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A M Yacynych

Publications and source records attributed to A M Yacynych.

5 recordsLinked to original sources
PubMed1998

Determination of galactose and galactocerebroside using a galactose oxidase column and electrochemical detector.

A method has been developed to measure galactose and galactocerebroside using galactose oxidase immobilized on a solid resin. Galactose oxidase converts galactose and galactocerebroside to their corresponding aldehydes and hydrogen peroxide, the latter being electroactive and measurable by electrochemical detection using DC amperometric detection. The minimal detection limits of galactose and galactocerebroside were 1 and 2 microM, respectively. The linear response to galactose and galactocerebroside was to at least 300 microM. About 100 samples can be measured per hour using flow injection analysis. The activity of sulfatidase (cerebroside-3-sulfate-3-sulfohydrolase), which converts sulfatide (sulfogalactocerebroside) to galactocerebroside, was measured, and its inhibition by O-phospho-L-tyrosine was determined.

Biosensing Techniques↗
PubMed1995

Galactose biosensors using composite polymers to prevent interferences.

A biosensor using a composite polymer to prevent interferences was used in a flow injection analysis system for the detection of galactose in human plasma. The biosensor consisted of galactose oxidase immobilized on a platinized carbon electrode that had been modified with a composite polymer. The composite polymer showed improved selectivity to hydrogen peroxide compared with either of its individual polymeric components, Nafion and a copolymer of diaminobenzene and resorcinol. The composite polymer minimized the effect of possible interference from urate, ascorbate, and acetaminophen. This analytical system had a minimum detection limit of 50 microM, linearity to 6 mM, a storage stability of greater than 30 days, and a high sample throughput (approx. 120 samples/h).

Biosensing Techniques↗
PubMed1994

Direct sensing platinum ultramicrobiosensors for glucose.

Miniaturized glucose biosensors were constructed from disk-shaped ultramicroelectrodes (UMEs) (diameter = 10 microns and 25 microns), cylindrical UMEs (diameter = 25 microns), and platinum black modified UMEs. Glucose oxidase (E.C.1.1.3.4) was immobilized by glutaraldehyde cross-linking. All ultramicrobiosensors (UMBs) had response times (100% response) of less than 1 min, and had linear response over the human clinical range for glucose (3-7 mM). Response to glucose was linear over a greater concentration range at cylindrical UMBs, compared to similarly prepared disk-shaped UMBs, typically from 3-20 mM glucose. Thin, electrochemically polymerized films were used to prevent signals due to interfering species. A variety of different films, and electropolymerization conditions were examined. Poly(1,3-diaminobenzene) (1,3-DAB) was found to be the most effective at preventing signals due to interferents. Poly(1,3-DAB) was used to protect the biosensor from fouling. A 25 microns biosensor, with poly(1,3-DAB), was used for the direct measurement of glucose in complex samples.

Animals↗