University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Electrode

Classification: Electrode -> ion selective -> peroxidase

Citations 5

"Flow Injection Analysis For Glucose By The Combined Use Of An Immobilized Glucose Oxidase Reactor And A Peroxidase Electrode"
Anal. Chim. Acta 1984 Volume 165, Issue 1 Pages 291-296

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Toshio Yao, Minoru Sato, Yoshiaki Kobayashi and Tamotsu Wasa

Abstract: The amperometric peroxidase electrode is constructed by cross-linking peroxidase wih bovine serum albumin with use of glutaraldehyde on a platinum sheet silanized with 3-aminopropyltriethoxysilane. Ferricyanide is generated from a 2 µL sample of Fe(CN)64- by oxidation with H2O2 released from glucose by immobilized glucose oxidase, covalently bound to silica gel, and measured. The peak current is rectilinearly related to the glucose concentration. in the range 0.05 to 10 g l-1; sample throughput can be ~100 h-1, and ascorbic acid (0.5 mM) does not interfere.
Glucose Immobilized enzyme Interferences Reactor Silica gel

"Amperometric Assays Of Total And Free Cholesterols In Serum By The Combined Use Of Immobilized Cholesterol Esterase And Cholesterol Oxidase Reactors And Peroxidase Electrode"
Anal. Biochem. 1985 Volume 149, Issue 2 Pages 387-391

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Toshio Yao, Minoru Sato, Yoshiaki Kobayashi and Tamotsu Wasa

Abstract: A flow injection system for assays of total cholesterol and free cholesterol was described. The total cholesterol assay system included an amperometric peroxidase electrode to measure hexacyanoferrate(III) converted from hydrogen peroxide, which was generated by injecting a 2 µL sample into the packed-bed reactors of immobilized cholesterol esterase and cholesterol oxidase covalently bound to silica. The free cholesterol was assayed with the same system without the cholesterol esterase reactor. The peak current was linearly related to cholesterol in the range 2-160 mg/dl and to total cholesterol in the range 3-300 mg/dl; the assay speed was about 80 samples/h for free cholesterol and 40 samples/h for total cholesterol. Reliable results were obtained in the assays of free cholesterol and total cholesterol in human sera. Both the reactors and the peroxidase electrode retained over 90% of their original activities, even after repetitive use for 4 and 2 months, respectively. Cholesterol esterase and cholesterol oxidase were separately immobilized on silica packed into columns (length 10 and 30 cm, respectively). The injection of a sample (2 µL) containing cholesterol (free and/or esterified) resulted in generation of H2O2 by the immobilized enzymes, and the H2O2 was used to generate Fe(CN)63- from Fe(CN)64- in an immobilized peroxidase electrode. The Fe(CN)63- could be measured amperometrically at low potential (-50 mV vs. silver - Ag+), so that there was little interference from other normal constituents of serum. Free cholesterol was assayed by omission of the cholesterol esterase reactor. The peak current was rectilinearly related to cholesterol concentration. in the range 2 to 160 mg dl-1 or cholesteryl palmitate concentration. in the range 3 to 300 mg dl-1. About 80 samples h-1 could be assayed for free cholesterol or 40 h-1 for total cholesterol. Within-assay coefficient of variation were <1.5%. Results agreed well with those from a chemical method. The reactors and the electrode retained >90% of their original activities after repetitive use for 4 and 2 months, respectively.
Cholesterol, free Serum Human Interferences Immobilized enzyme Silica

"Determination Of Ethanol In Serums By The Use Of Immobilized Enzymes In A Flow Injection Amperometry System"
Bunseki Kagaku 1985 Volume 34, Issue 8 Pages 513-515

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Yao, T.;Matsumoto, Y.;Wasa, T.

Abstract: Serum was applied to a column of immobilized alcohol oxidase with a carrier solution (1.4 mL min-1) of 0.1 M phosphate buffer (pH 8) containing 1 mM K4Fe(CN)6. The H2O2 produced converted K4Fe(CN)6 into K3Fe(CN)6, which was measured with a peroxidase electrode at 0.0 V vs. silver - AgCl. The calibration graph was rectilinear for 0.02 to 10 mM and the coefficient of variation was 1 to 2%.
Ethanol Blood Serum Immobilized enzyme

"Simultaneous Assay Of Glucose And Total Cholesterol In Blood Serum Using A Flow Injection System With Immobilized Enzymes"
J. Flow Injection Anal. 1988 Volume 5, Issue 1 Pages 5-13

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Toshio YAO, Reina AKASAKA, and Tamotsu WASA

Abstract: A flow injection system is described (with diagram) incorporating two immobilized enzyme reactors in parallel. Sample solution (5 µL) is injected into the carrier stream (3 mL min-1) of 0.1 M phosphate buffer (pH 7.5) containing 2.0% of Triton X-100 and 1.0 mM K4Fe(CN)6. The stream is split, and one stream is passed through an immobilized cholesterol oxidase - cholesterol esterase reactor and the second stream is passed through an immobilized glucose oxidase reactor and a delay coil before convergence with the first stream; amperometric detection is carried out with use of a flow-through peroxidase electrode at -50 mV vs. Ag - AgCl. Calibration graphs (peak current vs. concentration.) were rectilinear from 20 to 200 mg L-1 of total cholesterol(I) and from 40 to 4000 mg L-1 of glucose(II). Down to 0.3 mg L-1 of I and 0.5 mg L-1 of II could be detected. The coefficient of variation (n = 10) was 1.8%.
Cholesterol, total Glucose Blood Serum Immobilized enzyme Triton X Surfactant

"Flow Injection Analysis For Uric Acid By The Combined Use Of An Immobilized Uricase Reactor And A Peroxidase Electrode"
Nippon Kagaku Kaishi 1985 Volume 1985, Issue 2 Pages 189-192

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Yao, T.;Sato, M.;Wasa, T.

Abstract: The sample (2 µL) is injected into a reactor containing immobilized urate oxidase. The carrier stream comprises 0.1 M borate buffer (pH 9.0) containing 0.2 M NaCl and 1 mM K4Fe(CN)6 and pumped at 1.5 mL min-1. The H2O2 generated in the reactor forms K3Fe(CN)6 in the presence of a peroxidase electrode. This electrode operates at only ~-50 mV vs. silver - Ag+, so that little interference is caused by other constituents of serum or urine. The peak current is rectilinearly related to uric acid concentration. in the range 0.2 to 8 mg dl-1. The peak width is ~30 s, so that 90 to 120 samples can be analyzed in 1 h with a coefficient of variation of 1 to 2%. Results show excellent agreement with those by the urate oxidase - u.v. method.
Uric acid Blood Serum Urine Wine Interferences Immobilized enzyme Method comparison Peak width