scholarly journals Nanoelectrode Ensembles Consisting of Carbon Nanotubes

2021 ◽  
Vol 11 (18) ◽  
pp. 8399
Author(s):  
Gabrielle R. Dangel ◽  
Hope Kumakli ◽  
Connor E. Rahm ◽  
Ryan White ◽  
Noe T. Alvarez
Keyword(s):  
Carbon Nanotubes ◽  
Cross Sections ◽  
Electrode Materials ◽  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Electrochemical Testing ◽  
Aspect Ratios ◽  
Scientific Innovation ◽  
Random Arrays

Incorporating the nanoscale properties of carbon nanotubes (CNTs) and their assemblies into macroscopic materials is at the forefront of scientific innovation. The electrical conductivity, chemical inertness, and large aspect ratios of these cylindrical structures make them ideal electrode materials for electrochemical studies. The ability to assemble CNTs into nano-, micro-, and macroscale materials broadens their field of applications. Here, we report the fabrication of random arrays of CNT cross-sections and their performance as nanoelectrode ensembles (NEEs). Single ribbons of drawable CNTs were employed to create the CNT-NEEs that allows easier fabrication of nanoscale electrodes for general electrochemical applications. Surface analysis of the prepared NEEs using scanning electron microscopy showed a random distribution of CNTs within the encapsulating polymer. Electrochemical testing via cyclic voltammetry and scanning electrochemical cell microscopy revealed voltametric differences from the typical macroelectrode response with the steady-state nature of NEEs. Finally, when the NEE was employed for Pb2+ detection using square-wave anodic stripping voltammetry, a limit of detection of 0.57 ppb with a linear range of 10–35 ppb was achieved.

scholarly journals Anodic Stripping Voltammetry with the Hanging Mercury Drop Electrode for Trace Metal Detection in Soil Samples

Chemosensors ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 107
Author(s):  
Kequan Xu ◽  
Clara Pérez-Ràfols ◽  
Amine Marchoud ◽  
María Cuartero ◽  
Gastón A. Crespo
Keyword(s):  
Metal Ions ◽  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Hanging Mercury Drop Electrode ◽  
Mercury Drop Electrode ◽  
Redox Active ◽  
Active Metal ◽  
Metal Detection ◽  
Trace Metal Detection

The widely spread use of the hanging mercury drop electrode (HMDE) for multi-ion analysis is primarily ascribed to the following reasons: (i) excellent reproducibility owing to the easy renewal of the electrode surface avoiding any hysteresis effect (i.e., a new identical drop is generated for each measurement to be accomplished); (ii) a wide cathodic potential window originating from the passive hydrogen evolution and solvent electrolysis; (iii) the ability to form amalgams with many redox-active metal ions; and (iv) the achievement of (sub)nanomolar limits of detection. On the other hand, the main controversy of the HMDE usage is the high toxicity level of mercury, which has motivated the scientific community to question whether the HMDE deserves to continue being used despite its unique capability for multi-metal detection. In this work, the simultaneous determination of Zn2+, Cd2+, Pb2+, and Cu2+ using the HMDE is investigated as a model system to evaluate the main features of the technique. The analytical benefits of the HMDE in terms of linear range of response, reproducibility, limit of detection, proximity to ideal redox behavior of metal ions and analysis time are herein demonstrated and compared to other electrodes proposed in the literature as less-toxic alternatives to the HMDE. The results have revealed that the HMDE is largely superior to other reported methods in several aspects and, moreover, it displays excellent accuracy when simultaneously analyzing Zn2+, Cd2+, Pb2+, and Cu2+ in such a complex matrix as digested soils. Yet, more efforts are required towards the definitive replacement of the HMDE in the electroanalysis field, despite the elegant approaches already reported in the literature.

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 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%.

scholarly journals Nanostructured materials for sensing Pb(II) and Cd(II) ions: Manganese oxohydroxide versus carbonized polyanilines?

2013 ◽  
Vol 78 (11) ◽  
pp. 1717-1727 ◽  
Author(s):  
Biljana Sljukic ◽  
Darko Micic ◽  
Nikola Cvjeticanin ◽  
Gordana Ciric-Marjanovic
Keyword(s):  
Nanostructured Materials ◽  
Electrode Materials ◽  
Anodic Stripping Voltammetry ◽  
Aqueous Media ◽  
Stripping Voltammetry ◽  
Lead And Cadmium ◽  
Manganese Oxyhydroxide ◽  
The One ◽  
Lower Limits

Nanostructured materials including three different carbonized polyanilines and manganese oxyhydroxide were prepared and evaluated as electrode materials for sensing of lead and cadmium ions in aqueous media. Anodic stripping voltammetry results indicated that all prepared materials could be successfully used for determination of these two heavy metal ions. Carbonized polyaniline-based electrodes have higher signal and lower limits of detection (10-7 ?) compared to manganese oxyhydroxide-based electrode. Among the three studied carbonized polyanilines, the one that was derived from polyaniline precursor produced in the presence of 3,5-dinitrosalicyclic acid showed the highest electrocatalytic activity towards the lead and cadmium oxidation.

scholarly journals Glass-like carbon, pyrolytic graphite or nanostructured carbon for electrochemical sensing of bismuth ion?

2016 ◽  
Vol 10 (2) ◽  
pp. 87-95 ◽  
Author(s):  
Jadranka Milikic ◽  
Nevena Markicevic ◽  
Aleksandar Jovic ◽  
Radmila Hercigonja ◽  
Biljana Sljukic
Keyword(s):  
Deposition Time ◽  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Pyrolytic Graphite ◽  
Stripping Voltammetry ◽  
Electrochemical Sensing ◽  
Nanostructured Carbon ◽  
Ion Sensing ◽  
Current Densities ◽  
Pyrolytic Graphite Electrode

Different carbon electrodes were explored for application in electroanalysis, namely for sensing of bismuth ion as model analyte. Carbon materials tested included glassy carbon, basal and edge plane pyrolytic graphite, as well as nanostructured carbonized polyaniline prepared in the presence of 3,5-dinitrosalicylic acid. Bismuth ion was chosen as model analyte as protocol for its detection and quantifications is still to be determined. Herein, anodic stripping voltammetry was used with study of effect of several parameters such as scan rate and deposition time. Electrode based on carbonized polyaniline showed the highest activity for bismuth ion sensing in terms of the highest current densities recorded both in a laboratory and in real sample, while basal plane pyrolytic graphite electrode gave the lowest limit of detection.

scholarly journals Chemical Detection by Analyte-Induced Change in Electrophoretic Deposition of Gold Nanoparticles

2021 ◽  
Author(s):  
Badri Mainali ◽  
Francis Patrick Zamborini
Keyword(s):  
Electrophoretic Deposition ◽  
Indium Tin Oxide ◽  
Negative Charge ◽  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Au Nps ◽  
Hydronium Ions ◽  
Glass Electrodes

Abstract The electrophoretic deposition (EPD) of citrate-stabilized Au nanoparticles (cit-Au NPs) occurs on indium tin oxide (ITO)-coated glass electrodes upon electrochemical oxidation of hydroquinone (HQ) due to the release of hydronium ions. Anodic stripping voltammetry (ASV) for Au oxidation allows the determination of the amount of Au NP deposition under a specific EPD potential and time. The binding of Cr3+ to the cit-Au NPs inhibits the EPD by inducing aggregation and/or reducing the negative charge, which could lower the effective NP concentration of the cit-Au NPs and/or lower the electrophoretic mobility. This lowers the Au oxidation charge in the ASV, which acts as an indirect signal for Cr3+. The binding of melamine to cit-Au NPs similarly leads to aggregation and/or lowers the negative charge, also resulting in reduction of the ASV Au oxidation peak. The decrease in Au oxidation charge measured by ASV increases linearly with increasing Cr3+ and melamine concentration. The limit of detection (LOD) for Cr3+ is 21.1 ppb and 16.0 ppb for 15.1 and 4.1 nm diameter cit-Au NPs, respectively. Improving the sensing conditions allows for as low as 1 ppb detection of Cr3+. The LOD for melamine is 45.7 ppb for 4.1 nm Au NPs.

scholarly journals Trace Analysis of Heavy Metals (Cd, Pb, Hg) Using 3D Printed graphene/PLA Composite Electrodes

2019 ◽  
Author(s):  
John Walters ◽  
Shakir Ahmed ◽  
Irina Terrero Rodriguez ◽  
Glen O'Neil
Keyword(s):  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Composite Electrodes ◽  
Carbon Structure ◽  
Anodic Stripping ◽  
3D Printed ◽  
Pipette Tip ◽  
20 Nm ◽  
Scanning Electron

Here we investigate the use of 3D printed graphene/PLA electrodes for quantifying trace amounts of Hg, Pb, and Cd. We prepared cylindrical electrodes by sealing a 600 µm diameter graphene/PLA filament in a pipette tip filled with epoxy. We characterized the electrodes using scanning electron microscopy, Raman spectroscopy, and cyclic voltammetry in ferrocene methanol. The physical characterization showed a significant amount of disorder in the carbon structure and the electrochemical characterization showed quasi-reversible behavior without any electrode pretreatment. We then used unmodified graphene/PLA electrode to quantify Hg, and Pb and Cd in 0.01 M HCl and 0.1 M acetate buffer using square wave anodic stripping voltammetry. We were able to quantify Hg with a limit of detection (LOD) of 6.1 nM (1.2 ppb), but Pb and Cd did not present measurable peaks at concentrations below ~400 nM. We improved the LODs for Pb and Cd by depositing Bi microparticles on the graphene/PLA and, after optimization, achieved clear stripping peaks at the 20 nM level for both ions (4.1 and 2.2 ppb for Pb2+ and Cd2+, respectively). The results obtained for all three metals allowed quantification below the EPA action limits in drinking water.

scholarly journals Analisis Logam Fe dengan Teknik Voltammetri Pelucutan Anodik Pulsa Diferensial dalam Tanaman Pakcoy dari Perkebunan Sayur Bedugul Bali

2018 ◽  
Vol 4 (2) ◽  
pp. 168-173
Author(s):  
Irdhawati Irdhawati ◽  
Rosanti Suryani Tince Mbatu ◽  
Emmy Sahara
Keyword(s):  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Deposition Potential ◽  
Counter Electrodes ◽  
Percent Recovery ◽  
Measurement Results ◽  
Standard Solution ◽  
Synthetic Fertilizers

Pakcoy is one of the most popular vegetable. The use of synthetic fertilizers and pesticides contain heavy metals can contaminate pakcoy vegetable. This research aims to determine the validity of measurements and concentration of Fe in pakcoy using differential pulse anodic stripping voltammetry technique.The working, reference, and counter electrodes were platinum disk, Ag/AgCl, and Pt wire, respectively. The optimum measurement results of the standard solutions of Fe(III) obtained the optimum deposition time was 70 seconds, the optimum scan rate was 10 mV/s, and the optimum deposition potential at -0.47 V. A linear concentration of standard solution of Fe(III) observed at the range of 50 ppb~500 ppb, with correlation coefficient 0.9954. Limit of detection was 50.18 ppb. The repetition of 10 times measurements had a Horwitz ratio of less than 2. Percent recovery was 100.26% ± 0.27%. The average of Fe(III) concentration in the samples from 5 (five) locations of the pakcoy sampling contains 3.82±0.29 ppm, less than SNI treshold line of 5.0 ppm.  

scholarly journals Trace Analysis of Heavy Metals (Cd, Pb, Hg) Using 3D Printed graphene/PLA Composite Electrodes

2019 ◽  
Author(s):  
John Walters ◽  
Shakir Ahmed ◽  
Irina Terrero Rodriguez ◽  
Glen O'Neil
Keyword(s):  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Composite Electrodes ◽  
Carbon Structure ◽  
Anodic Stripping ◽  
3D Printed ◽  
Pipette Tip ◽  
20 Nm ◽  
Scanning Electron

Here we investigate the use of 3D printed graphene/PLA electrodes for quantifying trace amounts of Hg, Pb, and Cd. We prepared cylindrical electrodes by sealing a 600 µm diameter graphene/PLA filament in a pipette tip filled with epoxy. We characterized the electrodes using scanning electron microscopy, Raman spectroscopy, and cyclic voltammetry in ferrocene methanol. The physical characterization showed a significant amount of disorder in the carbon structure and the electrochemical characterization showed quasi-reversible behavior without any electrode pretreatment. We then used unmodified graphene/PLA electrode to quantify Hg, and Pb and Cd in 0.01 M HCl and 0.1 M acetate buffer using square wave anodic stripping voltammetry. We were able to quantify Hg with a limit of detection (LOD) of 6.1 nM (1.2 ppb), but Pb and Cd did not present measurable peaks at concentrations below ~400 nM. We improved the LODs for Pb and Cd by depositing Bi microparticles on the graphene/PLA and, after optimization, achieved clear stripping peaks at the 20 nM level for both ions (4.1 and 2.2 ppb for Pb2+ and Cd2+, respectively). The results obtained for all three metals allowed quantification below the EPA action limits in drinking water.

Sign in / Sign up

Export Citation Format

Share Document