scholarly journals Development of a Method for a Sensitive Simultaneous Determination of Dopamine and Paracetamol in Biological Samples and Pharmaceutical Preparations

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Ali Babaei ◽  
Aliyeh Dehdashti ◽  
Mohammad Afrasiabi
Keyword(s):  
Detection Limit ◽  
Modified Electrode ◽  
Pharmaceutical Preparation ◽  
Pharmaceutical Preparations ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Linear Range ◽  
Multiwalled Carbon ◽  
Excellent Stability

A chemically modified electrode is constructed based on multiwalled carbon nanotube—modified glassy carbon electrode (MWCNTs/GCE). The measurements were carried out by application of differential pulse voltammetry (DPV), cyclic voltammetry (CV), and chronoamperometry (CA) methods. Application of DPV method showed wide linear range of DA from 1 μM to 540 μM and a detection limit of 0.098 μM (S/N=3). The linear range of PAR of 3 μM to 300 μM and a detection limit of 0.15 μM, were obtained. The modified electrode showed electrochemical responses with high sensitivity, high selectivity, and excellent stability for DA and PAR determination at optimal conditions, which makes it a suitable sensor for simultaneous submicromolar detection of DA and PAR in solutions. The analytical performance of this sensor has been evaluated for detection of DA and PAR in human serum, human urine, and pharmaceutical preparation with satisfactory results.

Highly Sensitive Determination of Dopamine Using Osmium/Nafion Modified Disposable Integrated Biosensor

2009 ◽  
Vol 60-61 ◽  
pp. 311-314 ◽  
Author(s):  
Chun Xiu Liu ◽  
Hong Min Liu ◽  
Qing De Yang ◽  
Nan Sen Lin ◽  
Yi Lin Song ◽  
...  
Keyword(s):  
Detection Limit ◽  
Correlation Coefficient ◽  
Gold Electrode ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Redox Polymer ◽  
Highly Sensitive ◽  
Sensitive Determination ◽  
Excellent Reproducibility

A biosensor based on gold electrode modified by Pt nanaoparticles/Osmium redox polymer/Nafion trilayer film was fabricated and used for selective and sensitive determination of dopamine. The biosensor is explored for DA sensing using the cyclic voltammetry (CV), amperometric and differential pulse voltammetric (DPV) methods. The CV anodic peak currents showed a linear range with a correlation coefficient of 0.996, localized in the concentration range 0~192 μM. The differential pulse voltammetric (DPV) peak currents were linear with DA concentration during 2~425 μM with correlation coefficient of 0.99. The biosensor showed high sensitivity of 0.5 nA /nM cm2 and excellent reproducibility with the detection limit of ~10 nM (S/N=3) for the determination of DA. The easy fabrication, low detection limit and high sensitivity of the integrated biosensor making it particularly suitable for the analytical purposes.

scholarly journals Fabrication of Efficient and Selective Modified Graphene Paste Sensor for the Determination of Catechol and Hydroquinone

Surfaces ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 473-483
Author(s):  
Jamballi G. Manjunatha
Keyword(s):  
Modified Electrode ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Official Method ◽  
Limit Of Quantification ◽  
Selective Determination ◽  
Graphene Paste Electrode ◽  
Modified Graphene ◽  
Paste Electrode

An electrochemical sensor, based on a graphene paste electrode (GPE), was modified with a polymerization method, and the electrochemical behavior of catechol (CC) and hydroquinone (HQ) was investigated using electroanalytical methods like cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The effect of CC at the modified electrode was evidenced by the positive shift of the oxidation peak potential of CC at the poly (rosaniline)-modified graphene paste electrode (PRAMGPE) and the nine-fold enhancement of the peak current, as compared to a bare graphene paste electrode (BGPE). The sensitivity of CC investigated by DPV was more sensitive than CV for the analysis of CC. The DPV method showed the two linear ranges of 2.0 × 10−6–1.0 × 10−5 M and 1.5 × 10−5–5 × 10−5 M. The detection limit and limit of quantification were determined to be 8.2 × 10−7 and 27.6 × 10−7 M, respectively. The obtained results were compared successfully with respect to those obtained using the official method. Moreover, this sensor is applied for the selective determination of CC in the presence of HQ. The high sensitivity, good reproducibility, and wide linear range make the modified electrode suitable for the determination of CC in real samples. The practical application of the sensor was demonstrated by determining the concentration of CC in water samples with acceptable recoveries (97.5–98%).

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 Enzymatic Electroanalytical Biosensor Based on Maramiellus colocasiae Fungus for Detection of Phytomarkers in Infusions and Green Tea Kombucha

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 91
Author(s):  
Érica A. Batista ◽  
Giovanna N. M. Silva ◽  
Livia F. Sgobbi ◽  
Fabio B. Machado ◽  
Isaac Y. Macedo ◽  
...  
Keyword(s):  
Detection Limit ◽  
Gallic Acid ◽  
Green Tea ◽  
High Performance ◽  
Differential Pulse ◽  
Linear Range ◽  
Crude Enzyme Extract ◽  
Quantification Limit ◽  
The City

In this work, we developed an enzymatic voltammetric biosensor for the determination of catechin and gallic acid in green tea and kombucha samples. The differential pulse voltammetry (DPV) methodology was optimized regarding the amount of crude enzyme extract, incubation time in the presence of the substrates, optimal pH, reuse of the biosensor, and storage time. Samples of green tea and kombucha were purchased in local markets in the city of Goiânia-GO, Brazil. High performance liquid chromatography (HPLC) and Folin-Ciocalteu spectrophotometric techniques were performed for the comparison of the analytical methods employed. In addition, two calibration curves were made, one for catechin with a linear range from 1 to 60 µM (I = −0.152 * (catechin) − 1.846), with a detection limit of 0.12 µM and a quantification limit of 0.38 µM and one for gallic acid with a linear range from 3 to 60 µM (I = −0.0415 * (gallic acid) − 0.0572), with a detection limit of 0.14 µM and a quantification limit of 0.42 µM. The proposed biosensor was efficient in the determination of phenolic compounds in green tea.

scholarly journals Simultaneous Voltammetric Determination of Ascorbic Acid, Paracetamol, and Caffeine Using Electrochemically Reduced Graphene-Oxide-Modified Electrode

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Nguyen Hai Phong ◽  
Tran Thanh Tam Toan ◽  
Mai Xuan Tinh ◽  
Tran Ngoc Tuyen ◽  
Tran Xuan Mau ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Modified Electrode ◽  
Anodic Stripping Voltammetry ◽  
Pharmaceutical Preparations ◽  
Differential Pulse ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide

In the present paper, graphene oxide was directly electrodeposited by means of cyclic voltammetric techniques on the glassy-carbon electrode (GCE) to obtain a reduced graphene-oxide-modified electrode (ErGO/GCE). Cyclic voltammetry (CV) and differential pulse anodic stripping voltammetry (DP-ASV) had been utilized to study the electrochemical behavior of ErGO/GCE toward ascorbic acid (AA), paracetamol (PA), and caffeine (CA). Differential pulse voltammetry results show that AA, PA, and CA could be detected selectively and sensitively on ErGO/GCE with peak-to-peak separation of 312 mV and 756 mV for AA–PA and PA–CA, respectively. The factors affecting the voltammetric signals such as pH, scan rate, and interferents were addressed. The results reveal that the ErGO/GCE-modified electrode exhibits excellent electrochemical activity in the oxidation of PA, CA, and AA. The detection limits are 0.36 μM, 0.25 μM, and 0.23 μM for AA, PA and CA, respectively, suggesting that the ErGO/GCE can be utilized with high sensitivity and selectivity for the simultaneous determination of these compounds. Finally, the proposed method was successfully used to determine AA, PA, and CA in pharmaceutical preparations.

scholarly journals Development of a Carbon Paste Electrode Containing Benzo-15-Crown-5 for Trace Determination of the Uranyl Ion by Using a Voltammetric Technique

2009 ◽  
Vol 92 (1) ◽  
pp. 241-247 ◽  
Author(s):  
Sunil K Agrahari ◽  
Sangita D Kumar ◽  
Ashwini K Srivastava
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Modified Electrode ◽  
Carbon Paste Electrode ◽  
Electrochemical Impedance ◽  
Differential Pulse ◽  
Carbon Paste ◽  
Pulse Voltammetry ◽  
Paste Electrode

Abstract The interaction of macrocyclic compounds like crown ethers and UO22+ has been studied by electrochemical methods. A modified carbon paste electrode incorporating benzo-15-crown-5 (B15C5) was used to evaluate the electron transfer reaction of UO22+ by cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. Electrochemical impedance studies showed that charge transfer resistance was less for the B15C5-modified electrode than for the plain carbon paste electrode (PCPE). On the basis of these observations, a UO22+-sensitive crown ether chemically modified electrode (CME) for trace analysis was fabricated and investigated in aqueous solutions. It was found that a 5 B15C5CME for UO22+ showed a better voltammetric response than did the PCPE. UO22+ could be quantified at sub-μg/mL levels by differential pulse voltammetry with a detection limit of 0.03 μg/mL. By differential pulse adsorptive stripping voltammetry, UO22+ could be quantified in the working range of 0.002-0.2 μg/mL, with a detection limit of 1.1 μg/L. Simultaneous determination of UO22+, Pb2+, and Cd2+ was possible. The method was successfully applied to the determination of UO22+ in synthetic, as well as real, samples; the results were found to be comparable to those obtained by inductively coupled plasma-atomic emission spectroscopy.

scholarly journals Differential pulse voltammetric determination of diclofenac in pharmaceutical preparations and human serum

2015 ◽  
Vol 51 (2) ◽  
pp. 285-294 ◽  
Author(s):  
Bilal Yilmaz ◽  
Selcuk Kaban ◽  
Bilge Kagan Akcay ◽  
Ulvihan Ciltas
Keyword(s):  
Human Serum ◽  
Supporting Electrolyte ◽  
Pharmaceutical Preparation ◽  
Pharmaceutical Preparations ◽  
Differential Pulse ◽  
Acetonitrile Solution ◽  
Serum Samples ◽  
Electro Oxidation ◽  
Endogenous Substances

<p>This article describes a differential pulse voltammetric (DPV) method for the determination of diclofenac in pharmaceutical preparations and human serum. The proposed method was based on electro-oxidation of diclofenac at platinum electrode in 0.1 M TBAClO<sub>4</sub>/acetonitrile solution. The well-defined two oxidation peaks were observed at 0.87 and 1.27 V, respectively. Calibration curves that obtained by using current values measured for second peak were linear over the concentration range of 1.5-17.5 μg mL<sup>-1</sup>and 2-20 μg mL<sup>-1</sup> in supporting electrolyte and serum, respectively. Precision and accuracy were also checked in all media. Intra- and inter-day precision values for diclofenac were less than 3.87, and accuracy (relative error) was better than 4.12%. The method developed in this study is accurate, precise and can be easily applied to Diclomec, Dicloflam and Voltaren tablets as pharmaceutical preparation. In addition, the proposed technique was successfully applied to spiked human serum samples. No electro-active interferences from the endogenous substances were found in human serum.</p>

Self-Assembled Graphene for Determination of Catechol in Wastewater at Modified Glassy Carbon Electrode

2012 ◽  
Vol 161 ◽  
pp. 255-259 ◽  
Author(s):  
Mei Feng Chen ◽  
Xin Ying Ma ◽  
Xia Li
Keyword(s):  
Cyclic Voltammetry ◽  
Detection Limit ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
High Sensitivity ◽  
Carbon Electrode ◽  
Oxidation Peak ◽  
Modified Glassy Carbon Electrode

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.

scholarly journals Determination of Etofibrate, Fenofibrate, and Atorvastatin in Pharmaceutical Preparations and Plasma Using Differential Pulse Polarographic and Square Wave Voltammetric Techniques

2008 ◽  
Vol 91 (5) ◽  
pp. 1051-1058 ◽  
Author(s):  
Mohamed A Korany ◽  
Ismail I Hewala ◽  
Karim M Abdel-Hay
Keyword(s):  
Reference Electrode ◽  
Pharmaceutical Preparations ◽  
High Sensitivity ◽  
Pulse Amplitude ◽  
Differential Pulse ◽  
Square Wave ◽  
Voltammetric Techniques ◽  
Irreversible Reduction ◽  
Relative Standard

Abstract Etofibrate, fenofibrate, and atorvastatin were determined in their pharmaceutical preparations and human plasma using differential pulse polarographic and square wave voltammetric techniques by reduction at a dropping-mercury working electrode versus Ag/AgCl reference electrode. The reversibility of the electrode reactions was tested using cyclic voltammetry, and they were found to be irreversible reduction reactions. Optimum conditions such as pH, scan rate, and pulse amplitude were studied, and validation of the proposed methods was performed. The proposed methods proved to be accurate, precise, robust, and specific for determination of the 3 drugs. The relative standard deviation values were &lt;2, indicating that these methods are precise. Limits of detection and quantitation were in the ranges of 0.0370.21 and 0.120.71 g/mL, respectively, indicating high sensitivity.

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