Method of Determining An Analyte Concentration in a Sample

Abstract

A reagent composition for a biosensor sensor strip is disclosed that provides for rapid rehydration after drying. The composition includes porous particles and is preferably formed as a colloidal suspension. The dried reagent composition including porous particles may provide analytically useful output from the sensor strip in a shorter time period than observed from dried reagent compositions using solid particles. The output signal from the porous particle compositions may be correlated to the analyte concentration of a sample within about two seconds. In this manner, an accurate concentration determination of an analyte concentration in a sample may be obtained in less time than from sensor strips including conventional compositions. The reagent composition including the porous particles also may allow for the redox reaction between the reagents and the analyte to reach a maximum kinetic performance in a shorter time period than observed from conventional sensor strips.

1 - 34 . (canceled) 
     
     
         35 . A biosensor system for determining the concentration of an analyte in a sample, the biosensor system comprising:
 a sensor strip including a reservoir for receiving the sample, a working electrode, a counter electrode, a reagent composition comprising an enzyme, an electron transfer mediator and porous particles with a plurality of pores having an average diameter from 0.05 micrometer to 10 micrometer and a void volume of at least 20% (v/v); and   a measurement device comprising a sensor interface, signal generator, and a processor, the signal generator providing an electrical input signal to the sensor interface, the processor being adapted to (i) direct the signal generator to provide the electrical input signal to the sensor interface, (ii) receive an output signal from the sensor interface, and (iii) measure the at least one output signal to obtain a current value from an excitation wherein the initial current is greater than those that follow in the decay and within less than 3 seconds of introducing the sample to the sensor strip.   
     
     
         36 . The biosensor system of  claim 35 , wherein the process is adapted to measure the at least one output signal current value within about 1.7 to about 2.7 seconds of introducing the sample to the sensor strip. 
     
     
         37 . The biosensor system of  claim 35 , wherein the analyte comprises glucose and wherein the sample comprises whole blood. 
     
     
         38 . The biosensor system of  claim 35 , wherein the at least one output signal current value is at least two output signal current values. 
     
     
         39 . The biosensor system of  claim 35 , wherein the electrical input signal includes at least one pulse interval including an excitation and a relaxation. 
     
     
         40 . The biosensor system of  claim 35 , wherein the reagent composition further comprises at least one polymeric material. 
     
     
         41 . The biosensor system of  claim 35 , wherein the porous particles have an average diameter from 0.1 to 5 micrometers (μm). 
     
     
         42 . The biosensor system of  claim 35 , wherein the porous particles have a void volume of at least 40% (v/v). 
     
     
         43 . The biosensor system of  claim 35 , wherein the plurality of pores is sized to exclude the enzyme. 
     
     
         44 . The biosensor system of  claim 35 , wherein the plurality of pores is less than about  5  nanometers. 
     
     
         45 . The biosensor system of  claim 35 , wherein the porous particles comprise silica or zeolite. 
     
     
         46 . The biosensor system of  claim 35 , wherein the reagent composition includes from about 0.5 to about 10% (w/w) of the mediator. 
     
     
         47 . The biosensor system of  claim 35 , wherein the enzyme is glucose dehydrogenase. 
     
     
         48 . The biosensor system of  claim 35 , wherein the enzyme is glucose oxidase. 
     
     
         49 . A biosensor system for determining the concentration of an glucose in a sample, the biosensor system comprising:
 a sensor strip including a reservoir for receiving the sample, a working electrode, a counter electrode, a reagent composition comprising an enzyme, an electron transfer mediator, at least one polymeric material, and porous particles with a plurality of pores having an average diameter from 0.05 micrometer to 10 micrometer and a void volume of at least 20% (v/v); and   a measurement device comprising a sensor interface, signal generator, and a processor, the signal generator providing an electrical input signal to the sensor interface, the processor being adapted to (i) direct the signal generator to provide the electrical input signal to the sensor interface, (ii) receive an output signal from the sensor interface, and (iii) measure the at least one output signal to obtain a current value from an excitation wherein the initial current is greater than those that follow in the decay and within less than 3 seconds of introducing the sample to the sensor strip.