scholarly journals A novel dopamine electrochemical sensor based on La3+/ZnO nanoflower modified graphite screen printed electrode

2019 ◽  
Vol 9 (3) ◽  
pp. 187-195 ◽  
Author(s):  
Somayeh Tajik ◽  
Hadi Beitollahi ◽  
Mohammad Reza Aflatoonian
Keyword(s):  
Modified Electrode ◽  
Phosphate Buffer Solution ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Screen Printed Electrode ◽  
Buffer Solution ◽  
Optimized Conditions ◽  
Screen Printed

Flower-like La3+/ZnO nanocomposite was facile synthesized. A simple and ultrasensitive sensor based on graphite screen printed electrode (SPE) modified by La3+/ZnO nanoflower was developed for the electrochemical determination of dopamine. The electrochemical behavior of dopamine was studied in 0.1 M phosphate buffer solution (PBS) using cyclic voltammetry (CV), chronoamperometry (CA) and differential pulse voltammetry (DPV). Compared with the unmodified graphite screen printed electrode, the modified electrode facilitates the electron transfer of dopamine, since it notably increases the oxidation peak current of dopamine. Also, according to CV results the maximum oxidation of dopamine on La3+/ZnO/SPE occurs at 150 mV which is about 140 mV more negative compared with unmodified SPE. Under optimized conditions, the modified electrode exhibited a linear response over the concentration range from 0.15 to 300.0 μM, with a detection limit of 0.08 μM (S/N = 3). The proposed sensor exhibited a high sensitivity, good stability and was successfully applied for dopamine determination in dopamine ampoule, with high recovery.

scholarly journals Carvacrol electrochemical reaction characteristics on screen printed electrode modified with La2O3/Co3O4 nanocomposite

2019 ◽  
Vol 9 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Sayed Zia Mohammadi ◽  
Hadi Beitollahi ◽  
Tahereh Rohani ◽  
Hossein Allahabadi
Keyword(s):  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Differential Pulse ◽  
Co3o4 Nanoparticles ◽  
Electrochemical Characteristics ◽  
Screen Printed Electrode ◽  
Buffer Solution ◽  
Voltammetric Techniques ◽  
Screen Printed

Electrochemical characteristics of carvacrol were investigated on a screen-printed electrode (SPE) modified with La2O3/Co3O4 nanocomposite by using voltammetric techniques, which displayed a well-defined peak for sensitive carvacrol determination in phosphate buffer solution (PBS) at pH 7.0. La2O3/Co3O4 nanoparticles demonstrated suitable catalytic activity for carvacrol determination by differential pulse voltammetry (DPV) technique. Besides, determination of carvacrol in a real samples was recognized in the light of electrochemical findings and a validated voltammetric technique for quantitative analysis of carvacrol in a real formulation was proposed. The DPV peak currents were found to be linear in the concentration range of 10.0 to 800.0 μM. The limit of detection (LOD) was found to be 1.0 μM.

scholarly journals Electrochemical Polymerised Graphene Paste Electrode and Application to Catechol Sensing

2019 ◽  
Vol 13 (1) ◽  
pp. 81-87 ◽  
Author(s):  
Jamballi G. Manjunatha
Keyword(s):  
Modified Electrode ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Sample Pretreatment ◽  
Differential Pulse ◽  
Buffer Solution ◽  
Solution Ph ◽  
Graphene Paste Electrode ◽  
Paste Electrode

Objective: To build up an advantageous strategy for sensitive determination of catechol (CC), a poly (proline) modified graphene paste electrode (PPMGPE) was fabricated and used as a voltammetric sensor for the determination of CC. Methods: The performance of the modified electrode was studied using cyclic voltammetric (CV) and differential pulse voltammetric method (DPV). The modified electrode was characterized by CV and DPV. The surface of the modified electrode was examined by FESEM. The electrochemical behavior of CC in phosphate buffer solution (pH 7.5) was inspected using bare graphene paste electrode (BGPE) and PPMGPE. Results & Conclusion: The PPMGPE shows a lower limit of detection, calculated to be 8.7×10–7mol L−1 (S/N=3). This modified electrode was applied successfully for the determination of CC in water samples without applying any sample pretreatment.

scholarly journals Electrochemical sensor for determination of hydroxylamine using functionalized Fe3O4 nanoparticles and graphene oxide modified screen-printed electrode

2021 ◽  
Author(s):  
Hamed Tashakkorian ◽  
Behnaz Aflatoonian ◽  
Peyman Mohammadzadeh Jahani ◽  
Mohammad Reza Aflatoonian
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Fe3o4 Nanoparticles ◽  
Phosphate Buffer Solution ◽  
Electrochemical Process ◽  
Screen Printed Electrode ◽  
Buffer Solution ◽  
Solution Ph ◽  
Screen Printed

A simple strategy for determination of hydroxylamine based on Fe3O4 nanoparticles function­nalized by [2-(4-((3-(trimethoxysilyl)propylthio)methyl)1-H1,2,3-triazol-1-yl)acetic­acid] (FNPs) and graphene oxide (GO) modified screen-printed electrode (SPE), denoted as (Fe3O4 FNPs/GO/SPE), is reported. The electrochemical behavior of hydroxylamine was investigated at Fe3O4FNPs/GO/SPE by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chro­noamperometry (CHA) techniques in phosphate buffer solution (pH 7.0). Fe3O4 FNPs/GO/SPE as a novel electrochemical sensor exhibited catalytic activity toward the oxidation of hydroxyl­ami­ne. The potential of hydroxylamine oxidation was shifted to more negative potentials, and its oxidation peak current increased on the modified electrode, also indicating that under these conditions, the electrochemical process is irreversible. The electrocatalytic current of hydroxyl­amine showed a good relationship in the concentration range of 0.05–700.0 μM, with a detection limit of 10.0 nM. The proposed electrode was applied for the determination of hydroxyl­amine in water samples, too.

Electrochemical Determination of Norepinephrine at Poly (p-aminobenzenesulfonic Acid) Modified Sensor

2020 ◽  
Vol 16 (5) ◽  
pp. 591-600
Author(s):  
Şevket Zişan Yağcı ◽  
Ebru Kuyumcu Savan ◽  
Gamze Erdoğdu
Keyword(s):  
Ascorbic Acid ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Buffer Solution ◽  
Oxidation Current ◽  
Pulse Voltammetry ◽  
Modified Sensor

Objective: In this study, it was aimed to prepare an electrochemical sensor capable of assigning Norepinephrine in the presence of an interference such as ascorbic acid. Methods: A sensitive modified sensor was prepared by electrodeposition of p-aminobenzenesulfonic acid (p-ABSA) to the glassy carbon electrode by cyclic voltammetry. The electrooxidation of Norepinephrine was accomplished by cyclic and differential pulse voltammetry. Results: The current values were enhanced and the peak potentials of Norepinephrine and ascorbic acid were separated at the sensor compared to the bare electrode. There was linearity between the oxidation current and concentration of Norepinephrine ranging from 0.5 to 99.8 μM in phosphate buffer solution at pH 7.0. The limit of detection was 10.0 nM and the sensitivity was 0.455 μA/μM. Conclusion: The determination of Norepinephrine was successfully performed in real samples such as blood serum and urine at the poly (p-ABSA) sensor. To the best of our knowledge, this is the first study to detect Norepinephrine in the presence of ascorbic acid at poly (p-ABSA) modified sensor in the literature.

scholarly journals Electrochemical Behavior and Determination of Chlorogenic Acid Based on Carbon Nanotubes Modified Screen-Printed Electrode

2016 ◽  
Author(s):  
Xiao-Yan Ma ◽  
Hong-Qiao Yang ◽  
Hua-Bing Xiong ◽  
Xiao-Fen Li ◽  
Jing-Ting Gao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Optimal Conditions ◽  
Linear Regression Equation ◽  
Screen Printed Electrode ◽  
Redox Peak ◽  
Pulse Voltammetry ◽  
Screen Printed

In this paper, carbon nanotubes modified screen-printed electrode (CNTs/SPE) was prepared and the CNTs/SPE was employed for the electrochemical determination of antioxidant substance Chlorogenic acids (CGAs). A pair of well-defined redox peak of CGA was observed at the CNTs/SPE in 0.10 mol∙L-1 acetic acid-sodium acetate buffer (pH 6.2) and electrode process is adsorption-controlled. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) method for the determination of CGA were proposed based on the CNTs/SPE. Under the optimal conditions, the proposed method exhibited linear ranges from 4.73×10-7 to 4.45×10-5 mol∙L-1, the linear regression equation was Ipa(µA) = 4.1993 C (mol∙L-1)+1.1039 (r = 0.9976) and the detection limit for CGA could reach 3.25×10-6 mol∙L-1. The recovery of matrine was 94.74~106.65% (RSD = 2.92%) in coffe beans. The proposed method is quick, sensitive, reliable, and can be used for the determination of CGA.

scholarly journals A novel vitamin B9 sensor based on modified screen-printed electrode

2020 ◽  
Author(s):  
Hamid Sarhadi ◽  
Zare Maryam
Keyword(s):  
High Stability ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Current Response ◽  
Oxidation Peak ◽  
Screen Printed Electrode ◽  
Vitamin B9 ◽  
Pulse Voltammetry ◽  
Screen Printed

In the field of determination of vitamin B9 (folic acid, FA), we have described the development of a sensitive electrochemical sensor through promoting the screen-printed electrode (SPE) and taking the advantage of zinc ferrite magnetic nanoparticles (ZnFe2O4MNPs). Cyclic voltammetry (CV) experiments demonstrated the powerful activity of ZnFe2O4MNPs/SPE for electrooxidation of FA by showing the prominent oxidation peak at 600 mV vs. Ag/AgCl. By differential pulse voltammetry (DPV) measurements, a linear relation between current response and concentration of vitamin B9 was determined in the range of 1.0–100.0 µM, and detection limit is found to be 0.3 µM (S/N=3). Except high sensitivity, the developed sensor demonstrated high stability, reproducibility and repeatability, and was also successfully applied to specify FA in real samples of vitamin B9 tablets and human urine.

Electrochemical Determination of Uric Acid at CdTe Quantum Dot Modified Glassy Carbon Electrodes

2015 ◽  
Vol 98 (5) ◽  
pp. 1260-1266 ◽  
Author(s):  
Deng Pan ◽  
Shengzhong Rong ◽  
Guangteng Zhang ◽  
Yannan Zhang ◽  
Qiang Zhou ◽  
...  
Keyword(s):  
Uric Acid ◽  
Quantum Dot ◽  
Glassy Carbon ◽  
Semiconductor Nanocrystals ◽  
Phosphate Buffer Solution ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Buffer Solution ◽  
Peak Current ◽  
Cdte Quantum Dot

Abstract Cyclic voltammetry and differential pulse voltammetry were used to investigate the electrochemical behavior of uric acid (UA) at a CdTe quantum dot (QD) modified the glassy carbon electrode (GCE). CdTe QDs, as new semiconductor nanocrystals, can greatly improve the peak current of UA. The anodic peak current of UA was linear with its concentration between 1.0 × 10–6 and 4.0 × 10–4 M in 0.1 M pH 5.0 phosphate buffer solution. The LOD for UA at the CdTe electrode (1.0 × 10–7 M) was superior to that of the GCE. In addition, we also determined the effects of scan rate, pH, and interferences of UA for the voltammetric behavior and detection. The results indicated that modified electrode possessed excellent reproducibility and stability. Finally, a new and efficient electrochemical sensor for detecting UA was developed.

Fabrication of Graphene/Carbon Nanotube Composite Modified Electrode for Selective and Sensitive Determination of Uric Acid

2013 ◽  
Vol 641-642 ◽  
pp. 562-565
Author(s):  
Zheng Xiao Liu ◽  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Uric Acid ◽  
Carbon Nanotube ◽  
Modified Electrode ◽  
Phosphate Buffer Solution ◽  
Carbon Electrode ◽  
Buffer Solution ◽  
Sensitive Determination ◽  
Carbon Nanotube Composite

A novel composite was firstly synthesized by compositing graphenes (G) and carbon nanotubes (CNTs) and then a new composite modified electrode (G/CNTs/GCE) was prepared by coating the resulting composite on the surface of the glassy carbon electrode (GCE). The composite modified electrode G/CNTs/GCE showed great electrochemical activities which were studied by sensitive determining the electrochemistry behaviors of uric acid (UA). It revealed when the concentration range of UA changed from 1×10-7 mol/L to 1×10-3 mol/L, the peak currents had linear relationship with the concentration of UA in the phosphate buffer solution (PBS) which the value of pH is 7.0. And the linear equation is ip (μA) = 21.55C+28.94 (C: mmol/L), with the related coefficient 0.9964.

scholarly journals Carbon ceramic electrode incorporated with zeolite ZSM-5 for determination of Piroxicam

2010 ◽  
Vol 8 (1) ◽  
pp. 155-162 ◽  
Author(s):  
Karim Asadpour-Zeynali ◽  
Mir Majidi ◽  
Mitra Zarifi
Keyword(s):  
Modified Electrode ◽  
Pharmaceutical Formulations ◽  
Differential Pulse ◽  
Solution Ph ◽  
Carbon Ceramic Electrode ◽  
Experimental Parameters ◽  
Voltammetric Behavior ◽  
Carbon Ceramic ◽  
Optimized Conditions

AbstractA new chemically modified electrode is constructed based on carbon ceramic electrode incorporated with zeolite ZSM-5. Voltammetric behavior of piroxicam at the carbon ceramic zeolite modified electrode (CCZME) was investigated. The modified electrode exhibited catalytic activity toward the electrooxidation of piroxicam. Experimental parameters such as solution pH, scan rate, concentration of piroxicam and zeolite amount were studied. It has been shown that using the CCZME, piroxicam can be determined by differential pulse voltammetry (DPV) and hydrodynamic amperometry (HA). Under the optimized conditions the calibration plots are linear in the concentration ranges of 0.20–25.00 and 0.20–50.10 μM with limit of detections of 0.65 and 0.29 μM for DPV and HA, respectively. The modified electrode with DPV and HA methods was successfully applied for analysis of piroxicam in pharmaceutical formulations. The results were favorably compared to those obtained by the spiked method. The results of the analysis suggest that the proposed method has promise for the routine determination of piroxicam in the products examined.

Sensitive Determination of Epinephrine in the Presence of Ascorbic Acid at Poly(diphenylamine sulfonic acid) Modified Sensor

2020 ◽  
Vol 18 (4) ◽  
pp. 253-258
Author(s):  
Gamze Erdoğdu
Keyword(s):  
Ascorbic Acid ◽  
Sulfonic Acid ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Differential Pulse ◽  
Buffer Solution ◽  
Sensitive Determination ◽  
Pulse Voltammetry ◽  
Modified Sensor

A sensitive and simple modified sensor was prepared by electrodeposition of diphenylamine sulfonic acid (DPSA) to the glassy carbon electrode surface by cyclic voltammetry (CV) technique. The electrooxidation of epinephrine (EP) was accomplished by CV and differential pulse voltammetry at poly(DPSA) modified sensor. As a result of the findings, the current values were enhanced and both substances were separated at the modified sensor compared to the bare electrode. There was linearly between the oxidation current and concentration of EP from 0.2 to 100 μM in phosphate buffer solution at pH 7.0. The limit of detection was 5.0 nM and the sensitivity was 0.4205 μA/μM. The determination of EP was successfully and satisfactorily carried out in real samples such as human blood serum and urine at the poly(DPSA) sensor. To the best knowledge of this work, this is the first study that detect the EP in the presence of ascorbic acid at poly(DPSA) sensor in the literature.

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