The Yellow Springs Instrument Company

Ysi, Inc.

Scnte, LLC

Jay M Johnson

Robert B Spokane

Bill L Riehl

Jim R Riehl

Lee R Riehl

Bonnie D Riehl

Jeffrey L Huntington

A process for producing a nanostructured carbon material including the steps of providing a metal or metalloid carbide substrate and reacting the carbide substrate with a reactive gas to form the nanostructured carbon material, the reactive gas and the carbide substrate being added during the reacting step.

Process for the production of nanostructured carbon materials

Laminated membrane structure for polarographic measurement and methods

Methods for forming thin layer barrier layer films for use in enzyme containing laminated membranes and membranes formed thereby are disclosed. The barrier layers exhibit improved acetaminophen rejection and comprise a cellulose acetate/cellulose acetate butyrate blend. The thin layer barrier membranes are formed from a plural solvent containing solution and are cured at a critical temperature of about 102.degree.-114.degree. F., most preferably at about 106.degree. F.-114.degree. F. while traveling through a circulating hot air oven. Alternatively, the membranes can be cured at room temperature or in a stagnant oven at temperatures of from room temperature to about 175.degree. C. (350.degree. F.) for a period of from about 10 minutes to 1 hour.

Processes for preparing barrier layer films for use in enzyme electrodes

Improved Newman type enzyme containing laminated membranes are disclosed for use in conjunction with polarographic cells to measure analyte concentration in solutions. The laminated membranes comprise a semipermeable outer, support layer including super large pores of greater than about 200 .ANG. in diameter. The outer layer preferably comprises pore sizes of about 380-750 .ANG. in diameter and has a percentage porosity of about 0.005-0.2%.

Support layer for enzyme electrode laminated membranes

Improved methods and compositions are provided to inhibit interference from formaldehyde in polarographic analytic methods. In the enzymatic oxidation of methanol to hydrogen peroxide and formaldehyde, formaldehyde serves as an interfering agent in systems where the oxygen consumed or the hydrogen peroxide produced is polarographically measured. To inhibit this interference, an amine-containing formaldehyde scavenger is added to the test system. Preferably, the scavenger comprises a polyalkyleneimine such as polyethyleneimine having a molecular weight of between about 200-1,000,000 amu. The invention is particularly well-suited for use in polarographic analytical apparatus wherein laminated membrane type enzyme electrodes are used to perform amperometric measurement with alcohol oxidase enzyme used as the oxidoreductase enzyme. Determination of methanol concentration in liquid samples can be used to assess the amount of L-Asp-L-Phe-methyl ester (aspartame-TM) present in diet soft drink samples that have been hydrolyzed with the enzyme Bovine alpha-chymotrypsin to yield L-Asp-L-phe and methanol.

Methods for reducing level of interferants in biosensor systems and

Combined golf ball marker and holder

A method for control of relative enzyme activity for analytical purposes. The activity of a multisubstrate enzyme may be controlled as a function of the electrical potential applied to the enzyme. The enzyme is preferrably incorporated into a thin layer electrochemical cell laminate having exterior membrane layers and an interior enzyme layer. A control electrode located within the enzyme layer applies an electrical potential to the enzyme. An intermediate electron transfer agent may be used to transfer electrons to and from the enzyme and the control electrode.

Method for quantitatively determining a particular substrate catalyzed

The relative specificity of the enzyme galactose oxidase for various substrates is controlled as a function of the electrical potential applied to the enzyme. The enzyme is incorporated into a thin layer electrochemical cell laminate having exterior membrane layers and an interior enzyme layer. An electrode located within the enzyme layer applies varying electrical potentials to the enzyme. An intermediate electron transfer agent may be used to transfer electrons to and from the enzyme and electrode.

Substrate specific galactose oxidase enzyme electrodes

Galactose oxidase enzyme can effectively be used for the determination of a number of different substances if activated and stabilized in accordance with the present invention. Activation is accomplished with a redox agent such as ferricyanide. Stabilization of the activated galactose oxidase is accomplished by addition of cupric ion. Upon stabilization, activated, immobilized galactose oxidase enzymes may be stored and reused for at least 25 days.

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Dayton, OH, United States of America

Jay M Johnson