Zwitterion buffer containing compositions and uses in electroanalytical devices and methods

Abstract

Described herein are reagent compositions for detecting and/or measuring analytes in a test sample. In one embodiment, reagent compositions are described for detecting and/or measuring glucose in a sample.

1 .- 24 . (canceled) 
     
     
         25 . An electrochemical sensor comprising an electrode, and a hydratable matrix comprising a dried residue of (a) one or more enzymes selected from the group consisting of glucose dehydrogenases, glucose oxidoreductases, and combinations thereof; (b) optionally one or more co-factors, co-enzymes, or a combination thereof for the one or more enzymes; (c) one or more mediators, mediator precursors, or a combination thereof, wherein at least one mediator or mediator precursor is aqueous soluble; (d) one or more zwitterionic buffers; (e) one or more gelling or film forming agents, or a combination thereof; and (f) optionally one or more adjuvants. 
     
     
         26 . The reagent composition of  claim 25  wherein the enzyme is a wild-type GDH, or a mutant GDH. 
     
     
         27 . The reagent composition of  claim 25  wherein the enzyme is a GDH and the coenzyme is a FAD or a PQQ. 
     
     
         28 . The reagent composition of  claim 25  wherein the enzyme is a mutant GDH exhibiting maltose insensitivity. 
     
     
         29 . The reagent composition of  claim 25  wherein the enzyme is a mutant GDH exhibiting thermal stability. 
     
     
         30 . The reagent composition of  claim 25  wherein the zwitterionic buffer is PIPES or MOPS. 
     
     
         31 . The reagent composition of  claim 25  wherein the composition comprises a mediator precursor. 
     
     
         32 . The reagent composition of  claim 31  wherein the mediator precursor is a nitrosoaniline. 
     
     
         33 . The reagent composition of  claim 25  wherein the one or more adjuvants are selected from the group consisting of additional buffers, stabilizers, viscosity adjusting agents, thixotropic agents, dispersants, surfactants, detergents, pH adjusting agents, and combinations thereof. 
     
     
         34 . The reagent composition of  claim 25  wherein the film former is a polyvinyl acetate propionate co-polymer, polyvinyl propionate dispersions, or polyvinylpyrrolidone, or a combination thereof. 
     
     
         35 . The reagent composition of  claim 25  wherein at least one adjuvant is a viscosity modulator. 
     
     
         36 . The reagent composition of  claim 25  wherein at least one adjuvant is a dispersant. 
     
     
         37 . The reagent composition of  claim 25  wherein at least one adjuvant is an additional buffer. 
     
     
         38 . A test strip comprising a chamber, and the electrochemical sensor of  claim 25 , where the hydratable matrix and the electrode are located in the chamber. 
     
     
         39 . The test strip of  claim 38  wherein the chamber is formed from a base substrate and a covering layer overlying the base substrate; and where the chamber is disposed between the base substrate and the covering layer. 
     
     
         40 . The test strip of  claim 38  wherein the chamber includes a flared portion terminating in a fluid receiving opening and an elongated portion extending inwardly from the flared portion. 
     
     
         41 . The test strip of  claim 38  further comprising a vent in communication with the chamber, whereby air can escape from the vent as fluid is drawn into the chamber. 
     
     
         42 . The test strip of  claim 38  wherein the chamber has a volume less than or equal to 1.0 μL. 
     
     
         43 . The test strip of  claim 38  wherein the chamber has a volume less than or equal to 0.5 μL.