Cellulosic-based resistance domain for an analyte sensor

Abstract

The present invention relates generally to devices for measuring an analyte in a host. More particularly, the present invention relates to devices for measurement of glucose in a host that incorporate a cellulosic-based resistance domain.

What is claimed is: 
     
         1 . A method for forming an analyte sensor for measuring an analyte in a host, the method comprising:
 forming a membrane system on an electroactive surface, wherein the membrane system comprises a resistance domain configured to control a flux of the analyte therethrough, wherein the resistance domain is formed by applying a solution comprising at least one hydrophilic-hydrophobic macromolecule in a solvent system to the electroactive surface.   
     
     
         2 . The method of  claim 1 , wherein the membrane system is formed on the electroactive surface using a deposition technique selected from the group consisting of dip coating, spray coating, spin coating, and casting. 
     
     
         3 . The method of  claim 2 , wherein the resistance domain is formed by dip coating. 
     
     
         4 . The method of  claim 2 , further comprising the step of curing the resistance domain for at least about 2 minutes at ambient temperature. 
     
     
         5 . The method of  claim 2 , wherein the resistance domain is formed by dip coating an insertion rate of about 40 inches per minute. 
     
     
         6 . The method of  claim 2 , wherein the resistance domain is formed by dip coating at a dwell time of less than about 1 second. 
     
     
         7 . The method of  claim 2 , wherein the resistance domain is formed by dip coating at a withdrawal rate of about 40 inches per minute. 
     
     
         8 . The method of  claim 1 , wherein the membrane system further comprises an enzyme domain comprising a co-reactant, wherein the co-reactant is capable of undergoing a reaction with the analyte, and wherein the enzyme domain is formed prior to formation of the resistance domain. 
     
     
         9 . The method of  claim 1 , wherein the macromolecule comprises a cellulosic polymer. 
     
     
         10 . The method of  claim 9 , wherein the cellulosic polymer comprises cellulose acetate. 
     
     
         11 . The method of  claim 9 , wherein the cellulosic polymer comprises from about 3 wt. % to about 10 wt. % cellulose acetate. 
     
     
         12 . The method of  claim 9 , wherein the cellulosic polymer comprises about 7 wt. % cellulose acetate.