The cyclic and linear sweep voltammetry of regular and random arrays of microdisc electrodes: Theory

Davies, Trevor J.; Compton, Richard G.

doi:10.1016/j.jelechem.2005.07.022

Cited by 367 publications

(421 citation statements)

References 26 publications

(62 reference statements)

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“…Since the first studies on NEEs [1,30], it was indeed demonstrated that these ensembles of nanodisk electrodes behave as electrodes with partially blocked surface [31], for which the true heterogeneous kinetic constant is substituted by an apparent one, the latter being smaller by a factor which corresponds to the fractional electrode area, that is the ratio between active and geometric area [1,30]. The validity of such a model was confirmed also by more recent theoretical studies [32][33][34][35]. The dashed and dotted lines in Fig.…”

Section: Redox Probes At Sam Modified Neesmentioning

confidence: 74%

Modification of nanoelectrode ensembles by thiols and disulfides to prevent non specific adsorption of proteins

Silvestrini

Schiavuta²,

Scopece³

et al. 2011

Electrochimica Acta

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a b s t r a c tThe possibility to functionalize selectively with thiols or disulfides the surface of the gold nanoelectrodes of polycarbonate templated nanoelectrode ensembles (NEEs) is studied. It is shown that the Au nanoelectrodes can be coated by a self assembled monolayer (SAM) of thioctic acid (TA) or 2-mercaptoethanesulfonic (MES) acid. The study of the electrochemical behavior of SAM-modified NEEs by cyclic voltammetry (CV) at different solution pH, using ferrocenecarboxylate as an anionic redox probe (FcCOO − ) and (ferrocenylmethyl)trimethylammonium (FA + ) as a cationic redox probe, demonstrate that the SAM-modified nanoelectrodes are permselective, in that only cationic or neutral probes can access the SAM-coated nanoelectrode surface. CV, AFM and FTIR-ATR data indicate that proteins such as casein or bovine serum albumin, which are polyanionic at pH 7, adsorb on the surface of NEEs untreated with thiols, tending to block the electron transfer of the ferrocenyl redox probes. On the contrary, the pretreatment of the NEE with an anionic SAM protects the nanoelectrodes from protein fouling, allowing the detection of well shaped voltammetric patterns for the redox probe. Experimental results indicate that, in the case of MES treated NEEs, the protein is bound only onto the polycarbonate surface which surrounds the nanoelectrodes, while the tips of the gold nanoelectrodes remain protein free.

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Section: Redox Probes At Sam Modified Neesmentioning

confidence: 74%

Modification of nanoelectrode ensembles by thiols and disulfides to prevent non specific adsorption of proteins

Silvestrini

Schiavuta²,

Scopece³

et al. 2011

Electrochimica Acta

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“…To this end, we simulate the effects of altering inter-electrode separations on analyte diffusion for a range of scan rates at nanowire electrode arrays, and perform the corresponding experiments. We show that arrays with 15 diffusionally independent concentration profiles demonstrate superior electrochemical performance compared to arrays with overlapping diffusion profiles when employing sweep voltammetric techniques. By contrast, we show that arrays with diffusionally overlapping profiles exhibit enhanced performance when employing step voltammetric techniques.…”

Section: Faraday Discussionmentioning

confidence: 95%

“…macroelectrodes), while an ideal steady-state and time-independent response (radial diffusion) is typical of much smaller electrodes (e.g. ultramicroelectrodes) [3,15]. 75 At present, there is no analytical equation to describe diffusion to an electrode geometry where an electrode has sharp edges and protrudes from a planar substrate, i.e., a nanowire.…”

Section: Introductionmentioning

confidence: 99%

“…For a nanowire r 0 = w/4 where, w is the width of the electrode [16][17][18]. In this manner diffusion independence is theoretically maintained by ensuring that the separation between neighbouring electrodes, s, is greater than twice the diffusion 15 thickness (s > 2δ). However, we and others have recently shown that this is not the case at the nanoscale and significantly larger separations are required to maintain diffusional independence between neighbouring electrodes and this separation is significantly affected by applied scan-rate [14,19].…”

Section: Introductionmentioning

confidence: 99%

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Gold nanowire electrodes in array: simulation study and experiments

et al. 2013

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Type of publicationArticle ( Accepted ManuscriptThis is an Accepted Manuscript, which has been through the RSC Publishing peer review process and has been accepted for publication.Accepted Manuscripts are published online shortly after acceptance, which is prior to technical editing, formatting and proof reading. This free service from RSC Publishing allows authors to make their results available to the community, in citable form, before publication of the edited article. This Accepted Manuscript will be replaced by the edited and formatted Advance Article as soon as this is available.To cite this manuscript please use its permanent Digital Object Identifier (DOI®), which is identical for all formats of publication.More information about Accepted Manuscripts can be found in the Information for Authors.Please note that technical editing may introduce minor changes to the text and/or graphics contained in the manuscript submitted by the author(s) which may alter content, and that the standard Terms & Conditions and the ethical guidelines that apply to the journal are still applicable. In no event shall the RSC be held responsible for any errors or omissions in these Accepted Manuscript manuscripts or any consequences arising from the use of any information contained in them. www.rsc.org/faraday_d Faraday Discussions Vol 161Lipids & Membrane Biophysics Faraday DiscussionsThis manuscript will be presented and discussed at a forthcoming Faraday Discussion meeting. All delegates can contribute to the discussion which will be included in the final volume. voltammograms even at very high scan rates (5000 mV.s -1 ) indicative of fast analyte mass transport to the electrode. Nanowire electrode arrays offer the potential for enhancements in electroanalysis including: increased signal to noise ratio and increased sensitivity while also allowing quantitative detection at much lower concentrations. However, to achieve this goal a full understanding of the diffusion profiles existing at nanowire arrays is required. To this end, we simulate the effects of altering inter-electrode separations on analyte diffusion for a range of scan rates at nanowire electrode arrays, and perform the corresponding experiments. We show that arrays with 15 diffusionally independent concentration profiles demonstrate superior electrochemical performance compared to arrays with overlapping diffusion profiles when employing sweep voltammetric techniques. By contrast, we show that arrays with diffusionally overlapping profiles exhibit enhanced performance when employing step voltammetric techniques. Register now to attend!

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“…[31][32][33] From their work, the voltammogram of the bare Au arises from pure linear diffusion, characteristic of category 1 (naked electrode). The CVs of the modified electrodes describe the behaviour typical of ''micro-sized'' electro-active zones that are separated with inert blocking materials such that the electrode as a whole behaves like a collection of isolated microelectrodes, each of which experiencing covergent or radial diffusion that may lead to either type 2 or type 3 phenomenon.…”

Section: Cyclic Voltammetry Characterisationmentioning

confidence: 99%

Electron transfer dynamics across self-assembled N-(2-mercaptoethyl) octadecanamide/mycolic acid layers: impedimetric insights into the structural integrity and interaction with anti-mycolic acid antibodies

Ozoemena

Mathebula

Pillay

et al. 2010

Phys. Chem. Chem. Phys.

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The integrity and properties of mycolic acid (MA) antigens integrated into a self-assembled monolayer (SAM) of N-(2-mercaptoethyl)octadecanamide, (MEODA), on a gold electrode have been interrogated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). EIS data showed that Au-MEODA and Au-MEODA-MA behave as microelectrode arrays, with pinholes acting as the microelectrodes that permit electron transport between a redox-active probe in solution and the underlying gold surface. The average radii of the pinholes (r a ) and half the distance between the centers of the neighbouring pinholes (r b ), were estimated from EIS using the pore size model, and discussed. Anti-MA antibodies present in a tuberculosis (TB)-infected patient (co-infected with HIV) strongly interact with Au-MEODA-MA showing a rather compact and stable bio-complex structure that is virtually defect-free. The electrochemical impedimetric properties associated with the ability of the Au-MEODA-MA to discriminate between TB positive and negative human sera are also discussed. We prove that the Au-MEODA and Au-MEODA-MA electrodes, as well as the MA-anti-MA antibody interactions, are characterized with time-constant dispersion, typical of microstructures with grain/grain boundary phases. These crucial physico-electrochemical insights into the behaviour of surface-confined MA should provide a useful basis for the design and development of a potential impedimetric immunosensing platform for active tuberculosis.

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The cyclic and linear sweep voltammetry of regular and random arrays of microdisc electrodes: Theory

Cited by 367 publications

References 26 publications

Modification of nanoelectrode ensembles by thiols and disulfides to prevent non specific adsorption of proteins

Modification of nanoelectrode ensembles by thiols and disulfides to prevent non specific adsorption of proteins

Gold nanowire electrodes in array: simulation study and experiments

Electron transfer dynamics across self-assembled N-(2-mercaptoethyl) octadecanamide/mycolic acid layers: impedimetric insights into the structural integrity and interaction with anti-mycolic acid antibodies

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