Amperometric glucose biosensors based on an osmium (2⁺/3⁺) redox polymer‐mediated electron transfer at carbon paste electrodes

Abstract

Four glucose sensors have been developed by modifying carbon paste electrodes with glucose oxidase as a biocomponent and a conducting redox osmium-polymer as the mediating compound. The enzyme was immobilized by crosslinking with glutaraldehyde and bovine serum albumin in three modifications of electrodes and physical adsorption in one electrode. The optimal concentrations of the modifying compounds were determined and the response of the sensors to 2-20 mM glucose were characterized. The influence of pH, temperature, interferences, and storage on the responses of the sensors were investigated.

Iridium‐dispersed carbon paste enzyme electrodes

“…Various avenues have been employed to impart higher selectivity onto carbon paste biosensors (in the absence of anti-interference layers). These include the use of non-physiological electron acceptors [2-41 or electron relays [5], and more recently of electrocatalytic metal-dispersed graphite particles [6]. In particular, rhodiumand ruthenium-dispersed carbon pastes offer a strong and preferential electrocatalytic action towards the enzymaticallyliberated hydrogen peroxide, but not towards coexisting oxidizable constituents [7,8].…”

Electrolyte Effects on Electrochemical Properties of Osmium Complex Polymer Modified Electrodes

“…4 [Os(bpy)2(PVI)10Cl]Cl and [Os(bpy)2(PVP)10Cl]Cl, where bpy is 2,2′-bipyridyl, PVI is poly(N-vinylimidazole), and PVP is poly(4-vinylpyridine), are two typical electron transfer mediators with a near-ideal electrochemical behavior, 5 which have been extensively used for the preparation of electrochemical enzyme sensors. [6][7][8][9][10][11] Modified electrodes based on these polymers show high electrochemical activity and can catalyze those reactions that are difficult for direct electron transfer, such as the electrochemical oxidations of epinephrine and dopamine, 6 ascorbic acid 7 and glucose. 8 After further crosslinking with enzymes, these modified electrodes have been designed for the determination of enzyme activity or their substrates 9,10 and as immunosensors.…”

“…[6][7][8][9][10][11] Modified electrodes based on these polymers show high electrochemical activity and can catalyze those reactions that are difficult for direct electron transfer, such as the electrochemical oxidations of epinephrine and dopamine, 6 ascorbic acid 7 and glucose. 8 After further crosslinking with enzymes, these modified electrodes have been designed for the determination of enzyme activity or their substrates 9,10 and as immunosensors. 11 However, the electrochemical behaviors of these metallopolymers are dependent on many factors, including the pH of the supporting electrolyte, electrolyte species, and solvent.…”

Carbon Paste Electrodes

“…of glucose with GOD, direct electron transfer [165] Abbreviations and symbols: detn., determination; e.g., for example; GOD, glucose oxidase; immob., immobilization; (MW)CNT(s), (multiwalled) carbon nanotubes; LA2, commercial denotation (abbreviation); NADH, nicotinamide adenine dinucleotide; and NAD + , oxidized form of NADH.…”