Patent ID: 7651596

Claim:
An electrochemical analyte sensor for measuring an analyte in a host, the sensor comprising: at least one electroactive surface; and a membrane system disposed on the electroactive surface, wherein the membrane system comprises: an electrode domain comprising a hydrophilic polymer; an interference domain disposed more distally from the electroactive surface than the electrode domain and comprising cellulose acetate and cellulose acetate butyrate, wherein the interference domain is configured to resist passage therethrough of at least one interferent, and wherein an equivalent glucose signal response of the at least one interferent is less than about 30 mg/dL; an enzyme domain disposed more distally from the electroactive surface than the interference domain; and a resistance domain disposed more distally from the electroactive surface than the enzyme domain, the resistance domain comprising a semipermeable membrane that controls a flux of oxygen and glucose to the underlying enzyme domain.