Application of cetyltrimethylammonium bromide – graphene modified electrode for sensitive determination of caffeine

2011 ◽  
Vol 89 (6) ◽  
pp. 697-702 ◽  
Author(s):  
Jun-Yong Sun ◽  
Ke-Jing Huang ◽  
Shuai-Yun Wei ◽  
Zhi-Wei Wu
Keyword(s):  
Modified Electrode ◽  
Cetyltrimethylammonium Bromide ◽  
Electrochemical Sensors ◽  
Signal To Noise Ratio ◽  
Soft Drink ◽  
Differential Pulse ◽  
Experimental Conditions ◽  
Long Term Stability ◽  
Good Electrocatalytic Activity ◽  
Sensitive Determination

An electrochemical sensor based on a cationic surfactant cetyltrimethylammonium bromide (CTAB) – dispersed graphene (Gr) system for sensitive detection of caffeine is presented. The electrochemical behavior of caffeine on the modified glassy carbon electrode was investigated by cyclic voltammetry and differential pulse voltammetry. The results showed that the modified electrode exhibited good electrocatalytic activity to the oxidation of caffeine. Under the optimized experimental conditions, caffeine was detected in the concentration range from 0.3 to 100 µmol L–1 with a detection limit of 91 nmol L–1 at a signal-to-noise ratio = 3. The biosensor exhibited some advantages over other electrochemical sensors, such as long-term stability, satisfactory recovery (98.1%−102.3%), and good reproducibility (RSD = 5.1%). The practical application of the developed method was verified in soft-drink sample analysis.

An Amperometric Immunosensor for α-Fetoprotein Based on Antibody Coated Nano ZrO2-Au-Poly Lysine Composite Membrane Modified Electrode

2011 ◽  
Vol 343-344 ◽  
pp. 490-496 ◽  
Author(s):  
Yuan Zhao Wu ◽  
Fu Tao Hu ◽  
Ning Gan ◽  
Jian Guo Hou ◽  
Tian Hua Li ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Composite Membrane ◽  
Electrochemical Impedance ◽  
Signal To Noise Ratio ◽  
Cost Effective ◽  
Differential Pulse ◽  
Phenoxyacetic Acid ◽  
Serum Samples ◽  
Amperometric Immunosensor ◽  
Sensitivity And Selectivity

One novel amperometric immunosensor for α-fetop- rotein was fabricated which was modified by antibody immobilized on nano ZrO2-Au-polyLysine composite membrane. Firstly, the deoxyribonucleic acid – phenoxyacetic acid isoniazid- Schiff base Co(II) complex (DNA-CoL) mixture film was casted on surface of multi carbon nanotubes(MWCNTs) modified glassy carbon electrode(GCE/CNTs/DNA-CoL). Then the composite nanoparticles (ZrO2-Au-pLL) was employed to immobilize the antibody of α-fetoprotein(AFP) to produce the probes(ZrO2-Au-pLL-anti AFP) for AFP. Finally the probes were modified on GCE/CNTs/DNA-CoL through the specific connection between DNA and ZrO2 to form a novel nanocomposite membrane immunosensor for AFP(GCE/CNTs/ DNA-CoL/ZrO2-Au–pLL-anti AFP). The function of immunosensor was investigated by scanning electron microscopy (SEM), cyclic voltammetry(CV), differential pulse voltammety (DPV) and electrochemical impedance spectroscopy experiment (EIS). The results indicated that combining the advantages of the MWNTs-DNA material and ZrO2-Au-pLL-anti AFP nano probes, the immunosensor with excellent sensitivity and selectivity to AFP was prepared successfully. The modified electrode was sensitive to AFP with a linear relationship between 0.05 and 10 ng · mL−1 and a correl- ation coefficient of 0.9905. The detection limit at a signal to noise ratio of 3 was 0.01 ng·mL−1 under the optimal conditions. The described immunosensor preparation and immunoassay methods offer promise for simple and cost-effective analysis of AFP in serum samples.

scholarly journals Novel Electrochemical Sensor Fabricated for Individual and Simultaneous Ultrasensitive Determination of Olaquindox and Carbadox Based on MWCNT-OH/CMK-8 Hybrid Nanocomposite Film

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3041 ◽  
Author(s):  
Yanqing Liu ◽  
Gengxin Hu ◽  
Hongwu Wang ◽  
Su Yao ◽  
Yinjian Ye
Keyword(s):  
Electrochemical Sensor ◽  
Simultaneous Determination ◽  
Modified Electrode ◽  
Electrochemical Impedance ◽  
Modified Electrodes ◽  
Differential Pulse ◽  
Hybrid Nanocomposite ◽  
Experimental Conditions ◽  
Linear Relationships

A hybrid nanocomposite consisting of hydroxylated multi-walled carbon nanotubes (MWCNTs−OH) and cube mesoporous carbon (CMK−8) was applied in this study to construct an MWCNT−OH/CMK−8/gold electrode (GE) electrochemical sensor and simultaneously perform the electro-reduction of olaquindox (OLA) and carbadox (CBX). The respective peak currents of CBX and OLA on the modified electrode increased by 720- and 595-fold relative to the peak current of GE. The performances of the modified electrode were investigated with electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry. Then, the modified electrodes were used for the individual and simultaneous determination of OLA and CBX. The fabricated sensor demonstrated a linear response at 0.2–500 nmol/L in optimum experimental conditions, and the detection limits were 104.1 and 62.9 pmol/L for the simultaneous determination of OLA and CBX, respectively. As for individual determination, wide linear relationships were obtained for the detected OLA with levels of 0.05–500 nmol/L with LOD of 20.7 pmol/L and the detected CBX with levels of 0.10–500 nmol/L with LOD of 50.2 pmol/L. The fabricated sensor was successfully used in the independent and simultaneous determination of OLA and CBX in spiked pork samples.

Electrochemical Sensor for the Determination of Paracetamol at Carbamazepine Film Coated Carbon Paste Electrode

2018 ◽  
Vol 232 (3) ◽  
pp. 345-358 ◽  
Author(s):  
Amit B. Teradale ◽  
Shekappa D. Lamani ◽  
Pattan S. Ganesh ◽  
Bahaddurghatta E. Kumara Swamy ◽  
Swastika N. Das
Keyword(s):  
Modified Electrode ◽  
Carbon Paste Electrode ◽  
Carbon Paste ◽  
Cyclic Voltammetric ◽  
Experimental Conditions ◽  
Long Term Stability ◽  
Noticeable Improvement ◽  
Coated Carbon ◽  
Paste Electrode ◽  
Voltammetric Technique

AbstractThe electrochemical behavior of paracetamol (PC) was investigated at carbamazepine (CBZ) film coated carbon paste electrode in 0.2 M PBS of pH 7.4 by cyclic voltammetric technique. The modified electrode was exhibited a good electrochemical activity towards the oxidation of paracetamol, which results in a noticeable improvement of the peak currents and feasible oxidation as compared to the bare carbon paste electrode. Under optimal experimental conditions the electrochemical response to PC was linear in the concentration range from 1.0×10−4M to 3.94×10−4M with a detection limit of 0.24 μM by cyclic voltammetric technique. The sensitivity, long-term stability, reproducibility was shown by the modified electrode. Finally, the proposed method was successfully applied to determine PC in pharmaceutical samples.

scholarly journals Glassy carbon electrode modified with poly(taurine)/TiO2-graphene composite film for determination of acetaminophen and caffeine

2013 ◽  
Vol 19 (3) ◽  
pp. 359-368 ◽  
Author(s):  
Xiao-Qin Xiong ◽  
Ke-Jing Huang ◽  
Chun-Xuan Xu ◽  
Chun-Xue Jin ◽  
Qiu-Ge Zhai
Keyword(s):  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Electrochemical Sensors ◽  
Differential Pulse ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Electrochemical Behaviors ◽  
Potential Applications ◽  
Graphene Nanocomposite

A novel electrochemical sensor poly(taurine)/TiO2-graphene nanocomposite modified glassy carbon electrode (PT/TiO2-Gr/GCE) was fabricated. This sensor was based on an electrochemically polymerized taurine layer on a TiO2-graphene modified glassy carbon electrode. The electrochemical behaviors of acetaminophen and caffeine at the modified electrode were studied by cyclic voltammetry and differential pulse voltammetry. The results showed that the oxidation peak currents of acetaminophen and caffeine were linear with their concentrations in the range of 1?10-7-9?10-5 M and 2.5?10-5-2?10-4 M, respectively. The detection limits of acetaminophen and caffeine were 3.4?10-8 M and 5.0?10-7 M, respectively (S/N=3). This modified electrode showed good sensitivity and stability, which had promising potential applications in electrochemical sensors and biosensors design.

Electrocatalytic Property Toward Dopamine and Uric Acid of the Nanoparticles TiO2 Modified Electrode

2013 ◽  
Vol 785-786 ◽  
pp. 508-511
Author(s):  
Ying Zhang ◽  
Guo Bao Li ◽  
Qiu Xia Yang
Keyword(s):  
Uric Acid ◽  
Linear Relationship ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Differential Pulse ◽  
Carbon Electrode ◽  
Oxidation Peak ◽  
Good Electrocatalytic Activity

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.

scholarly journals Spot on Gold Nanoparticles/Silica Modified Electrode for Rapid Sensitive Determination of Dinoprostone

2019 ◽  
pp. 17-22 ◽  
Author(s):  
Shimaa A Atty ◽  
Mohammed Walash ◽  
Safaa Toubar ◽  
Maha M AbouEl-Alamin ◽  
Maha A Elabd ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Pharmaceutical Preparation ◽  
Electrochemical Sensing ◽  
Modified Carbon Paste Electrode ◽  
Official Method ◽  
Carbon Paste ◽  
Experimental Conditions ◽  
Sensing Platform ◽  
Sensitive Determination

A novel simple and selective electrochemical procedure is utilized for the determination of Dinoprostone (DIN) in drug substance and pharmaceutical preparation with good recovery and without interference with other excipient. Herein, the electrochemical sensing platform based upon preparing gold nanoparticle sensor on silica modified carbon paste electrode. The surface morphology of the modified electrode was characterized by scanning electron microscope. Different experimental conditions, including electrode composition, effect of pH and scan rate were estimated carefully by cyclic voltammetry to obtain the highest electrochemical response. By using square wave voltammetry a good linear response was obtained in the range of, 2 x 10-5-4 x10-4 mol L-1, and 2 x 10-7-1.6 x 10-4 mol L-1, with low detection limit of 5 x 10-6 mol L-1, and 4.9 x 10-8 mol L-1 by CPE and GNP/SMCPE respectively. The obtained results are in good agreement with those obtained by official method. No electrochemical method was reported before for determination of DIN. The developed method was simple, rapid, economic and challenging to green analytical chemistry.

A comparative study on the cold type and thermal type field emission guns used in the same electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 58-59
Author(s):  
M. Iwatsuki ◽  
Y. Kokubo ◽  
Y. Harada
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Signal To Noise Ratio ◽  
Electron Source ◽  
Resolving Power ◽  
Optical Source ◽  
Experimental Conditions ◽  
High Brightness ◽  
Illumination System ◽  
Transmission Electron

On accout of its high brightness, small optical source size, and minimal energy spread, the field emission gun (FEG) has the advantage that it provides the conventional transmission electron microscope (TEM) with a highly coherent illumination system and directly improves the resolving power and signal-to-noise ratio of the scanning electron microscope (SEM). The FEG is generally classified into two types; the cold field emission (C-FEG) and thermal field emission gun (T-FEG). The former, in which a field emitter is used at the room temperature, was successfully developed as an electron source for the SEM. The latter, in which the emitter is heated to the temperature range of 1000-1800°K, was also proved to be very suited as an electron source for the TEM, as well as for the SEM. Some characteristics of the two types of the FEG have been studied and reported by many authors. However, the results of the respective types have been obtained separately under different experimental conditions.

A Sensitive and Selective Electrochemical Sensor for Sulfadimethoxine Based on Electropolymerized Molecularly Imprinted Poly (o-aminophenol) Film

2020 ◽  
Vol 16 (4) ◽  
pp. 413-420 ◽  
Author(s):  
Youyuan Peng ◽  
Qiaolan Ji
Keyword(s):  
Electrochemical Sensor ◽  
Polymer Film ◽  
Water Samples ◽  
Differential Pulse ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Long Term Stability ◽  
Multi Walled Carbon Nanotubes ◽  
Aquaculture Water ◽  
Walled Carbon Nanotubes

Background: As a broad-spectrum antibiotic of the sulfonamide family, Sulfadimethoxine (SDM) has been widely utilized for therapeutic and growth-promoting purposes in animals. However, the use of SDM can cause residual problems. Even a low concentration of SDM in the aquatic system can exert toxic effects on target organisms and green algae. Therefore, the quantitation of SDM residues has become an important task. Methods: The present work describes the development of a sensitive and selective electrochemical sensor for sulfadimethoxine based on molecularly imprinted poly(o-aminophenol) film. The molecular imprinted polymer film was fabricated by electropolymerizing o-aminophenol in the presence of SDM after depositing carboxylfunctionalized multi-walled carbon nanotubes onto a glassy carbon electrode surface. SDM can be quickly removed by electrochemical methods. The imprinted polymer film was characterized by cyclic voltammetry, differential pulse voltammetry and scanning electron microscopy. Results: Under the selected optimal conditions, the molecularly imprinted sensor shows a linear range from 1.0 × 10-7 to 2.0 × 10-5 mol L-1 for SDM, with a detection limit of 4.0 × 10-8 mol L-1. The sensor was applied to the determination of SDM in aquaculture water samples successfully, with the recoveries ranging from 95% to 106%. Conclusion: The proposed sensor exhibited a high degree of selectivity for SDM in comparison to other structurally similar molecules, along with long-term stability, good reproducibility and excellent regeneration capacity. The sensor may offer a feasible strategy for the analysis of SDM in aquaculture water samples.

Differential Pulse Voltammetric Determination of Piroxicam on Lanthanide Ferric Oxide Nanoparticles-Carbon Paste Modified Electrode

2018 ◽  
Vol 14 (3) ◽  
pp. 271-276 ◽  
Author(s):  
Isaac Yves Lopes de Macedo ◽  
Morgana Fernandes Alecrim ◽  
Luane Ferreira Garcia ◽  
Aparecido Ribeiro de Souza ◽  
Wallans Torres Pio dos Santos ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Ferric Oxide ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Oxide Nanoparticles ◽  
Carbon Paste ◽  
Carbon Paste Modified Electrode

scholarly journals Effective replacement of cetyltrimethylammonium bromide (CTAB) by mercaptoalkanoic acids on gold nanorod (AuNR) surfaces in aqueous solutions

Nanoscale ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 658-668 ◽  
Author(s):  
Rafael del Caño ◽  
Jose M. Gisbert-González ◽  
Jose González-Rodríguez ◽  
Guadalupe Sánchez-Obrero ◽  
Rafael Madueño ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Gold Nanorods ◽  
Ligand Exchange ◽  
Cetyltrimethylammonium Bromide ◽  
Gold Nanorod ◽  
Experimental Conditions ◽  
Seed Mediated ◽  
The Stability

The highly packed cetyltrimethylammonium bromide bilayer on the surface of gold nanorods synthesized by the seed-mediated procedure hampers the complete ligand exchange under experimental conditions that preserves the stability of the dispersions.

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