Synthesis of ordered mesoporous carbon/cobalt oxide nanocomposite for determination of glutathione

Selective determination of epinephrine using electrochemical sensor based on ordered mesoporous carbon / nickel oxide nanocomposite

A nanocomposite of ordered mesoporous carbon/nickel oxide (OMC-NiO) was synthesized by hard-templating method. The nanocomposite remained ordered mesostructure and high surface area with the NiO nanocrystals embedded in the wall of the OMC. A sensitive sensor for electrochemical detection of epinephrine (EP) was developed with GCE modified by OMC-NiO nanocomposite. Cyclic voltammogram (CV) and differential pulse voltammetry (DPV) were used as the techniques to explore the electrochemical behavior of EP on OMC-NiO/GCE surface. The result showed that the electrode demonstrated better electrocatalytic performance to EP compared to that seen at OMC/GCE. Under the optimum condition, DPV measurements of the electrode response displayed a linear detection range for 8.0 × 10^-7 to 5.0 × 10^-5 M with a detection limit of 8.5 × 10^-8 M (S/N = 3). It is worth noting that the electrocatalytic redox mechanism of EP on the electrode have studied through experiments and calculations (cyclic voltammetry and molecular electrostatic potential distribution). Moreover, the electrocatalytic behavior for the oxidation of EP and uric acid (UA) on OMC-NiO/GCE surface was investigated. The result showed that the sensor can be used to selectively determinate EP in the presence of an excesses of UA. Finally, the developed sensor was successfully applied to the determination of EP in spiked human blood serum and EP injection with satisfactory results.

A Solid-state Electrochemiluminescence Sensor for Detecting Glutathione with a Graphite-phase Carbon Nitride/Silica Modified Glassy Carbon Electrode

A solid-state electrochemiluminescence (ECL) sensor for the detection of reduced glutathione (GSH) based on a g-C₃N₄/SiO₂ modified glass carbon electrode (GCE) has been developed in this research. The g-C₃N₄, which is employed as a luminophore, is simply prepared and exhibits an excellent ECL response. Mesoporous silica hollow spheres (SiO₂) with a large specific surface area are introduced here to increase the loading amount of g-C₃N₄. Compared to a g-C₃N₄ modified GCE, the g-C₃N₄/SiO₂ modified GCE displays a much higher ECL intensity. A high enhancement effect on the ECL intensity of g-C₃N₄/SiO₂ modified GCE is obtained in the presence of GSH in the electrolyte. Moreover, the enhanced ECL intensity shows a good linear relationship to the GSH concentration in the range from 1.0 × 10^-7 to 5.0 × 10^-4 M, with a detection limit of 2.0 × 10^-8 M (6.1 ng/mL). Besides, the ECL sensor exhibits a good anti-interference ability and has been successfully applied in the detection of GSH in commercial samples. The proposed sensor provides a promising platform for life science.

Facile synthesis of Co3O4 disordered circular sheets for selective electrochemical determination of nitrite

The electrochemical nitrite sensing properties of a cobalt oxide (Co₃O₄) modified glassy carbon electrode were investigated.

One-pot synthesis of Ni nanoparticle/ordered mesoporous carbon composite electrode materials for electrocatalytic reduction of aromatic ketones

A simple one-pot synthesis of Ni nanoparticle/ordered mesoporous carbon composite electrode materials is demonstrated for electrosynthesis for the first time. The obtained nanocomposites have uniform mesopore sizes (3.0-3.7 nm), large specific surface areas (506-633 m² g^-1), high pore volumes (0.28-0.38 cm³ g^-1), well-graphitized carbon frameworks, and uniformly dispersed Ni nanoparticles (7-15 nm) embedded in the carbon pore walls. The prepared materials show very high performance in the selective (∼84%) electrocatalytic reduction of aromatic ketones into alcohols (∼79%).

Sonochemical synthesis of silver nanoparticles anchored reduced graphene oxide nanosheets for selective and sensitive detection of glutathione

Developed here an eco-friendly, one-pot approach toward rapid synthesis of silver nanoparticles anchored reduced graphene oxide (AgNPs_(TMSPED)-rGO) nanosheets via sonochemical irradiation method, using an aqueous solution mixture of GO and AgNO₃ in the presence of N-[3(trimethoxysilyl)propyl] ethylenediamine (TMSPED) without any reducing agent. As synthesized decorated nanosheets was thoroughly characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Pristine AgNPs_(TMSPED), pristine rGO_(TMSPED) and as prepared AgNPs_(TMSPED)-rGO materials were employed to modify the glassy carbon (GC) electrode and demonstrated its excellent electrocatalytic activities towards glutathione (GSH). Voltammetry and amperometry measurements were utilized to assess the electrochemical properties towards the glutathione detection. When the Ag nanoparticles were anchored onto the rGO surface, the observed results illustrated that the electrocatalytic properties of rGO might be enhanced. The resulting sensor exhibits excellent repeatability and long-term stability. Furthermore, AgNPs_(TMSPED)-rGO/GC electrode able to be employed for the selective determination of GSH in amperometric analysis in the presence of ascorbic acid (AA), dopamine (DA), uric acid (UA) and glucose. Finally, this modified electrode was effectively applied to determine glutathione in real samples with good recoveries.

Recent Trends on Electrochemical Sensors Based on Ordered Mesoporous Carbon

The past decade has seen an increasing number of extensive studies devoted to the exploitation of ordered mesoporous carbon (OMC) materials in electrochemistry, notably in the fields of energy and sensing. The present review summarizes the recent achievements made in field of electroanalysis using electrodes modified with such nanomaterials. On the basis of comprehensive tables, the interest in OMC for designing electrochemical sensors is illustrated through the various applications developed to date. They include voltammetric detection after preconcentration, electrocatalysis (intrinsically due to OMC or based on suitable catalysts deposited onto OMC), electrochemical biosensors, as well as electrochemiluminescence and potentiometric sensors.

Glassy carbon electrode modified with 7,7,8,8-tetracyanoquinodimethane and graphene oxide triggered a synergistic effect: Low-potential amperometric detection of reduced glutathione

A sensitive electrochemical sensor based on the synergistic effect of 7,7,8,8-tetracyanoquinodimethane (TCNQ) and graphene oxide (GO) for low-potential amperometric detection of reduced glutathione (GSH) in pH 7.2 phosphate buffer solution (PBS) has been reported. This is the first time that the combination of GO and TCNQ have been successfully employed to construct an electrochemical sensor for the detection of glutathione. The surface of the glassy carbon electrode (GCE) was modified by a drop casting using TCNQ and GO. Cyclic voltammetric measurements showed that TCNQ and GO triggered a synergistic effect and exhibited an unexpected electrocatalytic activity towards GSH oxidation, compared to GCE modified with only GO, TCNQ or TCNQ/electrochemically reduced GO. Three oxidation waves for GSH were found at -0.05, 0.1 and 0.5V, respectively. Amperometric techniques were employed to detect GSH sensitively using a GCE modified with TCNQ/GO at -0.05V. The electrochemical sensor showed a wide linear range from 0.25 to 124.3μM and 124.3μM to 1.67mM with a limit of detection of 0.15μM. The electroanalytical sensor was successfully applied towards the detection of GSH in an eye drop solution.

A regular “signal attenuation” electrochemical aptasensor for highly sensitive detection of streptomycin

A novel aptasensor based on PCNRs and MWCNTs–CuO–AuNPs as the nanomatrix was constructed for the highly sensitive detection of streptomycin.

Mesoporous ZnS-NiS Nanocomposites for Nonenzymatic Electrochemical Glucose Sensors

Mesoporous ZnS-NiS composites are prepared via ion- exchange reactions using ZnS as the precursor. The prepared mesoporous ZnS-NiS composite materials have large surface areas (137.9 m(2) g(-1)) compared with the ZnS precursor. More importantly, the application of these mesoporous ZnS-NiS composites as nonenzymatic glucose sensors was successfully explored. Electrochemical sensors based on mesoporous ZnS-NiS composites exhibit a high selectivity and a low detection limit (0.125 μm) toward the oxidation of glucose, which can mainly be attributed to the morphological characteristics of the mesoporous structure with high specific surface area and a rational composition of the two constituents. In addition, the mesoporous ZnS-NiS composites coated on the surface of electrodes can be used to modify the mass transport regime, and this alteration can, in favorable circumstances, facilitate the amperometric discrimination between species. These results suggest that such mesoporous ZnS-NiS composites are promising materials for nonenzymatic glucose sensors.

A novel gold nanoparticle decorated nanocrystalline zeolite based electrochemical sensor for the nanomolar simultaneous detection of cysteine and glutathione

High electrocatalytic activity of the sensor can be attributed to the highly dispersed gold nanoparticles on the nanocrystalline zeolite matrix.

Cobalt oxide functionalized nanoporous carbon electrodes and their excellent supercapacitive performance

Nanoporous carbon (CMK-3-150) functionalized with different amounts of cobalt oxide (CoO) nanoparticles was synthesized by an incipient wetness impregnation technique for supercapacitor application.

Highly sensitive determination of reduced glutathione based on a cobalt nanoparticle implanted-modified indium tin oxide electrode

Cobalt nanoparticle modified indium tin oxide (CoNP/ITO) electrodes fabricated by ion implantation were applied for the detection of reduced glutathione (GSH).

Application of cobalt oxide nanostructured modified aluminium electrode for electrocatalytic oxidation of guanine and single-strand DNA

The electrocatalytic oxidation of guanine in ssDNA at cobalt oxide nanoflower-modified aluminium electrode.