Membrane for continuous analyte sensors

Abstract

Devices are presented for measurement of an analyte concentration. The devices comprise: a sensor configured to generate a signal indicative of a concentration of an analyte; and a sensing membrane located over the sensor. The sensing membrane comprises an enzyme domain comprising an enzyme, a base polymer, and a hydrophilic polymer which makes up from about 5 wt. % to about 30 wt. % of the enzyme domain.

1 - 20 . (canceled) 
     
     
         21 . A device for measurement of an analyte concentration, the device comprising:
 an in vivo sensor configured to generate a signal indicative of a concentration of an analyte; and   a membrane located over the sensor, the membrane comprising:   a first domain that interfaces with tissue and/or a biological fluid;   a second domain, wherein the second domain comprises an enzyme and a zwitterion.   
     
     
         22 . The device of  claim 21 , wherein the zwitterion comprises a betaine or a derivative thereof. 
     
     
         23 . The device of  claim 22 , wherein the betaine or derivative thereof is selected from the group consisting of cocamidopropyl betaine, oleamidopropyl betaine, lauryl sulfobetaine, myristyl sulfobetaine, betaine, octyl betaine, glycine betaine, poly(carboxybetaine), poly(sulfobetaine), and derivatives thereof. 
     
     
         24 . The device of  claim 21 , wherein the second domain comprises a base polymer. 
     
     
         25 . The device of  claim 25 , where the base polymer is cross-linked with another base polymer. 
     
     
         26 . The device of  claim 25 , wherein the base polymer is selected from the group consisting of epoxies, polyolefins, polysiloxanes, polyethers, acrylics, polyesters, carbonates, and polyurethanes. 
     
     
         27 . The device of  claim 25 , wherein the polyurethanes comprise polyurethane copolymers. 
     
     
         28 . The device of  claim 21 , wherein the enzyme is selected from the group consisting of glucose oxidase, glucose dehydrogenase, galactose oxidase, cholesterol oxidase, amino acid oxidase, alcohol oxidase, lactate oxidase, and uricase. 
     
     
         29 . The device of  claim 21 , wherein the second domain is from about 0.05 micron to about 5 microns. 
     
     
         30 . The device of  claim 21 , wherein the sensor comprises an electrode.