scholarly journals Convenient Heme Nanorod Modified Electrode for Quercetin Sensing by Two Common Electrochemical Methods

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1519
Author(s):  
Jin-Guang Liu ◽  
Jia-Zheng Wan ◽  
Qing-Min Lin ◽  
Guo-Cheng Han ◽  
Xiao-Zhen Feng ◽  
...  
Keyword(s):  
Detection Limit ◽  
Electrochemical Impedance ◽  
Differential Pulse ◽  
Human Diet ◽  
Leaf Powder ◽  
Pulse Voltammetry ◽  
High Concentrations ◽  
Optimized Conditions ◽  
Powder Extract ◽  
Linear Concentration

Quercetin (Qu) is one of the most abundant flavonoids in the human diet. High concentrations of Qu can easily cause adverse effects and induce inflammation, joint pain and stiffness. In this study, Heme was used as a sensitive element and deposited and formed nanorods on a glassy carbon electrode (GCE) for the detection of Qu. The Heme/GCE sensor was characterized using scanning electron microscopy (SEM), cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques. Under optimized conditions, the developed sensor presented a linear concentration ranging from 0.1 to 700 μmol·L−1 according to the CV and DPV methods. The detection limit for the sensor was 0.134 μmol·L−1 and its sensitivity was 0.12 μA·μM−1·cm−2, which were obtained from CV analysis. Through DPV analysis we obtained a detection limit of 0.063 μmol·L−1 and a sensitivity of 0.09 μA·μM−1·cm−2. Finally, this sensor was used to detect the Qu concentration in loquat leaf powder extract, with recovery between 98.55–102.89% and total R.S.D. lower than 3.70%. The constructed electrochemical sensor showed good anti-interference, repeatability and stability, indicating that it is also usable for the rapid detection of Qu in actual samples.

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 Teknik Differential Pulse Voltammetry Menggunakan Elektroda Pasta Karbon Termodifikasi Fe2O3 untuk Penentuan Kadar Fe(III) dalam Air Laut di Pelabuhan Benoa Bali

2021 ◽  
Vol 17 (1) ◽  
pp. 54
Author(s):  
Irdhawati Irdhawati ◽  
Ni Putu Antari Dewi ◽  
Ida Ayu Gede Widihati
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Carbon Paste ◽  
The West ◽  
Quantitation Limit ◽  
Passenger Ships ◽  
Scan Rate ◽  
Pulse Voltammetry ◽  
Linear Concentration

<p>Pelabuhan Benoa merupakan salah satu pelabuhan di Provinsi Bali tempat berlabuhnya kapal/perahu nelayan, kapal penumpang, dan kapal untuk pariwisata. Aktivitas masyarakat di sekitar pelabuhan dapat menjadi sumber pencemar logam berat. Penelitian ini bertujuan untuk mengetahui hasil optimasi dan validasi elektroda pasta karbon tanpa modifikasi (EPK) dan EPK termodifikasi Fe<sub>2</sub>O<sub>3</sub> (EPK Fe<sub>2</sub>O<sub>3</sub>) dengan teknik <em>differential pulse voltammetry</em> (DPV) untuk pengukuran Fe(III) dalam sampel air laut di Pelabuhan Benoa. Parameter yang dioptimasi yaitu laju pindai dan komposisi Fe<sub>2</sub>O<sub>3</sub> dalam pasta karbon. Selanjutnya dilakukan validasi pengukuran, meliputi rentang konsentrasi linier, limit deteksi, limit kuantisasi, keberulangan, dan persen perolehan kembali. Hasil yang diperoleh yaitu laju pindai optimum 15 mV/s menggunakan EPK, menjadi<ins cite="mailto:Microsoft%20Office%20User" datetime="2021-02-27T20:39"> </ins>lebih cepat yaitu 20 mV/s menggunakan EPK Fe<sub>2</sub>O<sub>3</sub>. Komposisi <em>modifier</em> terbaik dalam pasta karbon sebesar 0,5%. Rentang konsentrasi linier pengukuran menggunakan EPK yaitu 5 ~ 100 mg/L menjadi 5 ~ 2000 mg/L pada EPK Fe<sub>2</sub>O<sub>3. </sub>Limit deteksi dan limit kuantisasi menggunakan EPK Fe<sub>2</sub>O<sub>3 </sub>masing-masing 0,5490 mg/L dan 0,5497 mg/L, lebih rendah daripada menggunakan EPK yaitu 1,0667 mg/L dan 1,0688 mg/L. Keberulangan pengukuran menghasilkan rasio Horwitz yang lebih kecil dari dua. Nilai persen perolehan kembali pengukuran larutan standar dengan matriks larutan sampel yang diambil pada tiga lokasi yang berbeda, yaitu pada Dermaga Barat 97,51±9,92% ; Dermaga Selatan 101,18±10,60%; dan Dermaga Timur 95,50±1,23%. Hasil pengukuran Fe(III) dalam sampel diperoleh 129,98±13,65 mg/L; 114,85±13,75 mg/L; dan 127,77±4,01 mg/L, masing-masing pada Dermaga Barat, Selatan, dan Timur.</p><p><strong>Differential Pulse Voltammetry Technique Using Fe<sub>2</sub>O<sub>3</sub> Modified Carbon Paste Electrode for Determination of Fe(III) Levels in Seawater at Benoa Harbor Bali. </strong>Benoa Port is one of the ports in the Province of Bali where fishing boats, passenger ships, and ships for tourism are anchored. Activities around the port can be a source of heavy metal pollutants. This study aims to optimize and validates carbon paste electrodes without modification (EPK) and modified by Fe<sub>2</sub>O<sub>3</sub> (EPK Fe<sub>2</sub>O<sub>3</sub>) using differential pulse voltammetry (DPV) techniques for Fe (III) measurements in seawater at Benoa Harbor. The optimized parameters were scan rate and the Fe<sub>2</sub>O<sub>3</sub> composition in carbon paste. Meanwhile, the validation was performed, including the range of linear concentration, detection limit, quantitation limit, repeatability, and percent of the recovery. The research found that the optimum scan rate was 15 mV/s using EPK, become faster to 20 mV/s using EPK Fe<sub>2</sub>O<sub>3</sub>. The optimum <em>modifier</em> composition in carbon paste was 0.5%. The linear concentration range of measurement using EPK was 5 ~ 100 mg/L to 5 ~ 2000 mg/L at EPK Fe<sub>2</sub>O<sub>3</sub>. The detection limit and the quantitation limit using EPK Fe<sub>2</sub>O<sub>3</sub> were 0.5490 mg/L and 0.5497 mg/L, respectively. Those are lower than the detection limit quantitation by EPK i.e., 1.0667 mg/L and 1.0688 mg/L, respectively. Repeated measurements produce a Horwitz ratio which is less than two. The percent of recovery value of the measurement of the standard solution with the sample solution matrix taken from the three different locations are 97.51±9.92% for the West Pier region; 101.18±10.60% for the South Pier region; and 95.50±1.23% for the East Pier region. The Fe(III) measurements to the different samples from the West Pier, South Pier, and East Pier regions were 129.98±13.65 mg/L; 114.85±13.75 mg/L; and 127.77±4.01 mg/L, respectively.</p>

Polarographic and voltammetric determination of 6-mercaptopurine and 6-thioguanine

1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Detection Limits ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Pulse Voltammetry

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.

scholarly journals Electrochemical Investigation of Curcumin–DNA Interaction by Using Hydroxyapatite Nanoparticles–Ionic Liquids Based Composite Electrodes

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4344
Author(s):  
Merve Uca ◽  
Ece Eksin ◽  
Yasemin Erac ◽  
Arzum Erdem
Keyword(s):  
Electrochemical Impedance ◽  
Differential Pulse ◽  
Dna Interaction ◽  
Composite Electrodes ◽  
Hydroxyapatite Nanoparticles ◽  
Graphite Electrodes ◽  
X Ray ◽  
Pulse Voltammetry ◽  
Polymerase Chain

Hydroxyapatite nanoparticles (HaP) and ionic liquid (IL) modified pencil graphite electrodes (PGEs) are newly developed in this assay. Electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and cyclic voltammetry (CV) were applied to examine the microscopic and electrochemical characterization of HaP and IL-modified biosensors. The interaction of curcumin with nucleic acids and polymerase chain reaction (PCR) samples was investigated by measuring the changes at the oxidation signals of both curcumin and guanine by differential pulse voltammetry (DPV) technique. The optimization of curcumin concentration, DNA concentration, and the interaction time was performed. The interaction of curcumin with PCR samples was also investigated by gel electrophoresis.

scholarly journals Supramolecular assemblies of carbon nanocoils and tetraphenylporphyrin derivatives for sensing of catechol and hydroquinone in aqueous solution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Syeda Aqsa Batool Bukhari ◽  
Habib Nasir ◽  
Lujun Pan ◽  
Mehroz Tasawar ◽  
Manzar Sohail ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Linear Trend ◽  
Differential Pulse ◽  
Peak Potential ◽  
Limit Of Quantification ◽  
Efficient Detection ◽  
Good Repeatability ◽  
Ft Ir ◽  
Pulse Voltammetry

AbstractNon-enzymatic electrochemical detection of catechol (CC) and hydroquinone (HQ), the xenobiotic pollutants, was carried out at the surface of novel carbon nanocoils/zinc-tetraphenylporphyrin (CNCs/Zn-TPP) nanocomposite supported on glassy carbon electrode. The synergistic effect of chemoresponsive activity of Zn-TPP and a large surface area and electron transfer ability of CNCs lead to efficient detection of CC and HQ. The nanocomposite was characterized by using FT-IR, UV/vis. spectrophotometer, SEM and energy dispersive X-ray spectroscopy (EDS). Cyclic voltammetry, differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy were used for the electrochemical studies. CNCs/Zn-TPP/GCE nanosensor displayed a limit of detection (LOD), limit of quantification (LOQ) and sensitivity for catechol as 0.9 µM, 3.1 µM and 0.48 µA µM−1 cm−2, respectively in a concentration range of 25–1500 µM. Similarly, a linear trend in the concentration of hydroquinone detection was observed between 25 and 1500 µM with an LOD, LOQ and sensitivity of 1.5 µM, 5.1 µM and 0.35 µA µM−1 cm−2, respectively. DPV of binary mixture pictured well resolved peaks with anodic peak potential difference, ∆Epa(CC-HQ), of 110 mV showing efficient sensing of CC and HQ. The developed nanosensor exhibits stability for up to 30 days, better selectivity and good repeatability for eight measurements (4.5% for CC and 5.4% for HQ).

scholarly journals Selective Determination of Iron(III) in Sea Water by Gold Nanoparticles Self-assembled with N-carboxyl- L-cysteine

2014 ◽  
Vol 17 (1) ◽  
pp. 001-004 ◽  
Author(s):  
Benzhi Liu ◽  
Min Wang
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Sea Water ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Operational Parameters ◽  
Selective Determination ◽  
Self Assembled ◽  
Optimized Conditions

Application of gold nanoparticles self-assembled with N-carboxyl- L-cysteine for the determination of iron(III) was investigated. Differential pulse adsorptive stripping voltammetry was used to detect iron(III). Various operational parameters were investigated and discussed in terms of their effects on the measurement signals. A linear range from 0.1 nM to 1.8 nM with a detection limit of 0.03 nMwas obtained under optimized conditions. The applicability of the method was successfully tested by determination of iron(III) in sea water samples.

scholarly journals Adsorption of Guanine, Guanosine, and Adenine at Electrodes Studied by Differential Pulse Voltammetry and Electrochemical Impedance

Langmuir ◽  
2002 ◽  
Vol 18 (6) ◽  
pp. 2326-2330 ◽  
Author(s):  
Ana Maria Oliveira-Brett ◽  
Luís Antônio da Silva ◽  
Christopher M. A. Brett
Keyword(s):  
Differential Pulse Voltammetry ◽  
Electrochemical Impedance ◽  
Differential Pulse ◽  
Pulse Voltammetry

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.

scholarly journals Behavior of the guanosine monophosphate modified boron-doped diamond electrode in the presence of the pesticide alachlor

2015 ◽  
Vol 8 (2) ◽  
pp. 172-177 ◽  
Author(s):  
Jana Svítková ◽  
Ľubomír Švorc ◽  
Ján Labuda
Keyword(s):  
Electrochemical Impedance ◽  
Differential Pulse ◽  
Guanosine Monophosphate ◽  
Environmental Estrogen ◽  
Boron Doped Diamond ◽  
Diamond Electrode ◽  
Boron Doped ◽  
Boron Doped Diamond Electrode ◽  
Redox Indicator ◽  
Pulse Voltammetry

Abstract Alachlor (ALA) has been widely used in agriculture and may act as a carcinogen and an environmental estrogen. The present work deals with chemical modification of boron-doped diamond electrode (BDDE) by guanosine monophosphate (GMP) and its study in the presence of ALA. Cyclic voltammetry and electrochemical impedance spektroscopy in the presence of the redox indicator 1 × 10-3 mol/L [Fe(CN)6]3-/4- together with differential pulse voltammetry of the nucleotide base were explored to test effects of GMP immobilization time, the pesticide concentrations and incubation time in the pesticide solution. It was found that GMP layer on the BDDE surface is distorted after incubation in the ALA solution.

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