Theoretical and practical limitations on the optimization of amperometric detectors

Elbicki, J. M.; Morgan, Donald M.; Weber, Stephen G.

doi:10.1021/ac00270a026

Cited by 126 publications

(78 citation statements)

References 27 publications

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“…Furthermore, as pointed out by several reports, for different electrode geometries, i ss increases linearly with ν 1/3 . [29][30][31][32][33] This dependence was also observed in our experimental analysis (data not shown). Finally, to emphasize the outer-sphere nature of this redox reaction, EIS scans like the one shown in Figure 2D were performed.…”

Section: Figuresupporting

confidence: 85%

Delayed voltammetric with respect to amperometric electrochemical detection of concentration changes in microchannels

Trouillon

Gijs

2014

Lab Chip

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ARTICLEThis journal is © The Royal Society of Chemistry 2013 J. Name., 2013, 00, 1-3 | 1 The time response of an electrode incorporated into a fluidic channel to variations in analyte concentration of the outer-sphere redox probe ferrocenemethanol was investigated, both for amperometry (AMP) and cyclic voltammetry (CV). The experimental data show that the temporal resolution of CV is not as good as for AMP, as CV cannot properly detect fast concentration transients. The delayed response of CV was previously reported, for neurotransmitters, and mostly attributed to adsorption of the analyte to the electrode surface. By using an outer-sphere redox couple, we show that mass transport also significantly delays the response of CV. The experimental delay time in CV was understood from mass transfer limitations due to the relaxation of the diffusion layer during repeated potential scanning. Furthermore, a robust protocol for the analysis of fast concentration transients was established, using the impulse and modulation transfer functions of the system. This method was found to be more precise than the mere analysis of the undifferentiated traces in the time domain. As a proof of concept, the effect of increased viscosity was investigated, showing that AMP was more sensitive than CV to these variations. Overall, this analysis underlines further the enhanced temporal sensitivity of AMP over CV, at the expense of decreased chemical resolution, potentially having implications for in situ electrochemical detection of biologically relevant molecules.

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Section: Figuresupporting

confidence: 85%

Delayed voltammetric with respect to amperometric electrochemical detection of concentration changes in microchannels

Trouillon

Gijs

2014

Lab Chip

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“…This is not what would be expected for a diffusion controlled process [16]. However, in previous studies with rotating-disk electrodes it was already found that the oxidation of glucose at the modified electrodes is at least partially controlled by reaction kinetics [15].…”

Section: Flow Injection Analysis and Liquid Chromatographymentioning

confidence: 73%

Determination of sugars by liquid chromatography and amperometric detection with a cuprous oxide modified electrode

1995

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Determination of sugars by liquid chromatography and amperometric detection with a cuprous oxide modified electrode Huang, X.; Pot, J.J.; Kok, W.T. Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. SummaryA chemically modified electrode was applied as a working electrode for the amperometric detection of sugars in liquid chromatography. A mixture of cuprous oxide and conductive carbon cement was used as electrode material. Cuprous oxide acted as a catalyst for the oxidation of sugars. Cyclic voltammetry was used to examine the oxidation of the sugars at the electrode surface. The stability and sensitivity of a cuprous oxide/conductive carbon cement (20/80 %, w/w) electrode were tested in flow injection analysis experiments. For liquid chromatography, sugars were separated on an ion-exclusion column with 0.01 M H2SO4 as mobile phase. After the separation, 0.2 M NaOH was added post-column and the sugars were determined at 550 mV vs. Ag/AgC1. Calibration was linear in the range of 10 -6. 10 -3 M with limits of detection of approximately 1 9 10 .6 M. The application of the modified electrode for the determination of sugars in fruit beverages and dairy products following chromatographic separation is shown.

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“…According to M. Elbicki and co-authors [5] equation 1 could be presented as: the electrode with open tube geometry [6,7] as well as for the metal wire in tube type electrode [8].…”

Section: Continuous-flow Measurements At Potentiostatic Regimementioning

confidence: 99%

Flow-injection analysis with a small cylindrical wire type electrode

Denchev

Nikolov

2004

Open Chemistry

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Theoretical and practical limitations on the optimization of amperometric detectors

Cited by 126 publications

References 27 publications

Delayed voltammetric with respect to amperometric electrochemical detection of concentration changes in microchannels

Delayed voltammetric with respect to amperometric electrochemical detection of concentration changes in microchannels

Determination of sugars by liquid chromatography and amperometric detection with a cuprous oxide modified electrode

Flow-injection analysis with a small cylindrical wire type electrode

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