Amperometric determination of ascorbic acid at a ferricyanide-doped Tosflex-modified electrode

Zen, Jyh‐Myng; Tsai, Dong‐Mung; Kumar, Annamalai Senthil; Dharuman, Venkataraman

doi:10.1016/s1388-2481(00)00121-1

Cited by 54 publications

(24 citation statements)

References 19 publications

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“…for AA mediated oxidation reactions [75]. The advantage over classical PVP film is that Tosflex can load Fe(CN) 6 3À in a pH window of 2 ± 12 while the PVP is restricted up to pH 4 [123 ± 125] only.…”

Section: àmentioning

confidence: 99%

Recent Updates of Chemically Modified Electrodes in Analytical Chemistry

2003

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This review article updates recent developments in chemically modified electrodes (CMEs) towards analytical applications for the year of 2000 ± 2002 with 179 references. The broad topics are subdivided into four main categories: i) physisorption/chemisorption, ii) covalently linked, iii) homogenous (uniform) multilayer and iv) heterogeneous (non-uniform) multilayer CMEs. The criteria for the preparation of CMEs in elecrocatalytic systems are clearly described in Section 1. Some of the encouraging results related to Au-nanoparticles for DNA detection and new ceramic carbon, carbon nanotubes, copper-plated screen-printed and Nafion/lead ruthenate pyrochlore CMEs for catalytic application were especially discussed in this review.

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Section: àmentioning

confidence: 99%

Recent Updates of Chemically Modified Electrodes in Analytical Chemistry

2003

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“…Unfortunately, the limited working pH range (pH < 3) of poly(4-vinylpyridine) with considerable leakage of mediator restricts it to real-time application. Our group further improved the working pH range to cover the physiological condition using a Fe(CN) 3À 6 -doped Tosflexmodified glassy carbon electrode (designated as FDTME) for the mediated oxidation of ascorbic acid [8]. The FDTME is relatively stable under stationary solution phase condition, however, under hydrodynamic condition; it showed a remarkable foul-off behavior.…”

Section: Introductionmentioning

confidence: 99%

Flow Injection Analysis of Ascorbic Acid in Real Samples Using a Highly Stable Chemically Modified Screen‐Printed Electrode

2003

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A silica sol-gel glass-coated ferricyanide-doped Tosflex-modified screen-printed electrode (designated as SG/FeCNTs/SPE) was used for the mediated oxidation of ascorbic acid in neutral pH. The sol-gel overlayer was found to stabilize the Fe(CN) 3À 6 -Tosflex system without any foul-off and deterioration behavior through chemical interaction between the hydrophilic sites of Tosflex and oxy-and/or -hydroxy surface functional groups of silicate. The electrochemical mediation of ascorbic acid was found to follow the Michaelis-Menten kinetic pathway. The SG/FeCNTs/SPE was very stable for repetitive measurements by flow injection analysis at 0.3 V (vs. Ag/AgCl). A linear calibration plot was obtained for ascorbic acid determination up to 300 mM with sensitivity and detection limit (S/N 3) of 2.85 nA/mM and 46 nM, respectively. The system also showed tolerable interference to uric acid, urea and carbohydrates and was used for the determination of ascorbic acid in human urine, clinical tablet and apple juice.

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“…Organic electro-oxidation at conductive hydrated metal oxide surfaces provides another example [29] . In more recent publications biphasic kinetic data are reported for glucose oxidation at thin electropolymerized poly(phenol) films containing immobilized glucose oxidase [30] and at alkanethiol self assembled monolayers containing adsorbed glucose oxidase [31] , and for both NADH [32] and ascorbate [33] oxidation at poly(aniline)/poly(vinylsulfonate) composite modified electrodes and ascorbate oxidation at an electrode modified by a Tosflex ionomer film containing ferricyanide [34].…”

Section: A Precursor/successor and Complex Formation/dissociation Modelmentioning

confidence: 99%

Mediated Electron Transfer at Redox Active Monolayers. Part 3: Bimolecular Outer-Sphere, First Order Koutecky-Levich and Adduct Formation Mechanisms

Lyons¹

2002

Sensors

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A number of theoretical models describing the transport and kinetic processes involved in heterogeneous redox catalysis of solution phase reactants at electrode surfaces coated with redox active monolayers (such as self assembled alkane thiols containing a ferrocene group) is presented. These models are : simple bimolecular outer-sphere, generalized Koutecky-Levich, and substrate binding/ adduct formation . For each model a general expression for the steady state reaction flux is derived. Simplified analytical expressions for the net reaction flux under steady state conditions, are derived for experimentally reasonable situations, and kinetic case diagrams are constructed outlining the relationships between the various approximate solutions. The theory developed enables simple diagnostic plots to be constructed which can be used to analyse experimental data.

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Amperometric determination of ascorbic acid at a ferricyanide-doped Tosflex-modified electrode

Cited by 54 publications

References 19 publications

Recent Updates of Chemically Modified Electrodes in Analytical Chemistry

Recent Updates of Chemically Modified Electrodes in Analytical Chemistry

Flow Injection Analysis of Ascorbic Acid in Real Samples Using a Highly Stable Chemically Modified Screen‐Printed Electrode

Mediated Electron Transfer at Redox Active Monolayers. Part 3: Bimolecular Outer-Sphere, First Order Koutecky-Levich and Adduct Formation Mechanisms

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