In Vitro Analyte Sensor and Methods of Use

Abstract

In vitro electrochemical sensors that provide accurate and repeatable analysis of a sample of biological fluid are provided. Embodiments include sensors that include a sample chambers having overhangs extending therefrom.

1 - 41 . (canceled) 
     
     
         42 . A sensor for determining the concentration of an analyte in a sample, the sensor comprising:
 a first substrate and a second substrate;   a sample chamber positioned between the first and second substrates;   a first electrode and a second electrode positioned in the sample chamber;   wherein the second substrate extends past the first substrate at a sample receiving end of the sensor, wherein the sample chamber comprises at least two unbounded sides at the sample receiving end of the sensor.   
     
     
         43 . The sensor of  claim 42 , wherein length of the second substrate is greater than length of the first substrate. 
     
     
         44 . The sensor of  claim 42 , wherein length of the first substrate is equal to length of the second substrate. 
     
     
         45 . The sensor of  claim 42 , wherein the sample chamber comprises three unbounded sides. 
     
     
         46 . The sensor of  claim 42 , wherein about 10% to about 95% of the perimeter of the sample chamber is unbounded. 
     
     
         47 . The sensor of  claim 46 , wherein about 50% to about 95% of the perimeter of the sample chamber is unbounded. 
     
     
         48 . The sensor of  claim 42 , wherein the sample chamber has a volume of no more than about 1 microliter. 
     
     
         49 . The sensor of  claim 42 , wherein the sample chamber has a volume of no more than about 0.5 microliter. 
     
     
         50 . The sensor of  claim 42 , wherein the sample chamber has a volume of no more than about 0.1 microliter. 
     
     
         51 . The sensor of  claim 42 , wherein the sensor is a glucose sensor or a ketone body sensor. 
     
     
         52 . A sensor for determining the concentration of an analyte in a sample, the sensor comprising:
 a first substrate and a second substrate;   a sample chamber positioned between the first and second substrates;   a first electrode and a second electrode positioned in the sample chamber;   wherein the second substrate extends past the first substrate at a sample receiving end of the sensor and is configured to form a capillary chamber at a sample receiving end of the sensor when positioned in opposition to a surface, wherein the sample chamber comprises at least two unbounded sides at the sample receiving end of the sensor.   
     
     
         53 . The sensor of  claim 52 , wherein the capillary chamber has a volume that ranges from about 10 nL to about 10,000 nL. 
     
     
         54 . The sensor of  claim 53 , wherein the volume ranges from about 100 nL to about 1000 nL. 
     
     
         55 . A system for determining the concentration of an analyte in a sample, the system comprising:
 a sensor for determining the concentration of an analyte, the sensor comprising:   a first substrate and a second substrate;   a sample chamber positioned between the first and second substrates;   a first electrode and a second electrode positioned in the sample chamber;   wherein the second substrate extends past the first substrate at a sample receiving end of the sensor, wherein the sample chamber comprises at least two unbounded sides at the sample receiving end of the sensor; and   a meter.   
     
     
         56 . A method of providing a sample to a sample chamber of an analyte sensor comprising:
 contacting a sample receiving end of sensor, for determining the concentration of an analyte, with the sample, the sensor comprising:
 a first substrate and a second substrate; 
 a sample chamber positioned between the first and second substrates; 
 a first electrode and a second electrode positioned in the sample chamber; 
 wherein the second substrate extends past the first substrate at a sample receiving end of the sensor, wherein the sample chamber comprises at least two unbounded sides at the sample receiving end of the sensor. 
   
     
     
         57 . The method of  claim 56 , further comprising determining the concentration of an analyte in at least a portion of the sample in the sample chamber. 
     
     
         58 . The method of  claim 57 , wherein the concentration of the analyte is determined using about 1 microliter of sample or less. 
     
     
         59 . The method of  claim 56 , wherein the concentration of the analyte is determined using coulometry, amperometry, potentiometry, or photometry. 
     
     
         60 . The method of  claim 56 , wherein the contacting comprises first contacting the sample with the second substrate extending past the first substrate at a sample receiving end of the sensor and then contacting the first substrate and/or the sample chamber with the sample.