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%.

Electrochemical Study of Pyrene on Glassy Carbon Electrode Modified with Metal-Oxide Nanoparticles and Graphene Oxide/Multi-Walled Carbon Nanotubes Nanoplatform

2016 ◽  
Vol 44 ◽  
pp. 158-195
Author(s):  
Diseko Boikanyo ◽  
Abolanle S. Adekunle ◽  
Eno E. Ebenso
Keyword(s):  
Carbon Nanotubes ◽  
Electron Transfer ◽  
Graphene Oxide ◽  
Glassy Carbon Electrode ◽  
Rate Constant ◽  
Glassy Carbon ◽  
Limit Of Detection ◽  
Carbon Electrode ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This work describes and compares the electron transport and electrocatalytic properties of chemically synthesised cobalt oxide (Co3O4) and nickel oxide (NiO) nanoparticles grafted onto graphene oxide (GO)/acid treated multi-walled carbon nanotubes decorated glassy carbon electrode. Successful synthesis of these nano materials was confirmed using microscopic and spectroscopic techniques. Successful modification of electrode was confirmed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Results showed that the GCE-fMWCNT-NiO and GCE-fMWCNT- Co3O4 nanocomposite modified electrodes gave faster electron transfer process in both 5 mM Ferri/Ferro ([Fe(CN)6]3−/4−) redox probe and 0.1 M phosphate buffer solution (PBS). GCE-fMWCNT-NiO and GCE-fMWCNT-Co3O4 electrodes also gave enhanced Pyrene oxidation current compared with bare GCE and other electrodes studied. The charge transfer resistance, electron transfer rate constant (ks), Tafel value, limit of detection (LoD), sensitivity, adsorption equilibrium constant (β), Gibbs free energy change due to the adsorption (ΔGoads) of Pyrene onto the GCE-fMWCNT-Co3O4 are established and discussed. The LoD and ΔGoads for Pyrene were 1.62 nM and -15.8 kJ/mol, respectively, over a linear dynamic range of 1.0 x 10-9 – 100 x 10-9 M. The electro-oxidation of Pyrene was a diffusion dominated process, but demonstrated adsorption thought to be as a result of a combination of the strong pi-pi electron interactions between Pyrene and the MWCNT, thus the thin film formed on the surface of the electrode by the analyte and its reaction intermediates. The LoD compared favourably with literature reported values. GCE-fMWCNT-Co3O4 gave better performance to Pyrene electrooxidation, good resistance to electrode fouling, higher catalytic rate constant and lower limit of detection. The sensor is easy to fabricate, cost effective and could be used for routine determination of Pyrene in food and environmental matrices.

scholarly journals Method validation in quantitative electrochemical analysis of colchicine using glassy carbon electrode

2007 ◽  
Vol 5 (3) ◽  
pp. 766-778 ◽  
Author(s):  
Ede Bodoki ◽  
Robert Săndulescu ◽  
Liviu Roman
Keyword(s):  
Detection Limit ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Limit Of Detection ◽  
Electrochemical Analysis ◽  
Carbon Electrode ◽  
Cathodic Peak ◽  
Limit Of Quantification ◽  
Validation Parameters

AbstractA cathodic differential pulse voltammetric determination of colchicine was validated using a glassy carbon electrode in HClO4/H3PO4 0.01 M. Colchicine gives an irreversible, diffusion-controlled peak at −862 mV vs. Ag/AgCl reference electrode. The cathodic peak is strongly influenced by a more alkaline environment with a shift towards more negative potentials. Method optimization was carried out in parallel for three types of electrodes (glassy carbon, mercury film and bismuth film coated glassy carbon). The cathodic peak current is higher using film-coated electrodes, but shows poorer intra-day reproducibility and a longer analysis time due to film renewal. Thus, a bare glassy carbon electrode was used to determine colchicine in the concentration range of 2.4 − 50 μg mL−1 (R 2 = 0.9998, n = 5), with a calculated detection limit of 0.80 μg mL−1. The proposed method was characterized according to ICH Harmonized Tripartite Guidance Q2(R1) by validation parameters (selectivity, linearity, accuracy, fidelity, limit of detection, limit of quantification) and it was successfully applied for the determination of colchicine from tablets, without the interference of the excipients. The method’s performances were evaluated and compared with both a known polarographic method and the official quantitative spectrophotometric determination from the Romanian Pharmacopoeia, Xth edition, respectively.

scholarly journals Electrochemical detection of cholesterol in a buffer solution with a glassy carbon electrode doctored by ZnO/SnO2/RuO2 nanomaterials

2021 ◽  
Author(s):  
Md Mahmud Alam ◽  
M.T. Uddin ◽  
Abdullah M. Asiri ◽  
Mohammed M. Rahman ◽  
M.A. Islam
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Calibration Curve ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Elapse Time ◽  
Current Response ◽  
Carbon Electrode ◽  
Buffer Solution ◽  
Reliable Technique

Abstract This electrochemical study performed to develop a cholesterol sensor using a glassy carbon electrode (GCE) coating with ternary low-dimensional ZnO/SnO2/RuO2 nanomaterials (NMs). The ZnO/SnO2/RuO2 NMs characterized using FESEM, XPS, EDS and XRD analysis. The desired cholesterol sensor fabricated by coating a GCE with ZnO/SnO2/RuO2 NMs as a film of the thin-layer using suspension of ethanol with 5% Nafion binder, which performed to the analysis of cholesterol electrochemically in the phosphate buffer phase. The resulted electrochemical responses have exhibited the linearity from 0.1nM ~ 0.01mM of cholesterol in current versus concentration plot, which defined as a calibration curve of this sensor development. The linear concentration (0.1nM ~ 0.01mM) of cholesterol corresponding with the current response is known as the dynamic range (LDR) for detection of target analyte. The sensitivity is calculated from the slope of calibration-curve found as 11.3513 µAµM− 1cm− 2. The lower limit of detection (91.42 ± 4.57 pM) is obtained from signal/noise (S/N = 3) at 3. In the real-samples detection process, the fabricated cholesterol sensor is exhibited good reproducibility, fast response time and ability to perform in long-duration of sensor elapse time. In the end, this method is shown the reliable detection of cholesterol in the buffer phase and would be very perspective in the recent future in-term of a simple as well as reliable technique in the field of pathological diagnosis.

scholarly journals Facile Electrochemical Determination of Methotrexate (MTX) Using Glassy Carbon Electrode-Modified with Electronically Disordered NiO Nanostructures

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1266
Author(s):  
Aftab A. Khand ◽  
Saeed A. Lakho ◽  
Aneela Tahira ◽  
Mohd Ubaidullah ◽  
Asma A. Alothman ◽  
...  
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Limit Of Detection ◽  
Linear Sweep Voltammetry ◽  
Pharmaceutical Products ◽  
Linear Range ◽  
Carbon Electrode ◽  
Limit Of Quantification ◽  
Recovery Method

Recently, the oxidative behavior of methotrexate (MTX) anticancer drug is highly demanded, due to its side effects on healthy cells, despite being a very challenging task. In this study, we have prepared porous NiO material using sodium sulfate as an electronic disorder reagent by hydrothermal method and found it highly sensitive and selective for the oxidation of MTX. The synthesized NiO nanostructures were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques. These physical characterizations delineated the porous morphology and cubic crystalline phase of NiO. Different electrochemical approaches have been utilized to determine the MTX concentrations in 0.04 M Britton–Robinson buffer (BRB) at pH 2 using glassy carbon electrode (GCE)-modified with electronically disordered NiO nanostructures. The linear range for MTX using cyclic voltammetry (CV) was found to be from 5 to 30 nM, and the limit of detection (LOD) and limit of quantification (LOQ) were 1.46 nM and 4.86 nM, respectively, whereas the linear range obtained via linear sweep voltammetry (LSV) was estimated as 15–90 nM with LOD and LOQ of 0.819 nM and 2.713 nM, respectively. Additionally, amperometric studies revealed a linear range from 10 to70 nM with LOD and LOQ of 0.1 nM and 1.3 nM, respectively. Importantly, MTX was successfully monitored in pharmaceutical products using the standard recovery method. Thus, the proposed approach for the synthesis of active metal oxide materials could be sued for the determination of other anticancer drugs in real samples and other biomedical applications.

scholarly journals Simultaneous electrochemical sensing of dihydroxy benzene isomers at cost-effective allura red polymeric film modified glassy carbon electrode

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pattan-Siddappa Ganesh ◽  
Ganesh Shimoga ◽  
Seok-Han Lee ◽  
Sang-Youn Kim ◽  
Eno E. Ebenso
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Limit Of Detection ◽  
Tap Water ◽  
Differential Pulse ◽  
Oxidation Potential ◽  
Electrochemical Sensing ◽  
Carbon Electrode ◽  
Buffer Solution ◽  
Allura Red

Abstract Background A simple and simultaneous electrochemical sensing platform was fabricated by electropolymerization of allura red on glassy carbon electrode (GCE) for the interference-free detection of dihydroxy benzene isomers. Methods The modified working electrode was characterized by electrochemical and field emission scanning electron microscopy methods. The modified electrode showed excellent electrocatalytic activity for the electrooxidation of catechol (CC) and hydroquinone (HQ) at physiological pH of 7.4 by cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques. Results The effective split in the overlapped oxidation signal of CC and HQ was achieved in a binary mixture with peak to peak separation of 0.102 V and 0.103 V by CV and DPV techniques. The electrode kinetics was found to be adsorption-controlled. The oxidation potential directly depends on the pH of the buffer solution, and it witnessed the transfer of equal number of protons and electrons in the redox phenomenon. Conclusions The limit of detection (LOD) for CC and HQ was calculated to be 0.126 μM and 0.132 μM in the linear range of 0 to 80.0 μM and 0 to 110.0 μM, respectively, by ultra-sensitive DPV technique. The practical applicability of the proposed sensor was evaluated for tap water sample analysis, and good recovery rates were observed. Graphical abstract Electrocatalytic interaction of ALR/GCE with dihydroxy benzene isomers.

scholarly journals Electrochemical Determination of Capsaicinoids Content in Soy Sauce and Pot-Roast Meat Products Based on Glassy Carbon Electrode Modified with Β-Cyclodextrin/Carboxylated Multi-Wall Carbon Nanotubes

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1743
Author(s):  
Qianhui Gu ◽  
Chaoqun Lu ◽  
Kangwen Chen ◽  
Xingguang Chen ◽  
Pengfei Ma ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Sensor ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Meat Products ◽  
Soy Sauce ◽  
Relative Dispersion ◽  
Carbon Electrode ◽  
Trace Detection ◽  
Multi Wall Carbon Nanotubes

The rapid quantification of capsaicinoids content is very important for the standardization of pungent taste degree and flavor control of soy sauce and pot-roast meat products. To rapidly quantify the capsaicinoids content in soy sauce and pot-roast meat products, an electrochemical sensor based on β-cyclodextrin/carboxylated multi-wall carbon nanotubes was constructed and the adsorptive stripping voltammetry method was used to enrich samples in this study. The results showed that the excellent performance of the established electrochemical sensor was mostly because β-cyclodextrin caused the relative dispersion of carboxylated multi-wall carbon nanotubes on the glassy carbon electrode surface. Capsaicin and dihydrocapsaicin had similar electrochemical behavior, so the proposed method could determine the total content of capsaicinoids. The linearity of capsaicinoids content was from 0.5 to 100 μmol/L and the detection limit was 0.27 μmol/L. The recovery rates of different capsaicinoids content were between 83.20% and 136.26%, indicating the proposed sensor could realize trace detection of capsaicinoids content in sauce and pot-roast meat products. This work provides a research basis for pungent taste degree standardization and flavor control in the food industry.

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