scholarly journals Electrodes Modification Based on Metal-Free Phthalocyanine: Example of Electrochemical Sensors for the Detection of Acetic Acid

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Amadou L. Ndiaye ◽  
Alain Pauly ◽  
Sebastien Delile ◽  
Jérôme Brunet ◽  
Christelle Varenne ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Electrochemical Sensors ◽  
Limit Of Detection ◽  
Modified Electrodes ◽  
Reduction Peak ◽  
Metal Free ◽  
Signal Decay ◽  
A Value ◽  
Working Electrode ◽  
Deposition Techniques

Electroanalytical properties of tetra-tert-butyl phthalocyanine (PcH2-tBu) modified electrodes are studied by cyclic voltammetry (CV). The modified electrodes are obtained by CV deposition techniques on gold (Au) and glassy carbon (C) screen-printed electrodes (SPEs) and used for the electrochemical detection of acetic acid (AA). Based on the CV experiments, the electrodeposition mechanism is detailed. The modified PcH2-tBu electrodes reveal one oxidation and one reduction peak within the potential window of the working electrodes. In the presence of the analyte (acetic acid), the modified electrodes show sensitivity in the range of 10 mM to 400 mM. For the PcH2-tBu modified Au electrode, a limit of detection (LOD) of 5.89 mM (based on the +0.06 V peak) was obtained while for the PcH2-tBu modified C electrode a LOD of 17.76 mM (based on the +0.07 V peak) was achieved. A signal decay of 17%, based on 20 experiments, is obtained when gold is used as working electrode. If carbon is used as working electrode a value of 7% is attained. A signal decay is observed after more than 50 cycles of experiments and is more pronounced when higher concentrations of acetic acid are used. A mechanism of sensing is proposed at the end.

scholarly journals DEVELOPMENT OF ELECTROCHEMICAL SENSORS FOR QUANTITATIVE ANALYSIS OF METHYLDOPA AT MODIFIED-GCE AND PGE ELECTRODES BY VOLTAMMETRY

2020 ◽  
Vol 4 (4) ◽  
pp. 223-236
Author(s):  
Suzan YANIK ◽  
Saliha B. KURT ◽  
Betul ARI ◽  
Sahin DEMIRCI ◽  
Selehattin YILMAZ
Keyword(s):  
Glassy Carbon ◽  
Sulfonic Acid ◽  
Electrochemical Sensors ◽  
Limit Of Detection ◽  
Modified Electrodes ◽  
Differential Pulse ◽  
Electrochemical Methods ◽  
Limit Of Quantification ◽  
Spectrophotometric Methods ◽  
Concentration Graphs

Methyldopa is one of the important drugs used in the treatment of high blood pressure (hypertension). In addition to various methods such as chromatographic and spectrophotometric methods, electrochemical methods are used for the determination of methyldopa. However, poly (p-aminobenzene sulfonic acid), pen-tip graphite electrode (PGE) study was not found in the literature search. Modified electrodes are important because they increase the sensitivity of the analysis. Furthermore, electrochemical methods have advantages such as being faster and cheaper than other instrumental analysis methods, being more sensitive, not requiring long pretreatments in the preparation of samples. In this study, the glassy carbon electrode (GCE) was modified with poly(p-aminobenzene sulfonic acid) to prepare poly (p-aminobenzene sulfonic acid) -modified glassy carbon electrodes. Cyclic voltammetry (CV) technique was used for the electropolymerization process. Methyldopa was selected in various concentrations of phosphate pH 7.40 buffer, anodic and cathodic voltamograms were taken and oxidation and reduction properties were investigated. Measurements were taken at different scanning rates by CV technique and the current type of methyldopa was determined. Peak flow-concentration graphs were drawn from the measurements taken by Differential Pulse Voltammetry (DPV) technique and the linearity range was 0.020- 2.500 µM for modified-GCE and 0.020-2.820 µM for PGE. The limit of detection (LOD) was calculated as 0.006 µM for modified-GCE, 0.012 µM for PGE. The limit of quantification (LOQ) was calculated as 0.020 µM for modified-GCE and 0.040 µM for PGE.

Electroanalysis of Catecholamine Drugs using Graphene Modified Electrodes

2019 ◽  
Vol 15 (4) ◽  
pp. 443-466 ◽  
Author(s):  
Mahya Karami Mosammam ◽  
Mohammad Reza Ganjali ◽  
Mona Habibi-Kool-Gheshlaghi ◽  
Farnoush Faridbod
Keyword(s):  
Electrochemical Sensors ◽  
Modified Electrodes ◽  
Electrochemical Methods ◽  
High Signal ◽  
Signal To Noise ◽  
Low Level ◽  
Biological Studies

Background: Catecholamine drugs are a family of electroactive pharmaceutics, which are widely analyzed through electrochemical methods. However, for low level online determination and monitoring of these compounds, which is very important for clinical and biological studies, modified electrodes having high signal to noise ratios are needed. Numerous materials including nanomaterials have been widely used as electrode modifies for these families during the years. Among them, graphene and its family, due to their remarkable properties in electrochemistry, were extensively used in modification of electrochemical sensors. Objective: In this review, working electrodes which have been modified with graphene and its derivatives and applied for electroanalyses of some important catecholamine drugs are considered.

scholarly journals Electrochemical Detection of Endosulfan Using an AONP-PANI-SWCNT Modified Glassy Carbon Electrode

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 723
Author(s):  
Kgotla K. Masibi ◽  
Omolola E. Fayemi ◽  
Abolanle S. Adekunle ◽  
Amal M. Al-Mohaimeed ◽  
Asmaa M. Fahim ◽  
...  
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Limit Of Detection ◽  
Modified Electrodes ◽  
Antimony Oxide ◽  
Current Response ◽  
Carbon Electrode ◽  
Trace Detection ◽  
Limit Of Quantification ◽  
Walled Carbon Nanotubes

This report narrates the successful application of a fabricated novel sensor for the trace detection of endosulfan (EDS). The sensor was made by modifying a glassy-carbon electrode (GCE) with polyaniline (PANI), chemically synthesized antimony oxide nanoparticles (AONPs), acid-functionalized, single-walled carbon nanotubes (fSWCNTs), and finally, the AONP-PANI-SWCNT nanocomposite. The electrochemical properties of the modified electrodes regarding endosulfan detection were investigated via cyclic voltammetry (CV) and square-wave voltammetry. The current response of the electrodes to EDS followed the trend GCE-AONP-PANI-SWCNT (−510 µA) > GCE-PANI (−59 µA) > GCE-AONPs (−11.4 µA) > GCE (−5.52 µA) > GCE-fSWCNTs (−0.168 µA). The obtained results indicated that the current response obtained at the AONP-PANI-SWCNT/GCE was higher with relatively low overpotential compared to those from the other electrodes investigated. This demonstrated the superiority of the AONP-PANI-SWCNT-modified GCE. The AONP-PANI-SWCNT/GCE demonstrated good electrocatalytic activities for the electrochemical reduction of EDS. The results obtained in this study are comparable with those in other reports. The sensitivity, limit of detection (LoD), and limit of quantification (LoQ) of AONP-PANI-SWCNT/GCE towards EDS was estimated to be 0.0623 µA/µM, 6.8 µM, and 20.6 µM, respectively. Selectivity, as well as the practical application of the fabricated sensor, were explored, and the results indicated that the EDS-reduction current was reduced by only 2.0% when interfering species were present, whilst average recoveries of EDS in real samples were above 97%.

scholarly journals Quantification of DNA by a Thermal-Durable Biosensor Modified with Conductive Poly(3,4-ethylenedioxythiophene)

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3684 ◽  
Author(s):  
Yesong Gu ◽  
Po-Yuan Tseng ◽  
Xiang Bi ◽  
Jason Yang
Keyword(s):  
Gold Nanoparticles ◽  
Limit Of Detection ◽  
Differential Pulse ◽  
Complementary Sequence ◽  
Signal Decay ◽  
Target Dna ◽  
Hybridization Efficiency ◽  
Sh Group ◽  
Polymerase Chain ◽  
Or Gene

The general clinical procedure for viral DNA detection or gene mutation diagnosis following polymerase chain reaction (PCR) often involves gel electrophoresis and DNA sequencing, which is usually time-consuming. In this study, we have proposed a facile strategy to construct a DNA biosensor, in which the platinum electrode was modified with a dual-film of electrochemically synthesized poly(3,4-ethylenedioxythiophene) (PEDOT) resulting in immobilized gold nanoparticles, with the gold nanoparticles easily immobilized in a uniform distribution. The DNA probe labeled with a SH group was then assembled to the fabricated electrode and employed to capture the target DNA based on the complementary sequence. The hybridization efficiency was evaluated with differential pulse voltammetry (DPV) in the presence of daunorubicin hydrochloride. Our results demonstrated that the peak current in DPV exhibited a linear correlation the concentration of target DNA that was complementary to the probe DNA. Moreover, the electrode could be reused by heating denaturation and re-hybridization, which only brought slight signal decay. In addition, the addition of the oxidized form of nicotinamide adenine dinucleotide (NAD+) could dramatically enhance the sensitivity by more than 5.45-fold, and the limit-of-detection reached about 100 pM.

scholarly journals Application of Carbon Nanomaterials Decorated Electrochemical Sensor for Analysis of Environmental Pollutants

2021 ◽  
Author(s):  
Sunil Kumar ◽  
Abhay Nanda Srivastva
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanomaterials ◽  
Electrochemical Sensors ◽  
Anodic Stripping Voltammetry ◽  
Environmental Pollutants ◽  
Stripping Voltammetry ◽  
Metal Electrode ◽  
Effective Area ◽  
Electrochemical Sensing ◽  
Working Electrode

Carbon nanomaterials (CNMs), especially carbon nanotubes and graphene, have been attracting tremendous attention in environmental analysis for rapid and cost effective detection of various analytes by electrochemical sensing. CNMs can increase the electrode effective area, enhance the electron transfer rate between the electrode and analytes, and/or act as catalysts to increase the efficiency of electrochemical reaction, detection, adsorption and removal are of great significance. Various carbon nanomaterials including carbon nanotubes, graphene, mesoporous carbon, carbon dots exhibited high adsorption and detection capacity. Carbon and its derivatives possess excellent electro catalytic properties for the modified sensors, electrochemical methods usually based on anodic stripping voltammetry at some modified carbon electrodes. Metal electrode detection sensitivity is enhanced through surface modification of working electrode (GCE). Heavy metals have the defined redox potential. A remarkable deal of efficiency with the electrochemical sensors can be succeeded by layering the surface of the working electrode with film of active electro-catalytic species. Usually, electro catalysts used for fabrication of sensors are surfactants, nano-materials, polymers, carbon-based materials, organic ligands and biomaterials.

scholarly journals Comparative Assessment of the Analytical Parameters in Ascorbic Acid and Sulphite Assay at a Spectrographic Carbon Working Electrode

2018 ◽  
Vol 1 (1) ◽  
pp. 465-469
Author(s):  
Aurelia Magdalena Pisoschi ◽  
Aneta Pop
Keyword(s):  
Ascorbic Acid ◽  
Linear Response ◽  
Analytical Signal ◽  
Comparative Investigation ◽  
Comparative Assessment ◽  
Reduction Peak ◽  
Working Electrode ◽  
Relative Standard ◽  
Electro Oxidation ◽  
Analytical Range

Abstract The aim of this study is the comparative investigation of spectrographic carbon electrode’s viability as working electrode, in ascorbic acid and sulphite asssessment. Cyclic voltammetry involves a linear sweeping of the potential, the analytical signal being represented by the anodic oxidation /cathodic reduction peak of the analyte. For both analytes, the electro-oxidation resulted in an anodic peak, correlable with ascorbic acid / sulphite concentration. The analytical range of linear response corresponded to 0.07 - 10 mM for ascorbic acid and to 15.5 mg/L - 4 g/L for sulphite. The relative standard deviation RSD (%) was 2.71 % for ascorbic acid and 2.88 % for sulphite. The sensitivities, given by the slopes of the calibration graphs were 88.88 μA/mmole/L for ascorbic acid and 477.37 μA/g/L for sulphite.

scholarly journals Application of biosynthesized metal nanoparticles in electrochemical sensors

2021 ◽  
pp. 77-77
Author(s):  
Totka Dodevska ◽  
Dobrin Hadzhiev ◽  
Ivan Shterev ◽  
Yanna Lazarova
Keyword(s):  
Green Synthesis ◽  
Metal Nanoparticles ◽  
Electrochemical Sensors ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Cost Effective ◽  
Electrochemical Sensing ◽  
Synthesis Methods ◽  
Range Limit ◽  
Wide Range

Recently, the development of eco-friendly, cost-effective and reliable methods for synthesis of metal nanoparticles has drawn a considerable attention. The so-called green synthesis, using mild reaction conditions and natural resources as plant extracts and microorganisms, has established as a convenient, sustainable, cheap and environmentally safe approach for synthesis of a wide range of nanomaterials. Over the past decade, biosynthesis is regarded as an important tool for reducing the harmful effects of traditional nanoparticle synthesis methods commonly used in laboratories and industry. This review emphasizes the significance of biosynthesized metal nanoparticles in the field of electrochemical sensing. There is increasing evidence that green synthesis of nanoparticles provides a new direction in designing of cost-effective, highly sensitive and selective electrode-catalysts applicable in food, clinical and environmental analysis. The article is based on 157 references and provided a detailed overview on the main approaches for green synthesis of metal nanoparticles and their applications in designing of electrochemical sensor devices. Important operational characteristics including sensitivity, dynamic range, limit of detection, as well as data on stability and reproducibility of sensors have also been covered. Keywords: biosynthesis; green synthesis; nanomaterials; nanotechnology; modified electrodes

scholarly journals Laccase Electrochemical Biosensor Based on Graphene-Gold/Chitosan Nanocomposite Film for Bisphenol A Detection

2020 ◽  
Vol 16 (5) ◽  
pp. 570-579
Author(s):  
Fuzi M. Fartas ◽  
Jaafar Abdullah ◽  
Nor A. Yusof ◽  
Yusran Sulaiman ◽  
Mohd I. Saiman ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Electrochemical Biosensor ◽  
Limit Of Detection ◽  
Modified Electrodes ◽  
Electrochemical Performances ◽  
Carbon Electrode ◽  
Screen Printed Carbon Electrode ◽  
Laccase Enzyme ◽  
Bisphenol A Detection ◽  
Screen Printed

Background: Bisphenol A (BPA) is considered one of the most common chemicals that could cause environmental endocrine disrupting. Therefore, there is an increasing demand for simple, rapid and sensitive methods for BPA detection that result from BPA leaching into foods and beverages from storage containers. Herein, a simple laccase electrochemical biosensor was developed for the determination of BPA based on Screen-Printed Carbon Electrode (SPCE) modified graphenegold/ chitosan. The synergic effect of graphene-gold/chitosan nanocomposite as electrode modifier greatly facilitates electron-transfer processes between the electrolyte and laccase enzyme, thus leads to a remarkably improved sensitivity for bisphenol A detection. Methods: In this study, laccase enzyme is immobilized onto the Screen-Printed Carbon Electrode (SPCE) modified Graphene-Decorated Gold Nanoparticles (Gr-AuNPs) with Chitosan (Chit). The surface structure of nanocomposite was studied using different techniques including Field Emission Scanning Microscopy (FESEM), TRANSMISSION Electron Microscopy (TEM), Raman spectroscopy and Energy Dispersive X-ray (EDX). Meanwhile, the electrochemical performances of the modified electrodes were studied using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV). Results: The developed laccase biosensor offered excellent analytical performance for the detection of BPA with a sensitivity of 0.271 μA/μM and Limit of Detection (LOD) of 0.023 μM, respectively. Moreover, the constructed biosensor showed good reproducibility, selectivity and stability towards BPA. The sensor has been used to detect BPA in a different type of commercial plastic products as a real sample and satisfactory result was obtained when compared with the HPLC method. Conclusion: The proposed electrochemical laccase biosensor exhibits good result which is considered as a promising candidate for a simple, rapid and sensitive method especially in the resource- limited condition.

scholarly journals Microfabricated Au-Film Sensors for the Voltammetric Determination of Hg(II)

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1518
Author(s):  
Maria Tsetsoni ◽  
Eleni Roditi ◽  
Christos Kokkinos ◽  
Anastasios Economou
Keyword(s):  
Electrode Surface ◽  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Voltammetric Determination ◽  
Film Sensor ◽  
Au Film ◽  
Working Electrode ◽  
Anodic Stripping

In this work, a microfabricated Au-film sensor was designed and fabricated for thevoltammmetric determination of Hg(II). The electrode was fabricated on a silicon chip with astandard microengineering approach utilizing photolithography for patterning the electrode shapeand sputtering for deposition of thin Cr and Au films on the surface of the sensors. The sensorswere used for the determination of trace Hg(II) with anodic stripping voltammetry (ASV): initiallyHg(II) in the sample was accumulated on the Au working electrode surface by reduction andformation of an Au(Hg) amalgam followed by oxidation of the preconcentrated metallic Hg using asquare wave voltammetric scan. The limit of detection was 1.5μgL−1 and the coefficient of variationof 10 consecutive measurements was 3.1%.

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