Devices for analyte concentration determination and methods of manufacturing and using the same
View Patent ↗Test strips for determining the concentration of at least one analyte, e.g., glucose, in a physiological sample and methods for their manufacture and use and are provided. The subject test strips include a transfer element for facilitating the transfer of sample to a reaction area of the test strip. In certain embodiments, the transfer element, typically porous, has a first area and a second area, and in certain embodiments the two areas have different thicknesses. In other embodiments, the transfer element is non-porous and is configured to transfer sample by wicking it between the transfer element and the reaction area of the test strip. In the subject methods, the transport element facilitates transfers of a sample to a reaction area of the test strip. The subject test strips and methods find use in a variety of different applications, particularly in the determination of glucose concentrations.
1. A test strip for determining the concentration of at least one analyte in a physiological sample, said test strip comprising;
a support;
a membrane comprising at least one testing reagent for determining the concentration of at least one analyte in a physiological sample, said membrane having a first surface attached to said support and a second surface opposite said first surface; and
a fluid transfer element for transferring said sample to said membrane, said fluid transfer element comprising at least a first area and a second area, wherein the thickness of said first area is greater than the thickness of said second area and said second area directly overlies said second surface of said membrane.
2. The test strip according to claim 1 , wherein the ratio of the thickness of the first area to the second area ranges from about 1.1 to 1.9.
3. The test strip according to claim 1 , wherein said ratio ranges from about 1.1 to 1.7.
4. The test strip according to claim 1 , wherein said thickness of said second area ranges from about 0.015 inches to 0.022 inches.
5. The test strip according to claim 1 , wherein said fluid transport element comprises a porous material.
6. The test strip according to claim 1 , wherein said fluid transport element is selected from the group consisting of cotton, cellulose, polyester, polyamide and polyethylene.
7. The test strip according to claim 1 , wherein said fluid transport element comprises a surfactant.
8. The test strip according to claim 1 , wherein said second area is substantially rectangular.
9. The test strip according to claim 8 , wherein said second area has a length in the range from about 0.10 inches to 0.40 inches and a width in the range from about 0.15 inches to 0.60 inches.
10. The test strip according to claim 1 , wherein said second area is substantially circular.
11. The test strip according to claim 9 , wherein said second area has a diameter in the range from about 0.01 inches to 0.21 inches.
12. The test strip according to claim 1 , wherein said second area is capable of being saturated with a sample volume from about 1 to 7 microliters.
13. The test strip according to claim 1 , wherein said second area is capable of transferring a sample volume from about 0.1 to 5.0 microliters to a reaction area of said test strip.
14. The test strip according to claim 1 , wherein said second area further comprises at least one lateral extension.
15. The test strip according to claim 14 , wherein said at least one lateral extension comprises a lumen therethrough.
16. The test strip according to claim 14 , wherein said support layer comprises at least one notch therein, and said at least one lateral extension is configured to extend beyond said at least one notch.
17. A kit for determining the concentration of at least one analyte in a physiological sample, said kit comprising:
(a) at least one test strip according to claim 1 ; and
(b) a substrate comprising instruction for using said at least one test strip to determine said concentration of at least one analyte in a physiological sample.