Analyte Sensors and Methods of Use

Abstract

Analyte sensors for determining the concentration of an analyte in a sample. The sensors have a sample chamber having an inlet with a projection extending from an edge of the sensor for facilitating flow of sample into the sample chamber.

1 .- 24 . (canceled) 
     
     
         25 . A sensor for determining the concentration of an analyte in a sample, the sensor comprising:
 a first substrate and a second substrate;   a spacer between the first substrate and the second substrate;   a sample chamber having only two inlets, a first inlet and a second inlet, the first inlet and the second inlet defined by the first substrate, second substrate, and spacer;   a first projection extending from a first edge of the sensor at the first inlet, wherein the first projection is defined by the first substrate, and wherein a width of the first projection at the first edge of the sensor is less than a width of the first inlet; and   a second projection extending from the first edge of the sensor at the first inlet, wherein the second projection is defined by the second substrate, and wherein a width of the second projection at the first edge of the sensor is less than a width of the first inlet.   
     
     
         26 . The sensor of  claim 25 , wherein the distal end of the sensor comprises:
 a portion of a first side edge of the sensor;   a portion of a second side edge of the sensor; and   an end edge of the sensor, the end edge extending from the portion of the first side edge to the portion of the second side edge.   
     
     
         27 . The sensor of  claim 26 , wherein the portion of the first side edge and the portion of the second side edge are linear. 
     
     
         28 . The sensor of  claim 26 , wherein the portion of the first side edge and the portion of the second side edge are curved. 
     
     
         29 . The sensor of  claim 26 , wherein the portion of the first side edge and the portion of the second side edge are tapered. 
     
     
         30 . The sensor of  claim 26 , wherein one or more sections of the portion of the first side edge and the portion of the second side edge are tapered. 
     
     
         31 . The sensor of  claim 26 , wherein one or more sections of the portion of the first side edge and the portion of the second side edge are parallel. 
     
     
         32 . The sensor of  claim 26 , wherein the portion of the first side edge and the portion of the second side edge are non-parallel and curved. 
     
     
         33 . The sensor of  claim 26 , wherein the portion of the first side edge and the portion of the second side edge are linear with a curved transition region. 
     
     
         34 . The sensor of  claim 33 , wherein the portion of the first side edge and the portion of the second side edge are linearly tapered. 
     
     
         35 . The sensor of  claim 25 , wherein the width of the first projection is approximately 80% of the width of the first inlet and the width of the second projection is approximately 80% of the width of the first inlet. 
     
     
         36 . The sensor of  claim 25 , the width of the first projection is approximately 50% of the width of the first inlet and the width of the second projection is approximately 50% of the width of the first inlet. 
     
     
         37 . The sensor of  claim 25 , wherein the first and second projections have a height of at least 0.2 mm. 
     
     
         38 . The sensor of  claim 25 , wherein the sample chamber has a volume of one microliter or less. 
     
     
         39 . The sensor of  claim 25 , wherein the analyte is glucose and the sample chamber comprises a glucose-responsive enzyme. 
     
     
         40 . The sensor of  claim 25 , wherein the analyte is ketone and the sample chamber comprises a ketone-responsive enzyme. 
     
     
         41 . The sensor of  claim 25 , comprising a third projection extending from a second edge of the sensor at the second inlet, wherein the third projection is defined by the first substrate, and wherein a width of the third projection is less than a width of the second inlet. 
     
     
         42 . The sensor of  claim 41 , comprising a fourth projection extending from the second edge of the sensor at the second inlet, wherein the fourth projection is defined by the second substrate, and wherein a width of the fourth projection is less than a width of the second inlet. 
     
     
         43 . The sensor of  claim 25 , wherein the spacer comprises a first portion and a second portion, wherein the first portion is positioned at the distal end of the sensor and the first portion is smaller than the second portion.