The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Rubin Gulaboski - One of the best experts on this subject based on the ideXlab platform.
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Voltammetry-Principles and Applications
2020Co-Authors: Rubin GulaboskiAbstract:Voltammetry is a potentiodynamic technique that is inevitable tool in everyday experiments in many physicochemical and biological laboratories. The principles, potential applications and the advantages/disadvantages of various voltammetric techniques are described.
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Square-wave Voltammetry of Ofloxacin
2020Co-Authors: Rubin Gulaboski, Blagoja JordanoskiAbstract:Adsorption phenomena of ofloxacin at a hanging mercury drop electrode in Britton Robinson buffer solution with pH of 8.36 were studied by means of square-wave Voltammetry.
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Differential Square-Wave Voltammetry.
Analytical Chemistry, 2019Co-Authors: Valentin Mirceski, Leon Stojanov, Dariusz Guziejewski, Rubin GulaboskiAbstract:A new voltammetric technique designed as a hybrid between differential pulse and square-wave Voltammetry is proposed for the purpose of unifying the advantages of both techniques, i.e., the ability to provide mechanistic information, studying electrode kinetics of both sluggish and very fast electrode reactions, and the ability to suppress effectively residual background current. Voltammetric modulation of the hybrid technique consists of a staircase potential combined with square-wave potential modulation superimposed at the end of each potential step. By measuring the current at the end of each potential step and pulse, differential forward and backward voltammetric components can be composed, which is a unique ability of the hybrid technique. In addition, by analogy to square-wave Voltammetry, a net differential component can be contracted with improved analytical performances compared to square-wave Voltammetry. The proposed technique opens a new avenue for an advanced analysis of electrochemical proc...
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Differential Square-Wave Voltammetry.
Analytical Chemistry, 2019Co-Authors: Valentin Mirceski, Leon Stojanov, Dariusz Guziejewski, Rubin GulaboskiAbstract:: A new voltammetric technique designed as a hybrid between differential pulse and square-wave Voltammetry is proposed for the purpose of unifying the advantages of both techniques, i.e., the ability to provide mechanistic information, studying electrode kinetics of both sluggish and very fast electrode reactions, and the ability to suppress effectively residual background current. Voltammetric modulation of the hybrid technique consists of a staircase potential combined with square-wave potential modulation superimposed at the end of each potential step. By measuring the current at the end of each potential step and pulse, differential forward and backward voltammetric components can be composed, which is a unique ability of the hybrid technique. In addition, by analogy to square-wave Voltammetry, a net differential component can be contracted with improved analytical performances compared to square-wave Voltammetry. The proposed technique opens a new avenue for an advanced analysis of electrochemical processes and analytical application.
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Voltammetry of Medical Biomaterials
2015Co-Authors: Rubin Gulaboski, Velo MarkovskiAbstract:The use of biomaterials in the medicine, dentistry and pharmacy represents probably a major breakthrough in tackling many diseases or disabilities in the last 50 years. We refer to varios techniques that are used for the characterization of the structure and the composition of the biomaterials. Voltammetry is an electrochemical technique that helps mainly in understanding the redox properties of various biomaterials containing some suitable redox centers in their structure. We give in this lecture insights about the application of Voltammetry in characterization of some biomaterials, while discussing the advantages and the potential for mechanistic, thermodynamic and kinetic characterizations with this technique.
Valentin Mirceski - One of the best experts on this subject based on the ideXlab platform.
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Differential Square-Wave Voltammetry.
Analytical Chemistry, 2019Co-Authors: Valentin Mirceski, Leon Stojanov, Dariusz Guziejewski, Rubin GulaboskiAbstract:A new voltammetric technique designed as a hybrid between differential pulse and square-wave Voltammetry is proposed for the purpose of unifying the advantages of both techniques, i.e., the ability to provide mechanistic information, studying electrode kinetics of both sluggish and very fast electrode reactions, and the ability to suppress effectively residual background current. Voltammetric modulation of the hybrid technique consists of a staircase potential combined with square-wave potential modulation superimposed at the end of each potential step. By measuring the current at the end of each potential step and pulse, differential forward and backward voltammetric components can be composed, which is a unique ability of the hybrid technique. In addition, by analogy to square-wave Voltammetry, a net differential component can be contracted with improved analytical performances compared to square-wave Voltammetry. The proposed technique opens a new avenue for an advanced analysis of electrochemical proc...
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Differential Square-Wave Voltammetry.
Analytical Chemistry, 2019Co-Authors: Valentin Mirceski, Leon Stojanov, Dariusz Guziejewski, Rubin GulaboskiAbstract:: A new voltammetric technique designed as a hybrid between differential pulse and square-wave Voltammetry is proposed for the purpose of unifying the advantages of both techniques, i.e., the ability to provide mechanistic information, studying electrode kinetics of both sluggish and very fast electrode reactions, and the ability to suppress effectively residual background current. Voltammetric modulation of the hybrid technique consists of a staircase potential combined with square-wave potential modulation superimposed at the end of each potential step. By measuring the current at the end of each potential step and pulse, differential forward and backward voltammetric components can be composed, which is a unique ability of the hybrid technique. In addition, by analogy to square-wave Voltammetry, a net differential component can be contracted with improved analytical performances compared to square-wave Voltammetry. The proposed technique opens a new avenue for an advanced analysis of electrochemical processes and analytical application.
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RECENT ADVANCES AND PROSPECTS OF SQUARE-WAVE Voltammetry
Contributions Section of Natural Mathematical and Biotechnical Sciences, 2018Co-Authors: Valentin Mirceski, Leon Stojanov, Sławomira SkrzypekAbstract:This review concerns recent methodological advances of square-wave Voltammetry as one of the most sophisticated members of the pulse voltammetric techniques. Besides addressing recent theoretical works and representatives of advanced analytical studies, an emphasis is given to a few novel methodological concepts such as kinetic analysis at constant scan rate, cyclic square-wave Voltammetry, multisampling square-wave Voltammetry, and electrochemical faradaic spectroscopy. For the purpose of improving analytical performances of the technique two new methods are proposed for the first time.
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Square-wave Voltammetry
ChemTexts, 2018Co-Authors: Valentin Mirceski, Sławomira Skrzypek, Leon StojanovAbstract:This text is written as a very basic, first introduction to square-wave Voltammetry, as one of the very specific, but most versatile techniques in the family of pulse voltammetric techniques. To make the text self-consistent, a brief introduction to Voltammetry is initially given, to make the next elaboration of square-wave Voltammetry more easily understandable. For more comprehensive introduction to voltammetric techniques, the previous chem-text is recommended (Scholz in ChemTexts 1:17, 2015). The aim of the current text is to explain the basic features of square-wave Voltammetry, to reveal the essential idea behind the specific shape of the excitation signal used, as well as to demonstrate that square-wave Voltammetry is highly suited to study the mechanism of electrode reactions. The latter is illustrated by addressing the simplest experimental situation encountered in Voltammetry to make the text didactically suited for broader student population studying chemistry and related sciences.
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RECENT ACHIEVEMENTS IN SQUARE-WAVE Voltammetry (A REVIEW)
Macedonian Journal of Chemistry and Chemical Engineering, 2014Co-Authors: Valentin Mirceski, Rubin GulaboskiAbstract:Recent advances in square-wave Voltammetry for analytical purposes as well as for studying electrode mechanisms and kinetics are reviewed, mainly covering results published in the last decade. Analyzing only some typical analytically oriented studies, one confirms the well-known fact that the technique is attributed with superior analytical performance in the family of advance pulse voltammetric techniques. Covering all analytical studies where square-wave Voltammetry is the working technique is hardly possible. For this reason, we decided to cover the relevant studies in square-wave Voltammetry, mainly published in the last five to seven years. The reviewed period is marked with remarkable contributions in the theory of complex electrode mechanisms, revealing that square-wave Voltammetry is one of the most powerful voltammetric techniques for both mechanistic and kinetic characterizations of electrode processes. Finally, a brief consideration is given to several methodologically oriented studies, referring mainly to cyclic-square Voltammetry as well as methods based on the analysis of electrode processes by varying the amplitude of the potential modulation, which is expected to expand the scope and application of the technique in coming years.
Richard G. Compton - One of the best experts on this subject based on the ideXlab platform.
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Voltammetry of porous layers: Staircase vs analog Voltammetry
Journal of Electroanalytical Chemistry, 2016Co-Authors: Enno Kätelhön, Richard G. ComptonAbstract:Abstract The use of staircase ramps for cyclic Voltammetry rather than true linear analog ramps can lead to significant misinterpretation of the signals recorded for the measurement of diffusional redox species with either reversible or irreversible electrode kinetics measured at electrodes modified with porous layers. Most notably a large perturbation of the expected peak current is apparent which can preclude the extraction of meaningful data, for example in respect of surface coverages or in the identification of electro-catalysis.
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recent advances in Voltammetry
ChemistryOpen, 2015Co-Authors: Christopher Batchelormcauley, Enno Kätelhön, Richard G. Compton, Edward O Barnes, Eduardo Laborda, Ángela MolinaAbstract:Recent progress in the theory and practice of Voltammetry is surveyed and evaluated. The transformation over the last decade of the level of modelling and simulation of experiments has realised major advances such that electrochemical techniques can be fully developed and applied to real chemical problems of distinct complexity. This review focuses on the topic areas of: multistep electrochemical processes, Voltammetry in ionic liquids, the development and interpretation of theories of electron transfer (Butler–Volmer and Marcus–Hush), advances in voltammetric pulse techniques, stochastic random walk models of diffusion, the influence of migration under conditions of low support, Voltammetry at rough and porous electrodes, and nanoparticle electrochemistry. The review of the latter field encompasses both the study of nanoparticle-modified electrodes, including stripping Voltammetry and the new technique of ‘nano-impacts’.
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the use of nano carbon as an alternative to multi walled carbon nanotubes in modified electrodes for adsorptive stripping Voltammetry
Sensors and Actuators B-chemical, 2012Co-Authors: Tsz W B Lo, Leigh Aldous, Richard G. ComptonAbstract:Abstract We report the advantageous use of nano-carbon black as a much cheaper alternative to multiwalled carbon nanotubes as an electrode modifier for use in adsorptive stripping Voltammetry. Namely, the adsorptive stripping Voltammetry (AdsSV) of nicotine is compared and contrasted at an unmodified glassy carbon (GC) electrode and GC electrodes modified with either bamboo multiwalled carbon nanotubes (MWCNT) or carbon black. The approximately spherical, primary carbon black particles used possessed an average radius of 7 nm, and are a form of ‘nano-carbon’. Their immobilisation on a GC resulted in a nanostructured surface with a large active surface area. Cyclic Voltammetry (CV), Square Wave Voltammetry (SWV) and Differential Pulse Voltammetry (DPV) were performed using the various systems. SWV resulted in a Limit of Detection (LOD) of 12.4 ± 0.2 μM at bare GC. CV gave the lowest LOD results for MWCNT and nano-carbon modified electrodes, with LOD values of 5.0 ± 0.3 and 2.0 ± 0.3 μM. Nano-carbon is highlighted to be a cheap, highly effective electrode modifier which facilitates the electroanalytical quantification of physiologically relevant concentrations of nicotine by AdsSV.
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Voltammetry at spatially heterogeneous electrodes
Journal of Solid State Electrochemistry, 2005Co-Authors: Trevor J Davies, Craig E Banks, Richard G. ComptonAbstract:Recent advances are overviewed which enable simulation of the voltammetric behaviour of surfaces which respond in an electrochemically spatially heterogeneous fashion. By use of the concept of a “diffusion domain” computationally expensive three-dimensional simulations may be reduced to tractable two-dimensional equivalents. In this way the electrochemical response of partially blocked electrodes and microelectrode arrays may be predicted, and are found to be consistent with experimental data. It is, furthermore, possible to adapt the “blocked” electrode analysis to enable the voltammetric sizing of inert particles present on an electrode surface. Finally theory of this type predicts the voltammetric behaviour of electrochemically heterogeneous electrodes—for example composites whose different spatial zones display contrasting electrochemical behaviour toward the same redox couple.
Artur Cavaco-paulo - One of the best experts on this subject based on the ideXlab platform.
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Staining of wool using the reaction products of ABTS oxidation by Laccase: Synergetic effects of ultrasound and cyclic Voltammetry
Ultrasonics Sonochemistry, 2007Co-Authors: Florentina-daniela Munteanu, G. M. Gübitz, Carlos Basto, Artur Cavaco-pauloAbstract:The effects of ultrasound on 2,2???-Azinobis(3-ethylbenzothiazoline-6-sulfonate) enzymatic oxidation by laccase (Trametes villosa) has been studied by means of cyclic Voltammetry. The reaction was allowed to proceed in the presence of a piece of wool and the coloration depth of the wool fabric was measured by means of K/S. It was observed that cyclic Voltammetry is influenced the dyeing process and higher K/S values were obtained when the cyclic Voltammetry was combined with the ultrasonic irradiation. Moreover, the K/S value is the sum of the values obtained when the wool staining is done in just the presence of cyclic Voltammetry or in just the presence of ultrasound. The results obtained on the indigo carmine decolourization gives information on the importance of controlling the amount of ABTS{radical dot}+ formed during the ultrasonication process. ?? 2006 Elsevier B.V. All rights reserved.
Janet Osteryoung - One of the best experts on this subject based on the ideXlab platform.
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Determination of sodium and other impurities in alkoxysilanes by square-wave Voltammetry
Analytica Chimica Acta, 1992Co-Authors: Shigeru Saito, Janet OsteryoungAbstract:Abstract The determination of sodium concentration in acetonitrile and in acetonitrile-alkylalkoxysilane mixtures was investigated by using the static mercury drop electrode and square-wave Voltammetry. Direct square-wave Voltammetry was used over the range 10–100 μM Na+, and square-wave anodic stripping Voltammetry was used in the range 1–10 μM Na+. The detection limit in the anodic stripping mode was found to be 0.3 μM. Further, the behavior of impurities in acetonitrile-alklalkoxysilane mixtures was investigated qualitatively.
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Pulse Voltammetry at microcylinder electrodes.
Analytical Chemistry, 1991Co-Authors: Mary M. Murphy, Janet OsteryoungAbstract:: Microcylindrical electrodes are easier to construct and maintain than microdisk electrodes. In the normal-pulse mode, ranges of time parameters and electrode sizes can be found such that depletion of reactant is unimportant and the response to the analysis pulse is predicted by theory for planar conditions. Similarly, ranges of parameters are found for reverse-pulse Voltammetry such that the potential-dependent response can be treated as a sequence of individual double-pulse responses. Cylindrical diffusion and convection act to replenish reactant quickly near the electrode and thus permit overall experiment times in the range of seconds. For square-wave Voltammetry the shape and position of the net current response are independent of the extent of cylindrical diffusion.
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Square-Wave and Staircase Voltammetry at Small Electrodes
Microelectrodes: Theory and Applications, 1991Co-Authors: Janet OsteryoungAbstract:Square-wave and staircase Voltammetry at small electrodes constitute dynamic experiments in which a train of pulses is applied at a stationary electrode. The response thus depends in a complex way on the size and shape of the electrode as well on the parameters of the excitation. The most striking feature of the response is that in square-wave Voltammetry the peak shape and position are largely independent of the size and shape of the electrode for reversible systems. Attributes of square-wave and staircase Voltammetry are illustrated for embedded circular and for cylindrical electrodes, and for arrays. Applications in which nonplanar diffusion is an important aspect include anodic stripping Voltammetry and mechanistic studies.
