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

Author(s):  
Xiao-Yan Ma ◽  
Hong-Qiao Yang ◽  
Hua-Bing Xiong ◽  
Xiao-Fen Li ◽  
Jing-Ting Gao ◽  
...  

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.

2019 ◽  
Vol 9 (3) ◽  
pp. 187-195 ◽  
Author(s):  
Somayeh Tajik ◽  
Hadi Beitollahi ◽  
Mohammad Reza Aflatoonian

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.


Author(s):  
Sayed ali Ahmadi ◽  
Sayed Zia Mohammadi ◽  
Maedeh Jafari ◽  
Peyman Mohammadzadeh Jahani ◽  
Raana Mashayekh

The detection of tramadol using a screen printed electrode modified with La3+/ZnO nano-flowers and multi-walled carbon nanotubes (La3+/ZnO NFs-MWCNTs/SPE) is reported in this work. In order to examine tramadol electrochemical oxidation, the modified electrode was implemented with the utilization of differential pulse voltammetry, chronoamperometry and cyclic voltammetry as diagnostic techniques. The proposed electrode displays favorable electrocatalytic behavior concerning tramadol oxidation with an approximately 330 mV potential shift to a lesser positive potential. In the 0.5 to 800.0 μM range for tramadol, differential pulse voltammetry displays linear dynamic activity. Tramadol detection limit of 0.08 μM was derived within optimized testing conditions for this simple construction sensor. Lastly, this fabricated sensor was utilized with desirable results to determine tramadol in tramadol samples and urine samples.


Author(s):  
Hamid Sarhadi ◽  
Zare Maryam

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.


2020 ◽  
Vol 85 (4) ◽  
pp. 505-515
Author(s):  
Sayed Mohammadi ◽  
Hadi Beitollahi ◽  
Tahereh Rohani ◽  
Hossein Allahabadi ◽  
Somayeh Tajik

La2O3/Co3O4 nanocomposite was synthesized and then used for the modification of screen-printed electrode (SPE) prior to the electrochemical determination of sertraline. A significant increment in peak current response was observed and peak potential also shifted towards less positive potentials showing the facilitated oxidation procedure at surface of modified SPE (La2O3/ /Co3O4/SPE). The quantitative determination of sertraline was carried out by using different pulse voltammetry and the anodic peak current was found to increase with increasing sertraline concentration in the linear range of 5.0400.0 ?M with limit of detection as 1.0 ?M. The prepared La2O3/Co3O4/SPE has been successfully used for detecting sertraline in sertraline tablet and urine samples with excellent recoveries.


2016 ◽  
Vol 8 (5) ◽  
pp. 962-967 ◽  
Author(s):  
Shixin Wu ◽  
Nadia Chandra Sekar ◽  
Swee Ngin Tan ◽  
Hong Xie ◽  
Sum Huan Ng

Detection of trivalent chromium with screen printed electrodes modified by chitosan–gold nanocomposites using differential pulse voltammetry (DPSV), showing a linear range from 1 to 100 μM and a detection limit of 0.4 μM (based on 3σ).


1990 ◽  
Vol 55 (6) ◽  
pp. 1508-1517 ◽  
Author(s):  
Jiří Barek ◽  
Dagmar Civišová ◽  
Ashutosh Ghosh ◽  
Jiří Zima

The polarographic reduction of the title azo dye was studied and optimal conditions were found for its analytical utilization in the concentration range 1 . 10-6 - 1 . 10-7 mol l-1 using differential pulse polarography and 1 . 10-6 - 1 . 10-8 mol l-1 using fast scan differential pulse voltammetry or linear scan voltammetry at a hanging mercury drop electrode. When the latter technique is combined with adsorptive accumulation of the studied substance on the surface of the hanging mercury drop, the determination limit can be further decreased to 3 . 10-9 mol l-1.


2021 ◽  
Author(s):  
Yan Jin ◽  
Tong QI ◽  
Yuqing Ge ◽  
Jin Chen ◽  
Li juan Liang ◽  
...  

In this paper, ultrasensitive electrochemical determination of phosphate in water is achieved by hydrophilic TiO2 modified glassy carbon electrodes for the first time. Differential pulse voltammetry (DPV) method is proposed...


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