An Enzyme-Chemically Modified Carbon Paste Electrode as a Glucose Sensor Based on Glucose Oxidase Immobilized in a Polyaniline Film

Amperometric and impedimetric characterization of a glutamate biosensor based on Nafion® and a methyl viologen modified glassy carbon electrode

“…Viologens, derivatives of 4,4 -bipyridyl, continue to play an important role as electron relays in systems in which electron transfer is initiated by electrochemical processes (Johansen et al, 1992). They have been widely used as mediators for different amperometric enzyme biosensors such as glucose oxidase biosensors (Hu et al, 1999;Cen et al, 2003;Liu et al, 2004, Ghica and and nitrate reductase biosensors (Moretto et al, 1998;Glazier et al, 1998;Wang et al, 2006). Viologens are highly water soluble and very toxic.…”

Biomedical application of immobilized enzymes

“…In addition, the polyelectrolyte nature of the Nafion film can stabilize the ionic strength at the electrode surface, thereby preventing electrode fouling and increasing the dynamic range for analyte detection. Other polymer films, such as poly(vinyl alcohol),30 polytetrafluoroethylene,31 poly(vinyl alcohol) grafted 4‐vinylpyridine,32 poly(pyrrole‐ammonium)/poly(pyrrole‐lactobionamide),33 polyaniline,34 and poly( o ‐phenylenediamine)35 have also been used recently in preparing biosensors because of their advantageous properties of high oxygen solubility, decent hydrophilicity, good biocompatibility, reasonable mechanical strength, and anti‐fouling 36. In addition, immobilization of heparin on artificial surfaces has also been extensively explored in an attempt to create a thromboresistant surface for the use of the biosensors in vivo 37, 38…”

“…Another approach to solve this oxygen deficiency problem is to place a diffusion‐restriction membrane on top of the enzyme membrane. Such a diffusion‐limiting membrane will yield high oxygen permeability but low glucose permeability, thereby providing a minimal concentration of glucose within the enzyme layer and a relatively constant amount of oxygen 30–35. Alternatively, some artificial electron acceptors or mediators, such as ferrocenes,47 quinones,48 diaminobenzenes,49 and TTF,50 have also been used to minimize the sensitivity to oxygen of the enzyme‐based electrodes.…”

“…Such a diffusion-limiting membrane will yield high oxygen permeability but low glucose permeability, thereby providing a minimal concentration of glucose within the enzyme layer and a relatively constant amount of oxygen. [30][31][32][33][34][35] Alternatively, some artificial electron acceptors or mediators, such as ferrocenes, 47 quinones, 48 diaminobenzenes, 49 and TTF, 50 have also been used to minimize the sensitivity to oxygen of the enzymebased electrodes. These electron-transfer mediators, which are retained at the electrode surface using a membrane or entrapped in an electrongenerated film at the surface, facilitate electron transfer between an electrode and a redox-active biological molecule, ensuring the attainment of a high signal-to-noise ratio.…”

A glucose biosensor using methyl viologen redox mediator on carbon film electrodes

“…This interaction results in accumulation of MV 2+ in Nafion films [17]. Nafion-methyl viologen complexes in the matrix possess excellent catalytic activity for the electroreduction of oxygen, and have high permeability to oxygen, but limited permeability to potential interferents such as uric acid, ascorbic acid and cystine [20]. Carbon materials are widely used in electrochemistry as electrodes and as substrates for modified electrodes.…”