of the as-synthesized hybrid nanomaterial were examined by XRD, Raman, FE-SEM, HR-TEM, EDX. The electrochemical characteristics and catalytic behavior of the as-prepared Mo NPs@f-MWCNTs modified screen-printed carbon electrode for the determination of DA were systematically investigated via electrochemical impedance spectroscopy, cyclic voltammetry, and amperometry. The results demonstrate that the developed DA biosensor exhibit a low detection limit of 1.26 nM, excellent linear response of 0.01 µM to 1609 µM with good sensitivity of 4.925 µA µM-1 cm-2. We proposed outstanding appreciable stability sensor was expressed to the real-time detection of DA in the real sample analysis of rat brain, human blood serum, and DA hydrochloride injection.


Asunto(s)
Nanopartículas del Metal/química , Molibdeno/química , Nanotubos de Carbono/química , Técnicas Biosensibles , Catálisis , Técnicas de Química Sintética , Técnicas Electroquímicas , Nanopartículas del Metal/ultraestructura , Nanoestructuras , Nanotubos de Carbono/ultraestructura , Reproducibilidad de los Resultados , Difracción de Rayos X
10.
Ultrason Sonochem ; 58: 104664, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31450375

RESUMEN

We have developed a graphitic carbon nitride covered vanadium oxide nanocomposite (V2O5@g-C3N4) by a simple sonochemical approach (50 kHz and 150 W/cm2). Furthermore, the morphology and chemical composition of the V2O5@g-C3N4 nanocomposite was carried out by X-rays diffractometry (XRD), transmission electron microscopy (TEM) and electrochemical impedance spectroscopy (EIS). Furthermore, the V2O5@g-C3N4 nanocomposite modified electrode was investigate electrochemical behavior of the anticancer drug. Compared with bare SPCE, V2O5/SPCE and g-C3N4/SPCE, V2O5@g-C3N4 modified SPCE showed highest current response towards anti-cancer drug (methotrexate). Furthermore, the modified sensor exhibits with a sharp peaks and wide linear range (0.025-273.15 µM) by using DPV with the sensitivity of 7.122 µA µM-1 cm-2. Notably, we have achieved a nanomolar detection limit (13.26 nM) for the DPV detection of methotrexate. Further, the practicability of the V2O5@g-C3N4 nanocomposite modified sensor can be used for real time sensing of methotrexate in drug and blood serum samples with good recover ranges. It has potential applications in routine analysis with high specificity, excellent reproducibility and good stability.

11.
ACS Appl Mater Interfaces ; 11(8): 7862-7871, 2019 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-30698948

RESUMEN

The defect engineering makes the new concepts and designs to further enhance the electrocatalytic activity of layered structures. In this work, we demonstrated the synthesis of Mn-doped MoSe2 and reported the resultant defective sites. Subsequently, the MnMoSe2 was developed as a new type of electrocatalyst for electrochemical biosensors. The formation of defect/distortion and effective immobilization of myoglobin (Mb) were evidently confirmed by using the transmission electron microscopy and UV-vis spectroscopy analyses, respectively. The result of electrochemical impedance spectroscopy analysis reveals that the Mn doping not only helps  to enzyme immobilization but also enhances the electronic conductivity of layered material.  Owing to the multiple signal amplification strategies, the proposed Mb-immobilized MnMoSe2 (Mb@MnMoSe2) exhibited an ultralow detection limit (0.004 µM) and a higher sensitivity (222.78 µA µM-1 cm-2) of H2O2. In real-sample analysis, the Mb@MnMoSe2 showed a feasible recovery range of H2O2 detection in human serum (95.6-102.1%), urine (101.2-102.3%), and rain water (100.7-102.1%) samples. On the other hand, an in vivo study using HaCaT (7.1 × 105/mL) and RAW 264.7 (1 × 106/mL) living cells showed the feasible current responses of 0.096 and 0.085 µA, respectively. Finally, the Mn doping gives a new opportunity to fabricate a promising electrocatalyst for H2O2 biosensing.


Asunto(s)
Técnicas Biosensibles/métodos , Peróxido de Hidrógeno/análisis , Nanoestructuras/química , Animales , Dominio Catalítico , Línea Celular , Técnicas Electroquímicas , Electrodos , Enzimas Inmovilizadas/metabolismo , Humanos , Peróxido de Hidrógeno/sangre , Peróxido de Hidrógeno/orina , Límite de Detección , Manganeso/química , Ratones , Molibdeno/química , Mioglobina/química , Mioglobina/metabolismo , Células RAW 264.7 , Selenio/química
12.
RSC Adv ; 8(38): 21210-21213, 2018 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-35539957

RESUMEN

In this paper, we developed a high-performance solid-state pH sensor using a Ce0.9Sr0.1(Zr0.53Ti0.47)O4 (CSZT) membrane through a very simple sol-gel spin-coating process. The structural properties of the CSZT membrane are correlated with its sensing characteristics. The CSZT based EIS sensor exhibited a high pH sensitivity of 92.48 mV pH-1, which is beyond the Nernst limit (59.4 mV pH-1), and good reliability in terms of a low hysteresis voltage of 1 mV and a small drift rate of 0.15 mV h-1. This behaviour is attributed to the incorporation of Sr in the CSZT sensing membrane, which promotes change in the Ce oxidation state from Ce4+ to Ce3+.

13.
RSC Adv ; 8(70): 39870-39878, 2018 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-35558214

RESUMEN

To promote sustainability, the effective reutilization of electronic waste and profitable recovery of valuable materials from e-scrap are essential. A recent report showed that 500 million printer cartridges enter landfill annually, creating immense interest in establishing a facile recovery method for transforming waste toner into a ferrous resource. Furthermore, the European Union and US Food and Drug Administration have published guidelines concerning bisphenol A (BPA) use in the manufacture of thermal paper receipts. Accordingly, in this study, BPA levels in thermal receipts collected from various stores in Taiwan were detected by glassy carbon electrodes fabricated using graphene oxide-recovered Fe3O4 nanocomposites.

14.
J Colloid Interface Sci ; 514: 59-69, 2018 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-29245073

RESUMEN

Recently, the multiferroic material has fabulous attention in numerous applications owing to its excellent electronic conductivity, unique mechanical property, and higher electrocatalytic activity, etc. In this paper, we reported that the synthesis of bismuth ferrite (BiFeO3) nanosheets integrated functionalized carbon nanofiber (BiFeO3 NS/F-CNF) nanocomposite using a simple hydrothermal technique. Herein, the structural changes and crystalline property of prepared BiFeO3 NS/F-CNF nanocomposite were characterized using Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). From this detailed structural evolution, the formation of nanosheets like BiFeO3 and its nanocomposite with F-CNF were scrutinized and reported. Furthermore, the as-prepared BiFeO3 NS/F-CNF nanocomposite modified glassy carbon electrode (GCE) was applied for electrochemical detection of catechol (CC). As expected, BiFeO3 NS/F-CNF/GCE shows excellent electrocatalytic activity as well as 3.44 (F-CNF/GCE) and 7.92 (BiFeO3 NS/GCE) fold higher electrochemical redox response for CC sensing. Moreover, the proposed sensor displays a wide linear range from 0.003 to 78.02 µM with a very low detection limit of 0.0015 µM. In addition, we have validated the real-time application of our developed CC sensor in different water samples.


Asunto(s)
Bismuto/química , Carbono/química , Catecoles/análisis , Técnicas Electroquímicas , Compuestos Férricos/química , Contaminantes Químicos del Agua/análisis , Estructura Molecular , Nanocompuestos/química , Nanofibras/química , Tamaño de la Partícula , Propiedades de Superficie
15.
J Colloid Interface Sci ; 475: 46-56, 2016 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-27153217

RESUMEN

A simple and rapid green synthesis using Bischofia javanica Blume leaves as reducing agent was developed for the preparation of gold nanoparticles (AuNPs). AuNPs decorated graphene oxide (AuNPs/GO) was prepared and employed for the sensitive amperometric determination of chloramphenicol. The green biosynthesis requires less than 40s to reduce gold salts to AuNPs. The formations of AuNPs and AuNPs/GO were evaluated by scanning electron and atomic force microscopies, UV-Visible and energy dispersive X-ray spectroscopies, X-ray diffraction studies, and electrochemical methods. AuNPs/GO composite film modified electrode was fabricated and shown excellent electrocatalytic ability towards chloramphenicol. Under optimal conditions, the amperometric sensing platform has delivered wide linear range of 1.5-2.95µM, low detection limit of 0.25µM and high sensitivity of 3.81µAµM(-1)cm(-2). The developed sensor exhibited good repeatability and reproducibility, anti-interference ability and long-term storage stability. Practical feasibility of the sensor has been demonstrated in food samples (milk, powdered milk and honey) and pharmaceutical sample (eye drops). The green synthesized AuNPs/GO composite has great potential for analysis of food samples in food safety measures.


Asunto(s)
Cloranfenicol/análisis , Oro/química , Grafito/química , Miel/análisis , Nanopartículas del Metal/química , Leche/química , Soluciones Oftálmicas/química , Óxidos/química , Animales , Tamaño de la Partícula , Polvos/química , Propiedades de Superficie
16.
J Colloid Interface Sci ; 468: 163-175, 2016 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-26835586

RESUMEN

Green synthesis of Au-NPs using Cerasus serrulata (C. serrulata) leaves extract has emerged as a nontoxic and ecofriendly option, as compared to currently available chemical and/or physical methods and also Au-NPs act as both reducing and stabilizing agent. The developed Au-NPs were characterized with XRD, UV-visible spectroscopy, FTIR, SEM, TEM and chemical constituents of C. serrulata leaves extract after and before reduction of Au-NPs have been identified through GC-MS. TEM images confirmed that biosynthesized Au-NPs were spherical in shape and approximately in the range of 5-25 nm. The electrochemical results showed remarkable electrocatalytic activity of the Au-NPs-modified GC electrode in the detection of environmentally hazardous pollutant like hydrazine. The modified electrode exhibits a wide linear range 5 nM to 272 µM with low detection limit 0.05 µM. The fabricated sensor shows good selectivity towards other electroactive species as well. Thus the proposed sensor seems to be a potential candidate for developing a simple, rapid and cost-effective electrochemical sensor. The synthesized Au-NPs exhibited higher antibacterial activity against gram negative (Escherichia coli) than gram positive (Staphylococcus aureus) bacteria. DFT studies revealed that the coumarin (CM) present in the C. serrulata leaves extract demonstrated greater reducing and stabilizing properties compared to the properties of other compounds like butylhydroxytoluene (BHT) and hydrocoumarin (HCM) present in the extract.


Asunto(s)
Oro/química , Hidrazinas/análisis , Nanopartículas del Metal/química , Hojas de la Planta/química , Prunus/química , Teoría Cuántica , Extractos Vegetales/química
17.
Sci Rep ; 6: 19949, 2016 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-26818461

RESUMEN

The synthesis of highly dispersed and stable ruthenium nanoparticles (RuNPs; ca. 2-3 nm) on porous activated carbons derived from Moringa Oleifera fruit shells (MOC) is reported and were exploited for supercapacitor applications. The Ru/MOC composites so fabricated using the biowaste carbon source and ruthenium acetylacetonate as the co-feeding metal precursors were activated at elevated temperatures (600-900 (o)C) in the presence of ZnCl2 as the pore generating and chemical activating agent. The as-prepared MOC carbonized at 900 (o)C was found to possess a high specific surface area (2522 m(2) g(-1)) and co-existing micro- and mesoporosities. Upon incorporating RuNPs, the Ru/MOC nanocomposites loaded with modest amount of metallic Ru (1.0-1.5 wt%) exhibit remarkable electrochemical and capacitive properties, achiving a maximum capacitance of 291 F g(-1) at a current density of 1 A g(-1) in 1.0 M H2SO4 electrolyte. These highly stable and durable Ru/MOC electrodes, which can be facily fabricated by the eco-friendly and cost-effective route, should have great potentials for practical applications in energy storage, biosensing, and catalysis.

18.
Carbohydr Polym ; 135: 267-73, 2016 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-26453877

RESUMEN

A simple dopamine (DA) electrochemical sensor was developed based on a screen-printed carbon electrode (SPCE) modified with ß-cyclodextrin entrapped graphite (GR/ß-CD) composite for the first time. The polar hydroxyl groups on the ß-CD rims interact with polar groups of edges of GR sheets resulting into the high dispersion ability of GR in ß-CD solution. The GR/ß-CD modified electrode exhibited a higher electrochemical response to DA with a lower oxidation potential (0.224V) than that of bare/ß-CD (0.38V) and GR (0.525V) modified SPCEs, revealing an excellent electro-oxidation behavior of GR/ß-CD composite toward DA. Under optimum conditions, the fabricated sensor detects the DA in the linear concentration range from 0.1 to 58.5µM with a limit of detection of 0.011µM and the sensitivity of 1.27±0.02µAµM(-1)cm(-2). The fabricated sensor also exhibits the excellent repeatability, practicality, reproducibility, storage stability along with acceptable selectivity.


Asunto(s)
Dopamina/análisis , Grafito/química , beta-Ciclodextrinas/química , Dopamina/química , Técnicas Electroquímicas
19.
J Colloid Interface Sci ; 462: 375-81, 2016 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-26484603

RESUMEN

The research community has continuously paid much attention on the preparation of hybrid of carbon nanomaterials owing to combine their unique properties. Herein, we report the preparation of highly stable fullerene C60 (C60) wrapped graphene oxide (GO) nanocomposite by using a simple sonication method. The fabricated GO-C60 nanocomposite modified glassy carbon electrode shows a good sensitivity and lower oxidation overpotential towards dopamine (DA) than that of pristine GO and C60. The fabricated sensor detects the DA in the linear response range of 0.02-73.5µM. The limit of detection is estimated to be 0.008µM based on 3σ with a sensitivity of 4.23µAµM(-1)cm(-2). The fabricated sensor also exhibits other features such as good selectivity, stability, reproducibility and repeatability. The proposed sensor exhibits good practicality towards the detection of DA in rat brain and commercial DA injection samples.


Asunto(s)
Química Encefálica , Dopamina/análisis , Técnicas Electroquímicas , Fulerenos/química , Grafito/química , Nanocompuestos/química , Óxidos/química , Preparaciones Farmacéuticas/química , Animales , Electrodos , Tamaño de la Partícula , Ratas , Propiedades de Superficie
20.
Sci Rep ; 5: 10141, 2015 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-25998156

RESUMEN

The biomass-derived activated carbons (ACs) have been prepared with high surface areas up to 793 m(2) g(-1) is by ZnCl2 activation at three different temperatures, viz. AC700, AC800, and AC900. The AC samples were characterized by a variety of analytical and spectroscopy techniques. The as-synthesized ACs were adopted for the simultaneous electrochemical detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA). For comparison, reduced graphene oxide (RGO) was employed for the proposed sensor. The high surface area, modulated pore size and the presence of oxygen surface functional groups like heteroatoms (83.427% C, 1.085% N, 0.383% S, and 0.861% H) in the biomass-derived AC is found to be responsible for the excellent catalytic activities of biomolecules. Fascinatingly, the facile sensor further used to detect biomolecules levels in the snail hemolymph and human blood serum. Notably, the obtained analytical parameters for the biomolecules detection over the AC modified GCE, outperforming several carbon-based modified electrodes in literatures.


Asunto(s)
Ácido Ascórbico/análisis , Dopamina/análisis , Técnicas Electroquímicas , Grafito/química , Hemolinfa/metabolismo , Caracoles/metabolismo , Ácido Úrico/análisis , Animales , Ácido Ascórbico/sangre , Biomasa , Dopamina/sangre , Electrodos , Humanos , Óxidos/química , Ácido Úrico/sangre
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