scholarly journals Electrochemical Sensing of Nitric Oxide on Electrochemically Reduced Graphene-Modified Electrode

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Yu-Li Wang ◽  
Guang-Chao Zhao

Graphene-modified electrode was prepared through electrochemically reducing graphene oxide on the surface of a glassy carbon electrode in PBS solution. The as-prepared electrode owns higher stability and stronger catalytic activity towards the oxidation of nitric oxide (NO). At the electrode, an oxidation peak of NO can be observed at about 1.05 V (versus Ag/AgCl), and the electrode reaction of NO is controlled by diffusion process. Under the optimum conditions, the peak currents are dependent linearly on NO concentrations in the range from to  M with a limit of detection of  M. The response time of the as-prepared electrode to NO is less than 3 s, and the sensitivity is about 299.1 μA/mM, revealing that the electrode can be used as an excellent sensor for the determination of NO. With further modification of Nafion, the determination is free from the interference of nitrite and some other biological substances. This investigation provides an alternate way for the determination of NO.

A modified glassy carbon electrode (GCE) compositing multi-walled carbon nanotubes (MWCNTs), Nafion and bismuth film was prepared and applied for the sensitive detection of trace Pb (II). MWCNTs were dispersed into ethanol by ultrasonication in the presence of Nafion and the nanotubes are coated onto the bare GCE. After that, an extra Nafion adhesion agent is added to the electrode. By the in situ plating, a bismuth film was fabricated on the MWCNTs-NA/GCE, making the desired electrode, MWCNTs-NA-Bi/GCE. The modified electrode was characterized by differential pulse anodic stripping voltammetry, scanning electron microscopy, and cyclic voltammetry. A deposition potential of –1.4 V (vs. Ag/AgCl) and a deposition time of 300 s were applied to the working electrode under stirred conditions after optimizing. Nanotubes and Nafion concentrations and pH were carefully optimized to determine trace lead ions by using the electrode as an electrochemical-sensing platform. Nafion effectively increased the stability and adhesivity of the composite film. The MWCNTs-NA-Bi film modified electrode can remarkably increase the anodic peak current of Pb2+. The sensitivity of MWCNTs-NA-Bi/GCE is 4.35 times higher than that of the bare GCE with bismuth film. The prepared electrode showed excellent stability and reproducibility and can be applied for determination of Pb2+ contained wastewater.


2020 ◽  
Author(s):  
Miao Liu ◽  
Mingxuan Jia ◽  
Dong Hui Li

Abstract An innovative method for the determination of isoniazid tablets is studied through electrochemical method for the modification of glassy carbon electrode (GCE). Polyoxomolybdate, with stable structures, has not been widely used for the determination of substance. In this study, the mentioned polyoxomolybdate was characterized by Fourier transform infrared spectroscopy (FT-IR), UV-vis, X-ray diffraction (XRD), Atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS), and used to modify the glassy carbon electrode. The electrochemical performance of the polyoxomolybdate@GCE was investigated with cyclic voltammetry (CV) and differential pulse voltammetry (DPV), compared with the unmodified electrode, the proposed polyoxomolybdate modified electrode exhibited strong electro-catalytic activities towards isoniazid (INH). Under the optimized conditions, there was linear relationships between the DPV peak currents and the concentrations in the range of 1 × 10 -7 g/L to 3 × 10 -7 g/L for INH (R 2 = 0.9979), with the limit of detection (LOD) of 0.024 μg/L (based on S/N = 3). The modified electrode has proper reproducibility (RSD < 5%), stability, response time (< 3 min) and lifetime (up to 6 days).


2020 ◽  
Vol 17 (1) ◽  
pp. 40-46
Author(s):  
Vanitha Vasantharaghavan ◽  
Ravichandran Cingaram

Background: The Glassy Carbon Electrode (GCE) was modified with zinc oxide nanoparticles to enhance the electrocatalytic activity of the redox behavior of cefotaxime ion. ATOMIC Force Microscopy (AFM) photographic studies showed the nanorod like structure of the zinc oxide, which was coated uniformly on the electrode surface. Methods: The zinc oxide nanorod modified electrode was used as novel voltammetric determination of cefotaxime. The results of voltammetric behavior are satisfactory in the electro oxidation of cefotaxime, and exhibit considerable improvement compared to glassy carbon electrode. Results: Under the optimized experimental conditions, the ZnO nanorod modified electrode exhibit better linear dynamic range from 300 ppb to 700 ppb with lower limit of detection 200 ppb for the stripping voltammetric determination of cefotaxime. Conclusion: The pharmaceutical and clinical formulation of cefotaxime was successfully applied for accurate determination of trace amounts on ZnO nanomateials modified electrode.


2016 ◽  
Vol 183 (11) ◽  
pp. 3077-3085 ◽  
Author(s):  
Ab Rahman Marlinda ◽  
Alagarsamy Pandikumar ◽  
Subramaniam Jayabal ◽  
Norazriena Yusoff ◽  
Abu Bakar Suriani ◽  
...  

2013 ◽  
Vol 785-786 ◽  
pp. 508-511
Author(s):  
Ying Zhang ◽  
Guo Bao Li ◽  
Qiu Xia Yang

The titanium sol was prepared by depositing the organic titanium on glassy carbon electrode surface. Electrophoresis time and the applied voltage as well can markedly influence the electrochemical behavior of the nanoTiO2film. In contrast with bare glassy carbon electrode, the nanoTiO2film on glassy carbon electrode had a good electrocatalytic activity to dopamine (DA) and uric acid (UA) in PBS solution. The result showed that there was a linear relationship between the oxidation peak currents and the concentration of DA from 8.0×10-6to 4.0×10-4mol·L-1by differential pulse voltammetry (DPV) and there was a linear relationship between the oxidation peak currents and the concentration of UA from 8×10-6to 1.0×10-3mol·L-1. This modified electrode was quite effective to detect DA and UA in simultaneous determination of these species in a mixture.


RSC Advances ◽  
2016 ◽  
Vol 6 (24) ◽  
pp. 19982-19991 ◽  
Author(s):  
Demudu Babu Gorle ◽  
Manickam Anbu Kulandainathan

We prepared a reduced graphene oxide/poly(methylene blue) composite on a glassy carbon electrode surface and electrografted dopamine onto the surface for the sensing of dopamine.


Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 958 ◽  
Author(s):  
Quanguo He ◽  
Jun Liu ◽  
Yaling Tian ◽  
Yiyong Wu ◽  
Felista Magesa ◽  
...  

In this paper, the preparation, characterization, and electrochemical application of Cu2O nanoparticles and an electrochemical reduced graphene oxide nanohybrid modified glassy carbon electrode (denoted as Cu2O NPs‒ERGO/GCE) are described. This modified electrode was used as an electrochemical sensor for the catalytic oxidation of rhodamine B (RhB), and it exhibited an excellent electrochemical performance for RhB. The oxidation potential of RhB was decreased greatly, and the sensitivity to detect RhB was improved significantly. Under optimum conditions, a linear dynamic range of 0.01–20.0 μM and a low detection limit of 0.006 μM were obtained with the Cu2O NPs‒ERGO/GCE by using second‒order derivative linear sweep voltammetry. In addition, the selectivity of the prepared modified electrode was analyzed for the determination of RhB. The practical application of this sensor was investigated for the determination of RhB in food samples, and satisfactory results were obtained.


2013 ◽  
Vol 781-784 ◽  
pp. 89-92
Author(s):  
Qiu Xia Yang ◽  
Wei Ping Sui ◽  
Da Wei Fan ◽  
Guo Bao Li

The poly-histidine (poly-HTD) film was prepared at glassy carbon electrode by electropolymerization, and its electrochemical behavior was investigated by cyclic voltammetry. Results show that the behavior of this poly-HTD film is in good agreement with quasi-reversible process characteristic. At low scan rates, the electronic transfer process of electrode reaction is controlled by surface process. At this poly-HTD film modified electrode, an excellent electrocatalytic ability towards the redox of hydroquinone (HQ) and catechol (CC) with decrease of the overpotential and improvement of the redox peak currents was found. Differential pulse voltammetry was used for the simultaneous determination of HQ and CC in their mixture, and the peak-to-peak separation ΔEpfor HQ and CC was 110 mV. Therefore, this polymer modified electrode can be used for the simultaneously selective determination of HQ and CC without interference with each other.


2012 ◽  
Vol 161 ◽  
pp. 255-259 ◽  
Author(s):  
Mei Feng Chen ◽  
Xin Ying Ma ◽  
Xia Li

Graphene-modified glassy carbon electrode was made by dropping. In phosphate-citric acid buffered saline, the modified electrode was shown to possess an excellent selective electrocatalytical effect on the redox of catechol, and further used to determine catechol in the presence of resorcin and hydroquinone by cyclic voltammetry. The oxidation peak currents Ipa showed a linear relationship with the concentrations (c) of catechol in the range of 2.97×10-7 mol•L-1~9.31×10-6 mol•L-1 and 9.31×10-6 mol•L-1~1.03×10-4 mol•L-1 with a correlation coefficient as follows: Ipa1(A)= -4.10×10-6-2.31c, R=0.Superscript text9971; Ipa2 (A) =-1.50×10-5-0.60c, R=0.9953, respectively, and the detection limit is 2.50×10-8 mol•L-1. The modified electrode is high sensitivity, selectivity, stability, and has been successfulSuperscript textly applied to analyzing catechol in wastewater.


2020 ◽  
Author(s):  
Miao Liu ◽  
Dong hui Li ◽  
Ming xuan Jia

Abstract An innovative method for the determination of isoniazid tablets is studied through electrochemical method for the modification of glassy carbon electrode (GCE). Polyoxomolybdate, with stable structures, has not been widely used for the determination of substance. In this study, the mentioned polyoxomolybdate was characterized by Fourier transform infrared spectroscopy (FT-IR), UV-vis, X-ray diffraction (XRD), Atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS), and used to modify the glassy carbon electrode (GCE). The electrochemical performance of the polyoxomolybdate@GCE was investigated with cyclic voltammetry (CV) and differential pulse voltammetry (DPV), compared with the unmodified electrode, the proposed polyoxomolybdate modified electrode exhibited strong electro-catalytic activities towards isoniazid (INH). Under the optimized conditions, there was linear relationships between the DPV peak currents and the concentrations in the range of 1 × 10 -7 g/L to 3 × 10 -7 g/L for INH (R 2 = 0.9979), with the limit of detection (LOD) of 0.024 μg/L (based on S/N = 3). The modified electrode has proper reproducibility (RSD < 5%), stability, response time (< 3 min) and lifetime (up to 6 days).


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