Devices for analyte concentration determination and methods of manufacturing and using the same

Abstract

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 fluid transfer element for transferring said sample to a reaction area of said test strip, said fluid transfer element comprising at least a first area and a second area, wherein the thickness of said first area differs from the thickness of said second area.  
     
     
         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 test strip further comprises a support layer, wherein said support layer comprises at least one notch therein, and said at least one sample application feature is configured to extend beyond said at least one notch.  
     
     
         17 . A test strip for determining the concentration of at least one analyte in a physiological sample, said test strip comprising a fluid transfer element for transferring said sample to a reaction area of said test strip, said fluid transfer element comprising at least a first area and a second area, wherein said second section is configured to receive sample and said first section is configured to receive excess sample.  
     
     
         18 . The test strip according to  claim 17 , wherein said fluid transport element comprises a porous material.  
     
     
         19 . The test strip according to  claim 17 , wherein said fluid transport element is selected from the group consisting of cotton, cellulose, polyester, polyamide and polyethylene.  
     
     
         20 . The test strip according to  claim 17 , wherein said fluid transport element comprises a surfactant.  
     
     
         21 . The test strip according to  claim 17 , wherein said second area is substantially rectangular.  
     
     
         22 . The test strip according to  claim 21 , 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.  
     
     
         23 . The test strip according to  claim 17 , wherein said second area is substantially circular.  
     
     
         24 . The test strip according to  claim 23 , wherein said second area has a diameter in the range from about 0.01 inches to 0.21 inches.  
     
     
         25 . The test strip according to  claim 17 , wherein said second area is capable of being saturated with a sample volume from about 1 to 7 microliters.  
     
     
         26 . The test strip according to  claim 17 , 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.  
     
     
         27 . The test strip according to  claim 17 , wherein said second area further comprises at least one lateral extension.  
     
     
         28 . The test strip according to  claim 27 , wherein said at least one lateral extension comprises a lumen therethrough.  
     
     
         29 . The test strip according to  claim 27 , wherein said test strip further comprises a support layer, wherein said support layer comprises at least one notch therein, and said at least one sample application feature is configured to extend beyond said at least one notch.  
     
     
         30 . A test strip for determining the concentration of at least one analyte in a physiological sample, said test strip comprising a non-porous transport element for transferring said sample to a reaction area of said test strip.  
     
     
         31 . The test strip according to  claim 30 , wherein said non-porous transfer element is configured to transfer said sample between said non-porous transfer element and said reaction area.  
     
     
         32 . The test strip according to  claim 30 , wherein said non-porous transfer element comprises at least a first area and a second area.  
     
     
         33 . The test strip according to  claim 32 , wherein said second area is substantially rectangular.  
     
     
         34 . The test strip according to  claim 33 , wherein said second area has a length in the range from about 0.14 inches to 0.4 inches and a width in the range from about 0.15 inches to 0.6 inches.  
     
     
         35 . The test strip according to  claim 32 , wherein said second area is substantially circular.  
     
     
         36 . The test strip according to  claim 35 , wherein said second area has a diameter in the range from about 0.1 inches to 5.0 inches.  
     
     
         37 . The test strip according to  claim 30 , further comprising at least one lateral extension.  
     
     
         38 . The test strip according to  claim 37 , wherein said test strip further comprises a support layer, wherein said support layer comprises at least one notch therein, and said at least one sample application feature is configured to extend beyond said at least one notch.  
     
     
         39 . The test strip according to  claim 30 , wherein said non-porous transport element comprises a sample directing means.  
     
     
         40 . The test strip according to  claim 30 , further comprising a sample confinement element.  
     
     
         41 . The test strip according to  claim 30 , further comprising a support layer, wherein said support layer comprises notches therein.  
     
     
         42 . The test strip according to  claim 30 , further comprising a spacer layer configured between said non-porous transport element and said membrane.  
     
     
         43 . The test strip according to  claim 30 , further comprising at least one sample directing means.  
     
     
         44 . A method for making the test strip according to  claim 1 , said method comprising the steps of: 
 (a) providing a compression mold assembly comprising a protrusion configured to mold a second area of said transport element of  claim 1;     (b) providing precursor material;    (c) inserting said precursor material within said mold assembly; and    (c) applying pressure to said precursor material to provide a resulting transport element of  claim 1 .    
     
     
         45 . The method according to  claim 44 , wherein said pressure is applied to create a distance between a first portion and a second portion of said mold assembly ranging from about 0.010 inches to 0.020 inches.  
     
     
         46 . The method according to  claim 44 , further comprising the step of applying heat.  
     
     
         47 . The method according to  claim 44 , wherein said step of providing comprises providing a porous precursor material.  
     
     
         48 . The method according to  claim 44 , wherein said step of providing comprises providing a precursor material that is selected from the group consisting of cotton, cellulose, polyester, polyamide and polyethylene.  
     
     
         49 . A method for making a transport element of a test strip, said method comprising: 
 (a) providing a compression mold assembly configured to make a transport element having at least a first area and a second area, wherein the thickness of said first area and said second area differ;    (b) inserting a precursor material within said mold assembly; and    (c) applying pressure to said precursor material to provide said transport element having at least a first area and a second area, wherein the thickness of said first area and said second area differ.    
     
     
         50 . A method for determining the concentration of at least one analyte in a physiological sample, said method comprising applying sample to a test strip comprised of a fluid transport element, wherein said fluid transport element is comprised of at least a first area and a second area having different thicknesses.  
     
     
         51 . The method according to  claim 50 , wherein said thickness of said second area is less than the thickness of said first area, and said step of applying comprises applying sample to said second area.  
     
     
         52 . The method according to  claim 50 , wherein said test strip further comprises a reaction area, and said step of applying further comprises applying a sample volume from about 1 to 7 microliters to said second area, whereby said second area transfers a volume from about 0.1 to 5 microliters of said sample to said reaction area.  
     
     
         53 . The method according to  claim 50 , wherein said test strip further comprises at least one lateral extension and said sample is initially applied to said at least one lateral extension.  
     
     
         54 . The method according to  claim 53 , wherein said at least one lateral extension comprises a lumen, and said sample is applied through said lumen.  
     
     
         55 . A method for determining the concentration of at least one analyte in a physiological sample, said method comprising applying sample to one or more sides of a test strip.  
     
     
         56 . The method according to  claim 55 , wherein said step of applying comprises applying from about 1 to 8 microliters of said sample to said one or more sides.  
     
     
         57 . The method according to  claim 55 , wherein said test strip comprises at least one lateral extension and said sample is initially applied to said at least one sample application feature.  
     
     
         58 . The method according to  claim 57 , wherein said at least one lateral extension comprises a lumen, and said sample is applied through said lumen.  
     
     
         59 . The method according to  claim 55 , wherein said test strip comprises a transport element and a reaction area, and said sample is wicked between said transport element and said reaction area.  
     
     
         60 . The method according to  claim 55 , wherein said test strip comprises a sample confinement element, and said step of applying further comprises substantially confining said sample to an area below said sample confinement element.  
     
     
         61 . The method according to  claim 55 , further comprising directing the flow of said sample.  
     
     
         62 . A kit for determining the concentration of at least one analyte in a physiological sample, said kit comprising: 
 (a) at least one test strip selected from the group consisting of a test strip according to  claim 1  and a test strip according to  claim 17;  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.    
     
     
         63 . 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 30;  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.