scholarly journals Simultaneous Determination of Four DNA bases at Graphene Oxide/Multi-Walled Carbon Nanotube Nanocomposite-Modified Electrode

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 294 ◽  
Author(s):  
Shuting Wang ◽  
Celia Ferrag ◽  
Meissam Noroozifar ◽  
Kagan Kerman
Keyword(s):  
Graphene Oxide ◽  
Carbon Nanotube ◽  
Modified Electrode ◽  
Rate Constant ◽  
Artificial Saliva ◽  
Simultaneous Detection ◽  
Internal Standard ◽  
Active Surface ◽  
Active Surface Area ◽  
Multi Walled Carbon Nanotube

In this study, we developed a modified glassy carbon electrode (GCE) with graphene oxide, multi-walled carbon nanotube hybrid nanocomposite in chitosan (GCE/GO-MWCNT-CHT) to achieve simultaneous detection of four nucleobases (i.e., guanine (G), adenine (A), thymine (T) and cytosine (C)) along with uric acid (UA) as an internal standard. The nanocomposite was characterized using TEM and FT-IR. The linearity ranges were up to 151.0, 78.0, 79.5, 227.5, and 162.5 µM with a detection limit of 0.15, 0.12, 0.44, 4.02, 4.0, and 3.30 µM for UA, G, A, T, and C, respectively. Compared to a bare GCE, the nanocomposite-modified GCE demonstrated a large enhancement (~36.6%) of the electrochemical active surface area. Through chronoamperometric studies, the diffusion coefficients (D), standard catalytic rate constant (Ks), and heterogenous rate constant (Kh) were calculated for the analytes. Moreover, the nanocomposite-modified electrode was used for simultaneous detection in human serum, human saliva, and artificial saliva samples with recovery values ranging from 95% to 105%.

Metallic Film Modified Screen-Printed Carbon Electrode for Determination of 17α-Methyltestosterone

2019 ◽  
Vol 824 ◽  
pp. 182-189
Author(s):  
Chim Math ◽  
Wijitar Dungchai ◽  
Sudtida Pliankarom Thanasupsin
Keyword(s):  
Modified Electrode ◽  
Limit Of Detection ◽  
Diffusion Mechanism ◽  
Modified Electrodes ◽  
Active Surface ◽  
Deposition Potential ◽  
Active Surface Area ◽  
Male Population ◽  
Screen Printed Carbon Electrode ◽  
Screen Printed

17α-methyltestosterone (MT) is a synthetic androgen. It is used widely for inducing an all-male population of Nile tilapia (Oreochromis niloticus). In this work, the detection of MT was conducted using screen-printed carbon electrodes (SPCE). These were a bare electrode, a bismuth modified electrode (Bi-SPCE) and an antimony modified electrode (Sb-SPCE). The successful electrode modification was confirmed by scanning electron microscopy. The electroanalytical performance of the SPCE modified electrodes for MT detection was examined by cyclic voltammetry. The highest active surface area of 1.073x10-4 cm2 was obtained on Sb-SPCE. This indicates that Sb-SPCE can enhance the sensitivity of MT detection better than the bare-SPCE and the Bi-SPCE. The Sb-SPCE showed a linear response for MT concentrations ranging from 2 to 8 mg.L-1. The sensitivity obtained from the slope of a calibration curve was -0.452 mA.mol-1.L-1 in a Britton-Robinson buffer pH 4.0 containing Sb 16 mg.L-1 with deposition potential and deposition time of 1 V and 90 seconds, respectively. A linear relationship between the square root of the scan rate and the peak current revealed that mass transfer of MT to the electrode was driven by a diffusion mechanism. The limit of detection was found to be 1 mg.L-1.

scholarly journals Sensitive Electrochemical Detection of Caffeic Acid in Wine Based on Fluorine-Doped Graphene Oxide

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1604 ◽  
Author(s):  
Venkatesh Manikandan ◽  
Boopathi Sidhureddy ◽  
Antony Thiruppathi ◽  
Aicheng Chen
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Caffeic Acid ◽  
Photoelectron Spectroscopy ◽  
Limit Of Detection ◽  
Active Surface ◽  
Differential Pulse ◽  
Active Surface Area ◽  
Food And Beverage ◽  
Doped Graphene

We report here a novel electrochemical sensor developed using fluorine-doped graphene oxide (F-GO) for the detection of caffeic acid (CA). The synthesized graphene oxide (GO) and F-GO nanomaterials were systematically characterized with a scanning electron microscope (SEM), and the presence of semi-ionic bonds was confirmed in the F-GO using X-ray photoelectron spectroscopy. The electrochemical behaviours of bare glassy carbon electrode (GCE), F-GO/GCE, and GO/GCE toward the oxidation of CA were studied using cyclic voltammetry (CV), and the results obtained from the CV investigation revealed that F-GO/GCE exhibited the highest electrochemically active surface area and electrocatalytic activity in contrast to the other electrodes. Differential pulse voltammetry (DPV) was employed for the analytical quantitation of CA, and the F-GO/GCE produced a stable oxidation signal over the selected CA concentration range (0.5 to 100.0 μM) with a low limit of detection of 0.018 μM. Furthermore, the acquired results from the selectivity studies revealed a strong anti-interference capability of the F-GO/GCE in the presence of other hydroxycinnamic acids and ascorbic acid. Moreover, the F-GO/GCE offered a good sensitivity, long-term stability, and an excellent reproducibility. The practical application of the electrochemical F-GO sensor was verified using various brands of commercially available wine. The developed electrochemical sensor successfully displayed its ability to directly detect CA in wine samples without pretreatment, making it a promising candidate for food and beverage quality control.

Simultaneous determination of dopamine, ascorbic acid and uric acid using a multi-walled carbon nanotube and reduced graphene oxide hybrid functionalized by PAMAM and Au nanoparticles

2015 ◽  
Vol 7 (4) ◽  
pp. 1471-1477 ◽  
Author(s):  
Siyuan Wang ◽  
Wen Zhang ◽  
Xia Zhong ◽  
Yaqin Chai ◽  
Ruo Yuan
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Graphene Oxide ◽  
Carbon Nanotube ◽  
Simultaneous Determination ◽  
Au Nanoparticles ◽  
Electrochemical Determination ◽  
Multi Walled Carbon Nanotube ◽  
Reduced Graphene

A nanohybrid (RGO–PAMAM–MWCNT–AuNPs) for simultaneous electrochemical determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA) was reported in this paper.

Self-assembly fabrication of a graphene/multi-walled carbon nanotube hybrid material for suppressing potential heat radiation and toxic effluent

RSC Advances ◽  
2015 ◽  
Vol 5 (125) ◽  
pp. 103365-103372 ◽  
Author(s):  
Lei Liu ◽  
Dong Wang ◽  
Yuan Hu
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Graphene Oxide ◽  
Carbon Nanotube ◽  
Hybrid Material ◽  
Self Assembly ◽  
Heat Radiation ◽  
Multi Walled Carbon Nanotube ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Negative graphene oxide was combined with positive chitosan-modified multi-walled carbon nanotubes in aqueous solution and then thermally reduced to fabricate a multi-walled carbon nanotube/graphene (MWCNT/G) hybrid material.

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