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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Seed

Classification: Plant -> pea -> seed

Citations 1

"Improvement Of The Selectivity Of An Flow Injection Analysis Amperometric Biosensor System For Glucose"
Biosens. Bioelectron. 1993 Volume 8, Issue 5 Pages 239-247
K. B. Male and J. H. T. Luong*

Abstract: In the cited flow injection analysis system, samples (75 µL) were injected into a stream (31 ml/h) of 1 mM acetate buffer of pH 4-7.2 and carried to a column (12 cm x 2.54 mm i.d.) of acetate AG 1-X8 anion-exchange resin (200-400 mesh) to remove interfering substances including uric acid and ascorbic acid. The stream then merged with a stream (31 ml/h) of 100 mM acetate buffer of pH 5.5 containing 1 M NaCl and passed through an enzyme reactor column (6 cm x 2.54 mm i.d.) prepared by immobilizing glucose oxidase onto aminopropyl glass beads using glutaraldehyde (details given) and packing the beads into Tygon tubing. H2O2 was determined using an amperometric flow cell with an Immunodyne membrane (3 µm) and a Pt electrode held at +700 mV vs. Ag/AgCl. The optimum pH for ascorbic acid and uric acid removal were 4 and >6, respectively; the anion-exchange column was less efficient at removing paracetamol. The calibration graph was linear for up to 1 mM glucose and the detection limit was 10 µM. Reproducibility was good and the enzyme reactor was stable for >2000 analyzes; sample throughput was 17/h. The method was applied to urine, plasma, fruit juices and pea and bean seed extracts (details given). A flow injection analysis (flow injection analysis) biosensor system has been developed for the determination of glucose from urine, blood plasma and foodstuffs. Glucose oxidase was immobilized onto porous aminopropyl glass beads via glutaraldehyde activation to form an enzyme column. The hydrogen peroxide released from the conversion of glucose to gluconic acid was monitored by a platinum electrode vs. silver/silver chloride poised at +700 mV. As a novel aspect to the improvement of the selectivity of the biosensor system, an anion exchange column was placed upstream to remove uric acid, ascorbic acid or acetaminophen, three major electroactive interfering substances which usually occur in urine and blood plasma. Among several resins tested, the effective adsorption of uric and ascorbic acids could be accomplished using an acetate anion exchanger, and the selectivity coefficient was pH dependent. The binding of acetaminophen to the resin was much less efficient and, in all cases, the selectivity coefficient was independent of the operating temperature up to 37°C. When applied to real samples, the data obtained by the biosensor system compared well with those of the standard hexokinase assay. The immobilized glucose oxidase could be reused for at least 2000 repeated analyzes without loss of its original activity.
Glucose Amperometry HPIC Electrode Sensor Biotechnology Selectivity Immobilized enzyme Interferences Glass beads