A reagentless glucose biosensor based on glucose oxidase entrapped into osmium-complex modified polypyrrole films

Reiter, Sabine; Habermüller, Katja; Schuhmann, Wolfgang

doi:10.1016/s0925-4005(01)00861-9

Cited by 88 publications

(41 citation statements)

References 29 publications

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“…On bare Pt and GC (Fig. 9), the E m values for H 2 0 2 oxidation are 0.25 V and > 0.65 V, respectively, close to the values reported in previous work (0.19 V and 0.7 V, [62]). For the IrOx coated substrates, Figure 9 shows that the H 2 0 2 oxidation waves at both Pt/IrOx and GC/lrOx overlap with the IrOx peaks.…”

Section: H 2 0 2 Oxidation At S/irox Filmssupporting

confidence: 89%

“…The observed effect of the substrate material, based on well-documented [62] significant differences in the activities of Pt and GC surfaces towards H 2 0 2 oxidation and reduction, was used previously [63] to prove that glucose oxidation was being mediated by Ru poly(pyridine) complexes immobilized in a |3-cyclodextrin polymer. In the present work, the comparison of the H 2 0 2 redox reactions on metallic Ir and on IrOx films formed on bulk Ir, and other Electroanalysis 2004.…”

Section: Full Papermentioning

confidence: 99%

“…In the present work, two electrode materials, Pt and GC, were selected to establish the impact of the IrOx substrate on the H 2 0 2 reactions. These were chosen for its known significantly different [62,63] catalytic impact on H 2 0 2 redox reactions. Figure 8 shows the cyclic voltammograms of IrOx films, formed by the complete electrochemical conversion of Ir sols which were deposited in an identical fashion on Pt (solid line) and GC (dashed line), forming Pt/ IrOx and GC/IrOx electrodes, respectively.…”

Section: Formation and Characteristics Of S/irox Filmsmentioning

confidence: 99%

“…-0.1 V, Table 1). The fact that, due to kinetic limitations, the redox reactions of H 2 0 2 on GC occur at high overpotentials has been used recently [66] in a reagentless glucose sensor based on GOx entrapped into osmium complex modified poly- (pyrrole) films to prevent co-oxidation of enzymatically generated H 2 0 2 in the presence of molecular oxygen. The role of the substrate and lack of impact of the IrOx film on the reductive detection of H 2 0 2 is also clearly seen when the current sensitivities (in uA mrVF 1 cirr 2 ) for the bare substrates (S = Pt, Ir and GC) are compared with the S/ IrOx electrodes in Table 2.…”

Section: H 2 0 2 Reduction At S/irox Filmsmentioning

confidence: 99%

“…These results indicate that the oxidation of the mediator and of H 2 0 2 occur simultaneously on the electrode, with a preference for H 2 0 2 oxidation when the underlying electrode substrate is Pt vs. GC. Another example [62] of the use of GC, instead of Pt, in monitoring the response of a reagentless glucose sensor, is based on glucose oxidase entrapped in osmium complexmodified poly(pyrrole) films to prevent the concurrent oxidation of enzymatically generated H 2 0 2 in the presence of oxygen.…”

Section: H 2 0 2 Oxidation At S/irox Filmsmentioning

confidence: 99%

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Hydrogen Peroxide Detection at Electrochemically and Sol‐Gel Derived Ir Oxide Films

et al. 2004

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Ir oxide (IrOx) films, formed electrochemically on bulk Ir metal (Ir/IrOx) and also on sol‐gel (SG) derived non‐silica based nanoparticulate Ir, have been studied as material useful for the detection of hydrogen peroxide, with possible application as a glucose biosensor. H2O2 reduction and oxidation on Ir/IrOx and SG‐derived IrOx films, deposited on various substrates such as Pt, Ir and GC, have been compared to the H2O2 behavior at the bare substrate. It was found that H2O2 reduction proceeds on the underlying electrode substrate, while H2O2 oxidation is independent of the nature of the substrate, therefore occurring via the IrOx film. The reactivity of IrOx towards H2O2 oxidation is similar to that seen at Pt, although IrOx has the additional advantages of excellent stability, insensitivity to common interfering substances, biocompatibility and a linear range of detection, up to at least 12 mM H2O2. At micromolar concentrations of H2O2, a second mode of detection, involving the catalyzed growth of IrOx films at Ir substrates, can be employed. These two methods of H2O2 analysis (oxidation/reduction and enhanced IrOx growth) can also be employed for glucose detection using IrOx‐based glucose biosensors.

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Section: H 2 0 2 Oxidation At S/irox Filmssupporting

confidence: 89%

Section: Full Papermentioning

confidence: 99%

Section: Formation and Characteristics Of S/irox Filmsmentioning

confidence: 99%

Section: H 2 0 2 Reduction At S/irox Filmsmentioning

confidence: 99%

Section: H 2 0 2 Oxidation At S/irox Filmsmentioning

confidence: 99%

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Hydrogen Peroxide Detection at Electrochemically and Sol‐Gel Derived Ir Oxide Films

et al. 2004

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Catalytic Surfaces for Electroanalysis

Cox

Kulesza

2009

Encyclopedia of Analytical Chemistry

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In this article, electrochemical determinations based on oxidation or reduction processes that require a catalyst to obtain a current proportional to analyte concentration are described. The scope is restricted to cases where the catalyst is immobilized at the electrode surface. In general, oxidation or reduction of a substance at an electrode surface can be the basis of an analytical method as long as the electron‐transfer reaction occurs in the potential window between redox of the solvent, supporting electrolyte, and/or the electrode material. The need for a catalyst arises because only a small fraction of solutes that are predicted on the basis of standard potentials to undergo redox in an available potential window are electrolyzed in the absence of a catalyst at a sufficient rate to provide an analytically useful current. As described later, the common mode of promotion of the rate of electron transfer is by mediation. A problem that results when immobilized mediators are used is that the potential at which the current is produced is related to the mediator as well as to the analytes; hence, many practical applications of catalytic surfaces involve electrochemical detection after separation by methods such as high‐performance liquid chromatography (HPLC).

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