Biosensor desiccant system having enhanced measurement performance

• US 9,664,638 B2
• Filed: 12/03/2015
• Issued: 05/30/2017
• Est. Priority Date: 01/22/2010
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Inventors: Chu, Amy H., Warchal-Windham, Mary Ellen
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US14/958,456
• Publication Number:
  US 20160084790A1
• Time in Patent Office: 544 Days
• CPC Class Codes: B65B 55/00 Preserving, protecting or purifying packages or package contents in association with packaging by packaging under special atmospheric or gaseous conditions B65B31/00; devices for placing protecting sheets, plugs, or wads over contents B65B61/22
• CPC Class Codes: B65D 81/266 for absorbing gases, e.g. oxygen absorbers or desiccants B65D51/244, B65D51/30 take precedence
• CPC Class Codes: C12Q 1/005 involving specific analytes or enzymes including groups of enzymes, e.g. oxydases; C12Q1/004 takes precedence
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: G01N 33/48778 Containers specially adapted therefor, e.g. for dry storage

Abstract

A biosensor system for determining the concentration of an analyte in a sample includes a plurality of test sensors, and includes a container including a desiccant and the plurality of test sensors, sealed in the container. When the container is stored for two weeks at a temperature of 50° C., and each test sensor is subsequently removed from the container, connected through the at least two conductors to a measurement device and then contacted with one of a plurality of samples including an analyte, where the plurality of samples has analyte concentrations that span the range of 50 mg/dL-600 mg/dL, and the analyte concentration in each sample is determined by the test sensor and the measuring device, the bias of each determined analyte concentration may be within ±10 mg/dL or ±10%, and the coefficient of variation of the determined analyte concentrations may be at most 2.5%.

Claims

1. A method for determining a concentration of an analyte in a sample using a biosensor system, the biosensor system including a container comprising a desiccant blend including molecular sieve and silica gel desiccants and a plurality of test sensors, each of the plurality of test sensor including a reagent composition, the container including a predetermined amount of the desiccant blend to provide a predetermined moisture level in the container, the method comprising:

removing one of the plurality of test sensors from the container;

contacting the removed test sensor with one of a plurality of samples including an analyte, each of the plurality of samples having an analyte concentration ranging from about 50 mg/dL to about 600 mg/dL; and

using a measuring device to measure the analyte concentration in the one of the plurality of samples,

wherein the biosensor system is configured to result in a bias of each measured analyte concentration compared with a reference value being within ±

10 mg/dL for samples having an analyte concentration less than 100 mg/dL and within ±

10% for samples having an analyte concentration of at least 100 mg/dL after storage in the container for about two weeks at a temperature about 50°

C.

2. The method of claim 1, wherein the desiccant blend adsorbs at most 10% of its weight in water when in contact with an environment of about 10%-20% relative humidity at about 40°

C.

3. The method of claim 1, wherein the biosensor system comprises at most 10 mg of the silica gel per test sensor.

4. The method of claim 1, wherein the plurality of test sensors is at least 50 test sensors.

5. The method of claim 1, wherein the reagent composition of each of the plurality of test sensors includes a redox enzyme, the redox enzyme retaining at least 75% of an initial activity after said storing.

6. The method of claim 1, wherein the coefficient of variation of the determined analyte concentrations of the plurality of samples is at most 2.5%.

7. The method of claim 1, wherein the container includes about 7.5 to about 30 mg per test sensor of the desiccant blend.

8. The method of claim 1, wherein the desiccant blend includes about 22.5 mg per test sensor of molecular sieve desiccant.

9. The method of claim 1, wherein each of the plurality of test sensors further includes at least two conductors, wherein one of the conductors is a working electrode.

10. The method of claim 9, further comprising connecting the removed test sensor to the measurement device via the at least two conductors.

11. A method for determining a concentration of an analyte in a sample using a biosensor system, the biosensor system including a container comprising a desiccant blend including molecular sieve and silica gel desiccants and a plurality of test sensors, each test sensor including a reagent composition having a redox enzyme, the method comprising:

removing one of the plurality of test sensors from the container,

contacting the removed test sensor a sample including an analyte; and

using a measuring device to measure the analyte concentration in the one of the plurality of samples,

wherein, after storage in the container for about two weeks at a temperature about 50°

C., the biosensor system is configured such that the reagent composition of each removed test sensor has at least 75% of an initial activity of the redox enzyme.

12. The method of claim 11, wherein the desiccant blend adsorbs at most 10% of its weight in water when in contact with an environment of about 10%-20% relative humidity at about 40°

C.

13. The method of claim 11, wherein the biosensor system comprises at most 10 mg of the silica gel per test sensor.

14. The method of claim 11, wherein the plurality of test sensors is at least 50 test sensors.

15. The method of claim 11, wherein the sample is one of a plurality of samples, each of the plurality of samples having an analyte concentration ranging from about 50 mg/dL to about 600 mg/dL, the bias of each measured analyte concentration being within ±

10 mg/dL for samples having an analyte concentration less than 100 mg/dL and within ±

10% for samples having an analyte concentration of at least 100 mg/dL.

16. The method of claim 11, wherein the coefficient of variation of the determined analyte concentrations of the plurality of samples is at most 2.5%.

17. The method of claim 11, wherein the container includes about 7.5 to about 30 mg of the desiccant blend.

18. The method of claim 11, wherein the desiccant blend includes about 22.5 mg per test sensor of molecular sieve desiccant.

19. The method of claim 11, wherein each of the plurality of test sensors further includes at least two conductors, wherein one of the conductors is a working electrode.

20. The method of claim 19, further comprising connecting the removed test sensor to the measurement device via the at least two conductors.