Hydrogen peroxide carbon paste electrode

XOD is one of the most complex flavoproteins and is composed of two identical and catalytically independent subunits each subunit contains one molybdenium center, two iron sulfur centers, and flavine adenine dinucleotide. The enzyme activity is due to a complicated interaction of FAD, molybdenium, iron, and labile sulfur moieties at or near the active site [260], It can be used to detect xanthine and hypoxanthine by immobilizing xanthine oxidase on a glassy carbon paste electrode [261], The elements are based on the chronoamperometric monitoring of the current that occurs due to the oxidation of the hydrogen peroxide which liberates during the enzymatic reaction. The biosensor showed linear dependence in the concentration range between 5.0 X 10 7 and 4.0 X 10-5M for xanthine and 2.0 X 10 5 and 8.0 X 10 5M for hypoxanthine, respectively. The detection limit values were estimated as 1.0 X 10 7 M for xanthine and 5.3 X 10-6M for hypoxanthine, respectively. Li used DNA to embed xanthine oxidase and obtained the electrochemical response of FAD and molybdenum center of xanthine oxidase [262], Moreover, the enzyme keeps its native catalytic activity to hypoxanthine in the DNA film. So the biosensor for hypoxanthine can be based on... 

Q.L. Wang, G.X. Lu, and B.J. Yang, Hydrogen peroxide biosensor based on direct electrochemistry of haemoglobin immobilized on carbon paste electrode by a silica sol-gel film. Sens. Actuators, B Chem. 99, 50-57 (2004). 

R. Garjonyte and A. Malinauskas, Electrocatalytic reactions of hydrogen peroxide at carbon paste electrodes modified by some metal hexacyano-ferrates, Sens. Actuators B, 46 (1998) 236-241. 

A similar approach was used for the detection of monosaccharides [56] pyranose oxidase delivered a suitable oxidase-based sensor with the hydrogen peroxide being determined again via the direct electron transfer from the carbon paste electrode to the enzyme horseradish peroxidase. In aU bi-enz5mie systems, both the enzymes were entrapped within the carbon paste. These electrodes were used as detectors in a liquid chromatography system allowing the simultaneous determination not only of several carbohydrates but also of ethanol within approximately 20 min. Ethanol production and carbohydrate consumption were monitored on-line during a fermentation of P. stipitis for 16 h (see also Section 11.2.3). 

Antiochia, R. Lavagnini, I. Magno, F. Electrocatalytic oxidation of dihydronicotinamide adenine dinucleotide with ferrocene carboxylic acid by diaphorase from Clostridium kluveri. Remarks on the kinetic approaches usually adopted. Ekctroanalysis 1999, 11, 129-133. Sanchez, P. D. Ordieres, A. J. M. Garcia, A. G. Blanco, P. T. Peroxidase ferrocene modified carbon paste electrode as an amperometric sensor for the hydrogen-peroxide assay. Ekctroanalysis 1991, 3, 281—285. 

Li et al have prepared an amperometric biosensor for hydrogen peroxide using a sol-gel immobilisation of horseradish peroxidase. HRP was entrapped in a thin silica sol-gel matrix made from tetramethoxysilane polymerised on carbon paste electrodes. The hydrogen peroxide detection was performed in the presence of hexacyanoferrate (II). Under optimised conditions, the linear range for detection of hydrogen peroxide was 2 x 10 - 2.6 x 10 M. The enzyme electrode maintained up to 65% of its activity for the period of 35 days. 

Santamaria M del Campo, Vazquez Barbado MD, Tascon Garcia ML et al. Determination of hydrogen peroxide by voltammetric techniques at carbon paste electrodes modified with transition metal phthalocyanines. Quimica Analitica 1998 17 147-152. 

Mizutani, R, S. Yabuki, and S. lijima (1995). Carbon paste electrode incorporated with cobalt(n) octaethoxyphthalocyanine for the amperometric detection of hydrogen peroxide. Electroanalysis 7(8), 706-709. 

The classic peroxidase immobilization has been extended to electrodes, e.g., determination of hydrogen peroxide based on a peroxidase/ferrocene-embedded carbon paste electrode covered with a Nafion-coated cellulose acetate membrane. The system was successfully used for glucose and urate in serum. 

Li, G., Wang, Y, and Xu, H. (2007) A hydrogen peroxide sensor prepared by electro-polymerization of pyrrole based on screen-printed carbon paste electrodes. Sensors, 7, 239- 250. 

Cai, X.-R, Kalcher, K., Koelbl, G., Neuhold, C.G., Diewald, W., and Ogorevc, B. (1995) Electrocatalytic reduction of hydrogen peroxide on a palladium-modified carbon paste electrode. Electroanalysis, 7, 340- 345. 

Schachl, K., Alemu, H., Kalcher, K, Jezkova,Svancara, I., and Vytfas, K. (1997) Flow injection determination of hydrogen peroxide using a carbon paste electrode modified with a manganese dioxide film. Anal. Lett, 30, 2655-2673. 

Schachl K, Alemu H, Kalcher K, Jezkova J, Svancara I, Vytfas K (1997) Amperometiic determination of hydrogen peroxide with a manganese dioxide-modified carbon paste electrode using flow injection analysis. Analyst 122(9) 985-989... 

Zheng X, Guo Z (2000) Potentiometric determination of hydrogen peroxide at Mn02-doped carbon paste electrode. Talanta 50 1157—1162... 

Xu GB, Dong SJ (1999) Chemiluminescent determination of luminol and hydrogen peroxide using hematin immobilized in the bulk of a carbon paste electrode. Electroanalysis 11 1180-1184... 

Compagnone D, Schweicher P, Kauffmann J-M, Guilbault GG (1998) Sub-micromolar detection of hydrogen peroxide at a peroxidise/tetramethylbenzidine solid carbon paste electrode. Anal Lett 31(7) 1107-1120... 

Iron phthalocyanin incorporated into a carbon paste electrode exhibits a catalase-like activity and has been successfully used for the electrochemical oxidation of hydrogen peroxide . 

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