Matrix stability compositions, test elements, test systems and methods of use thereof
First Claim
1. A test element for determining a presence or a concentration of an analyte in a sample fluid, comprising:
- at least one working electrode and at least one counter electrode disposed upon a substrate; and
a dry-film reagent matrix extending between the at least one working electrode and the at least one counter electrode and configured for an electrode reaction, wherein the dry-film reagent matrix comprises a deliquescent material and one or more active ingredients effective for facilitating a desired electrochemical reaction, wherein the deliquescent material is sodium chloride, magnesium sulfate, or a combination thereof, wherein the deliquescent material is present in an amount effective to preemptively absorb water from the atmosphere when the relative humidity exceeds a predetermined level, and wherein the deliquescent material has a deliquescence point between about 50% relative humidity and about 80% relative humidity.
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Accused Products
Abstract
Reagent matrices and methods are disclosed for improving the stability of test elements with respect to degradation by humidity in the air. The reagent matrices and methods are based upon using an effective amount of a deliquescent material to decrease the sorption of water from the air by other components of a reagent matrix. When the test element is a glucose-specific test strip, and the reagent matrix can include a glucose dehydrogenase enzyme and/or a flavin adenine dinucleotide cofactor, a nitrosoaniline mediator, and a film former, where the deliquescent material may include a salt such as sodium chloride in an amount effective to absorb water from the atmosphere at a rate that is faster than the rate at which the other components of the reagent matrix absorb water from the atmosphere.
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Citations
15 Claims
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1. A test element for determining a presence or a concentration of an analyte in a sample fluid, comprising:
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at least one working electrode and at least one counter electrode disposed upon a substrate; and a dry-film reagent matrix extending between the at least one working electrode and the at least one counter electrode and configured for an electrode reaction, wherein the dry-film reagent matrix comprises a deliquescent material and one or more active ingredients effective for facilitating a desired electrochemical reaction, wherein the deliquescent material is sodium chloride, magnesium sulfate, or a combination thereof, wherein the deliquescent material is present in an amount effective to preemptively absorb water from the atmosphere when the relative humidity exceeds a predetermined level, and wherein the deliquescent material has a deliquescence point between about 50% relative humidity and about 80% relative humidity. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of improving stability of a test element with respect to degradation of reagent components by humidity in air, the method comprising the step of:
providing a test element comprising at least one working electrode and at least one counter electrode disposed on a substrate, and a dry-film reagent matrix extending between the at least one working electrode and the at least one counter electrode, wherein the dry-film reagent matrix comprises a deliquescent material in an amount effective to decrease the sorption of water from the air by other reagent components of the dry-film reagent matrix, and wherein the deliquescent material is sodium chloride, magnesium sulfate, or a combination thereof. - View Dependent Claims (14, 15)
Specification