scholarly journals Determination of Methyldopa and Paracetamol in Pharmaceutical Samples by a Low Cost Genipa americana L. Polyphenol Oxidase Based Biosensor

2019 ◽  
Vol 9 (3) ◽  
pp. 416-422
Author(s):  
Rafael Souza Antunes ◽  
Douglas Vieira Thomaz ◽  
Luane Ferreira Garcia ◽  
Eric de Souza Gil ◽  
Vernon Sydwill Sommerset ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Low Cost ◽  
Differential Pulse ◽  
Pharmaceutical Samples ◽  
Polyphenol Oxidases ◽  
Voltammetric Techniques ◽  
Relative Standard ◽  
Pulse Voltammetry ◽  
Phenolic Drugs

Purpose: Jenipapo fruit (Genipa americana L) is a natural source of polyphenol oxidases (PPOs) whose potential in pharmaceutical analysis is noteworthy. Henceforth, this work reports the electrochemical study of a low-cost PPO-based biosensor produced from the crude extract of Jenipapo fruits and accounts a practical approach to employ this biosensor in the determination of methyldopa and paracetamol in pharmaceutical samples. Methods: In order to investigate the electrochemical properties of the biosensor, theoretical and practical approaches were employed, and both samples and the biosensor were analyzed through electrochemical impedance spectroscopy (EIS) and voltammetric techniques, namely: differential pulse voltammetry (DPV) and cyclic voltammetry (CV). Results: showcased that the biosensor presented good analytical features, as well as low detection limits (8 μmol L-1 for methyldopa and 5 μmol L-1 for paracetamol). The relative standard deviation was less than 5% mid-assay. Conclusion: The use of this biosensor is a reliable, low cost and useful alternative in the pharmaceutic determination of phenolic drugs (e.g. methyldopa and paracetamol).

Graphene Modified Molecular Imprinting Electrochemical Sensor for Determining the Content of Dopamine

2019 ◽  
Vol 15 (6) ◽  
pp. 628-634
Author(s):  
Rong Liu ◽  
Jie Li ◽  
Tongsheng Zhong ◽  
Liping Long
Keyword(s):  
Electrochemical Sensor ◽  
Molecular Imprinting ◽  
Neurological Disorders ◽  
Room Temperature ◽  
Low Cost ◽  
Differential Pulse ◽  
Current Response ◽  
Specific Selectivity ◽  
Pulse Voltammetry

Background: The unnatural levels of dopamine (DA) result in serious neurological disorders such as Parkinson’s disease. Electrochemical methods which have the obvious advantages of simple operation and low-cost instrumentation were widely used for determination of DA. In order to improve the measurement performance of the electrochemical sensor, molecular imprinting technique and graphene have always been employed to increase the selectivity and sensitivity. Methods: An electrochemical sensor which has specific selectivity to (DA) was proposed based on the combination of a molecular imprinting polymer (MIP) with a graphene (GR) modified gold electrode. The performance and effect of MIP film were investigated by differential pulse voltammetry (DPV) and cyclic voltammetry (CV) in the solution of 5.0 ×10-3 mol/L K3[Fe(CN)6] and K4[Fe(CN)6] with 0.2 mol/L KCl at room temperature. Results: This fabricated sensor has well repeatability and stability, and was used to determine the dopamine of urine. Under the optimized experiment conditions, the current response of the imprinted sensor was linear to the concentration of dopamine in the range of 1.0×10-7 ~ 1.0×10-5 mol/L, the linear equation was I (µA) = 7.9824+2.7210lgc (mol/L) with the detection limit of 3.3×10-8 mol/L. Conclusion: In this work, a highly efficient sensor for determination of DA was prepared with good sensitivity by GR and great selectivity of high special recognization ability by molecular imprinting membrane. This proposed sensor was used to determine the dopamine in human urine successfully.

Electrochemical Detection of Fenthion Insecticide in Olive Oils by a Sensitive Non-Enzymatic Biomimetic Sensor Enhanced with Metal Nanoparticles

2021 ◽  
Vol 5 (1) ◽  
pp. 64
Author(s):  
Youssra Aghoutane ◽  
Nezha El Bari ◽  
Zoubida Laghrari ◽  
Benachir Bouchikhi
Keyword(s):  
Electrochemical Impedance ◽  
Differential Pulse ◽  
Organophosphate Insecticide ◽  
Imprinted Polymer ◽  
High Recovery ◽  
Molecularly Imprinted ◽  
Olive Oils ◽  
Pulse Voltammetry ◽  
Biomimetic Sensor

Fenthion, an organophosphate insecticide, is a cholinesterase inhibitor and is highly toxic. An electrochemical sensor based on molecularly imprinted polymer is developed here for its detection. For this purpose, 2-aminothiophenol mixed with gold nanoparticles was immobilized on screen-printed gold electrodes. The FEN pattern was then fixed before being covered with 2-aminothiophenol. Cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy methods were used for the electrochemical characterization. The low detection limit was 0.05 mg/Kg over a range of 0.01–17.3 µg/mL. The sensor was successfully applied for the determination of FEN in olive oil samples with high recovery values.

Simultaneous determination of Pb and Cd in low-cost jewelry using differential pulse voltammetry

2016 ◽  
Vol 8 (45) ◽  
pp. 8028-8032
Author(s):  
Taimara Polidoro Ferreira ◽  
Rafael Arromba de Sousa ◽  
Denise Lowinsohn
Keyword(s):  
Differential Pulse Voltammetry ◽  
Simultaneous Determination ◽  
Low Cost ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Pulse Voltammetry

The simultaneous electrochemical determination of lead (Pb) and cadmium (Cd) in low-cost jewelry was achieved using differential pulse voltammetry (DPV).

scholarly journals Electrochemical and analytical performance of boron-doped diamond electrode for determination of ascorbic acid

2017 ◽  
Vol 10 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Ivana Sálusová ◽  
Kristína Cinková ◽  
Barbora Brtková ◽  
Marian Vojs ◽  
Marián Marton ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Analytical Performance ◽  
Current Response ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
Relative Standard ◽  
Pulse Voltammetry

Abstract The electrochemical behavior and determination of ascorbic acid (AA) was investigated at a bare boron-doped diamond (BDD) electrode using cyclic and differential pulse voltammetry. The influence of pH of supporting electrolyte and scan rate on the current response of analyte was examined to select the suitable experimental conditions. It was found that AA provided one well-shaped irreversible and diffusioncontrolled oxidation peak at +0.87 V vs. Ag/AgCl in Britton-Robinson buffer pH 4.0. Applying differential pulse voltammetry, the peak current of AA was linearly proportional to its concentration from 5 × 10-6 to 2 × 10-4 mol L-1 (R2 = 0.999), with the limit of detection of 1.1 × 10-6 mol L-1 and the good repeatability (relative standard deviation of 2.3 %). The developed electroanalytical protocol was successfully applied to determine the content of AA in commercial pharmaceutical preparations, based on the standard additions method, with the obtained recovery of 122 %. The accomplished analytical performance indicates that BDD electrodes are promising electrochemical sensors for pharmaceutical analysis.

scholarly journals Nanostructured TiO2 Carbon Paste Based Sensor for Determination of Methyldopa

2018 ◽  
Vol 11 (4) ◽  
pp. 99
Author(s):  
Luane Ferreira Garcia ◽  
Carlos Eduardo Peixoto da Cunha ◽  
Emily Kussmaul Gonçalves Moreno ◽  
Douglas Vieira Thomaz ◽  
Germán Sanz Lobón ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
Pharmaceutical Formulations ◽  
Graphite Powder ◽  
Differential Pulse ◽  
Carbon Paste ◽  
X Ray Diffraction ◽  
Pharmaceutical Samples ◽  
Nanostructured Tio2

Methyldopa is a catecholamine widely used in the treatment of mild to moderate hypertension whose determination in pharmaceutical formulae is of upmost importance for dose precision. Henceforth, a low-cost carbon paste electrode (CPE) consisting of graphite powder obtained from a crushed pencil stick was herein modified with nanostructured TiO2 (TiO2@CPE) aiming for the detection of methyldopa in pharmaceutical samples. The TiO2-modified graphite powder was characterized by scanning electron microscopy and X-ray diffraction, which demonstrated the oxide nanostructured morphology. Results evidenced that sensitivity was nonetheless increased due to electro-catalytic effects promoted by metal modification, and linear response obtained by differential pulse voltammetry for the determination of methyldopa (pH = 5.0) was between 10–180 μmol/L (Limit of Detection = 1 μmol/L) with the TiO2@CPE sensor. Furthermore, the constructed sensor was successfully applied in the detection of methyldopa in pharmaceutical formulations and excipients promoted no interference, that indicates that the sensor herein developed is a cheap, reliable, and useful strategy to detect methyldopa in pharmaceutical samples, and may also be applicable in determinations of similar compounds.

scholarly journals Recycling Chocolate Aluminum Wrapping Foil as to Create Electrochemical Metal Strip Electrodes

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 21
Author(s):  
Hairul Hisham Hamzah ◽  
Nur Hidayah Saleh ◽  
Bhavik Anil Patel ◽  
Mohd Muzamir Mahat ◽  
Saiful Arifin Shafiee ◽  
...  
Keyword(s):  
Electrochemical Sensors ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Differential Pulse ◽  
Redox Species ◽  
X Ray ◽  
Conductive Materials ◽  
Electrode Surfaces ◽  
Electrical Conductivities ◽  
Pulse Voltammetry

The development of low-cost electrode devices from conductive materials has recently attracted considerable attention as a sustainable means to replace the existing commercially available electrodes. In this study, two different electrode surfaces (surfaces 1 and 2, denoted as S1 and S2) were fabricated from chocolate wrapping aluminum foils. Energy dispersive X-Ray (EDX) and field emission scanning electron microscopy (FESEM) were used to investigate the elemental composition and surface morphology of the prepared electrodes. Meanwhile, cyclic voltammetry (CV), chronoamperometry, electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV) were used to assess the electrical conductivities and the electrochemical activities of the prepared electrodes. It was found that the fabricated electrode strips, particularly the S1 electrode, showed good electrochemical responses and conductivity properties in phosphate buffer (PB) solutions. Interestingly, both of the electrodes can respond to the ruthenium hexamine (Ruhex) redox species. The fundamental results presented from this study indicate that this electrode material can be an inexpensive alternative for the electrode substrate. Overall, our findings indicate that electrodes made from chocolate wrapping materials have promise as electrochemical sensors and can be utilized in various applications.

Microelectrodes based on porphyrins for the determination of ascorbic acid in pharmaceutical samples and beverages

2012 ◽  
Vol 16 (07n08) ◽  
pp. 809-816 ◽  
Author(s):  
Raluca-Ioana Stefan-van Staden ◽  
Simona Cornelia Balasoiu ◽  
Jacobus Frederick van Staden ◽  
Gabriel-Lucian Radu
Keyword(s):  
Ascorbic Acid ◽  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Carbon Paste ◽  
Limits Of Detection ◽  
Pharmaceutical Samples ◽  
Pulse Voltammetry ◽  
Fresh Surface ◽  
Diamond Paste

Different porphyrins were used for the design of seven carbon paste and seven diamond paste based microelectrodes, which were employed for the determination of ascorbic acid in pharmaceutical and beverages samples using differential pulse voltammetry (DPV). The limits of detection lie between 1.1 × 10-14 and 5.1 × 10-7 M while the sensitivities were between 3.07 pA/M and 1285.18 A/M. Ascorbic acid was recovered reliable from pharmaceutical and beverages samples in percentages higher than 92.00% and 91.50%, respectively. The surface of the microelectrodes can easily be renewed by simple polishing, obtaining a fresh surface ready for use in a new assay.

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 Graphene Oxide Nanoparticles Modified Paper Electrode as a Biosensing Platform for Detection of the htrA Gene of O. tsutsugamushi

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4366
Author(s):  
Deepak Kala ◽  
Tarun Kumar Sharma ◽  
Shagun Gupta ◽  
Vivek Verma ◽  
Atul Thakur ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Properties ◽  
Differential Pulse Voltammetry ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Differential Pulse ◽  
Oxide Nanoparticles ◽  
Layer By Layer ◽  
Dna Sensor ◽  
Pulse Voltammetry

The unique structural and electrochemical properties of graphene oxide (GO) make it an ideal material for the fabrication of biosensing devices. Therefore, in the present study, graphene oxide nanoparticles modified paper electrodes were used as a low-cost matrix for the development of an amperometric DNA sensor. The graphene oxide was synthesized using the modified hummers method and drop cast on a screen-printed paper electrode (SPPE) to enhance its electrochemical properties. Further, the GO/SPPE electrode was modified with a 5′NH2 labeled ssDNA probe specific to the htrA gene of Orientia tsutsugamushi using carbodiimide cross-linking chemistry. The synthesized GO was characterized using UV-Vis, FTIR, and XRD. The layer-by-layer modification of the paper electrode was monitored via FE-SEM, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The sensor response after hybridization with single-stranded genomic DNA (ssGDNA) of O. tsutsugamushi was recorded using differential pulse voltammetry (DPV). Methylene blue (1 mM in PBS buffer, pH 7.2) was used as a hybridization indicator and [Fe(CN)6]−3/−4 (2.5 mM in PBS buffer, pH 7.2) as a redox probe during electrochemical measurements. The developed DNA sensor shows excellent sensitivity (1228.4 µA/cm2/ng) and LOD (20 pg/µL) for detection of O. tsutsugamushi GDNA using differential pulse voltammetry (DPV).

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