Understanding Voltammetry

Compton, Richard G.; Kätelhön, Enno; Ward, Kristopher R.; Laborda, Eduardo

doi:10.1142/q0246

Cited by 141 publications

(242 citation statements)

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“…The electroactive area of the prepared electrode was estimated by cyclic voltammetry (CV) using 5.0×10 −3 M K 3 Fe(CN) 6 in 0.1 M KCl by recording the current‐voltage curve at different scan rates. The Randles‐Ševčík equation for a quasi‐reversible process was used :

true I_{P} = 2.65 \times 10^{5} n^{\frac{3}{2}} A D^{\frac{1}{2}} C v^{\frac{1}{2}}

…”

Section: Resultsmentioning

confidence: 99%

Graphite/Nanocrystalline Zeolite Platform for Selective Electrochemical Determination of Hepatitis C Inhibitor Ledipasvir

et al. 2018

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A simple and efficient procedure is described for the electrochemical determination of ledipasvir (LDP) in presence of co‐formulated drug sofosbuvir (SOF). Herein, a highly sensitive, low‐cost electrochemical protocol was utilized to fabricate a zeolite modified carbon paste electrode (ZY/CPE) through mixing of zeolite nanostructures with graphite powder. The fabricated sensor displayed high sensitivity, allowing optimal charge transfer/electrode kinetics. Different experimental and chemical factors, including electrode composition, effect of pH, scan rate and amount of ZY were evaluated carefully to obtain the highest electrochemical response. Under optimized conditions and using square wave voltammetry (SWV), the current response of the ZY/CPE electrochemical sensing platform exhibited a detection limit of 7.5×10−9 M and a large linear range from 5.0×10−8 to 1.0×10−4 M. The practical applicability of the suggested electrochemical platform was verified in the assessment of LDP in pharmaceutical formulations with excellent recoveries in the range of 99.50–98.87 %. Moreover, a biological relevance of the developed sensor was established by the analysis of LDP in human urine and plasma samples with satisfactory recoveries of 99.00 and 99.68 %, respectively. Due to the simplicity and ease of preparation of the proposed sensor, it can be used in quality control laboratories and for clinical analysis.

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true I_{P} = 2.65 \times 10^{5} n^{\frac{3}{2}} A D^{\frac{1}{2}} C v^{\frac{1}{2}}

…”

Section: Resultsmentioning

confidence: 99%

Graphite/Nanocrystalline Zeolite Platform for Selective Electrochemical Determination of Hepatitis C Inhibitor Ledipasvir

et al. 2018

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“…The mismatches in the reverse scan reflect the background capacitance but capture exactly the lack of a back peak. The presence or absence of a reverse peak is dependent on a dimensionless kinetic rate constant

K_{2} = \frac{k_{f}}{v} (\frac{R T}{F}) {([], A)}_{b u l k}

, which is proportional to the analyte concentration (

{[A]}_{b u l k}

) and inversely proportional to the scan rate ( v ) for an EC 2 as mentioned before . From Figure at a such high concentration of 1.0 mM sulphite the loss of a back peak occurs for large K 2 .…”

Section: Resultsmentioning

confidence: 98%

“…This apparent value is close to unity, indicating that the process is seemingly likely a one‐electron transfer reversible reaction at first glance . However, the positive shift of potential with the increase of scan rate suggests a more complex process since for a simple pure reversible reaction the peak potential would be independent of scan rate .…”

Section: Resultsmentioning

confidence: 99%

The Electrochemical Oxidation of Sulphite on Gold Electrodes

et al. 2019

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The electro‐oxidation of sulphite is studied in acid media on gold macroelectrodes and Au particle array modified boron doped diamond electrodes. The sulphite oxidation proceeds through a one‐electron transfer process followed by a chemical step of second order (EC2 mechanism), as evidenced by experimental voltammetry and digital simulation for both gold macroelectrodes and gold particle modified substrates. The diffusion coefficient of sulphite is calculated consistently for both cases at about 4×10−9 m2 s−1, with the reverse peak behaviour concentration dependent. The arrays are made by electrodeposition and show a morphological transition from a quasi‐spherical to a star shape as the growth time of the particles increases. Kinetic parameters inferred from the electro‐oxidation at the macroelectrode can be successfully applied to model the gold particle modified electrode data to confirm the EC2 mechanism, whilst recognising the overlapping diffusion layers of adjacent gold particles.

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“…For a more sensitive quantification, differential pulse voltammetry (DPV) with a cathodic potential scanning was carried out in all experiments, due to the considerably enhanced electrochemical signal that was obtained as compared to cyclic voltammetry . The mechanism observed in the voltammetric preliminary study has been also confirmed by electrochemical impedance spectroscopy (EIS) measurements of GONC modified surface.…”

Section: Resultsmentioning

confidence: 99%

Electroactive Nanocarbon Can Simultaneously Work as Platform and Signal Generator for Label‐Free Immunosensing

2019

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Electroactive nanocarbon can be defined as a carbon nanomaterial that contains electrochemically reducible oxygen functionalities. We show here how an electroactive nanocarbon material can work both as a platform and as a signal generator when developing an immunosensor for the detection of mycotoxins. The suitability of the material for the immobilization of the biorecognition element by the formation of multiple noncovalent interactions, and the concurrent ability to provide a significant reduction peak are combined here in a label-free, single-step immunosensor. The variation in the current inten-sity, owing to the reduction of the electroactive platform, is correlated to the electrochemical availability of the oxygen functionalities involved in the interaction with the biorecognition element first, and the antibody/antigen conjugate in the detection step. We demonstrated here a direct dependence between the signal generated from the electroactive nanocarbon platform and each step of the biorecognition event, which allows the selective and precise detection of the analyte under investigation.

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Understanding Voltammetry

Cited by 141 publications

References 0 publications

Graphite/Nanocrystalline Zeolite Platform for Selective Electrochemical Determination of Hepatitis C Inhibitor Ledipasvir

Graphite/Nanocrystalline Zeolite Platform for Selective Electrochemical Determination of Hepatitis C Inhibitor Ledipasvir

The Electrochemical Oxidation of Sulphite on Gold Electrodes

Electroactive Nanocarbon Can Simultaneously Work as Platform and Signal Generator for Label‐Free Immunosensing

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