	US 12,446,802 B2
	Diffusion layer for an enzymatic in-vivo sensor
Gregor Ocvirk, Mannheim (DE); Angelika Fuerst, Mannheim (DE); Alexander Steck, Mannheim (DE); and Juergen Woehrle, Mannheim (DE)
Assigned to Roche Diabetes Care, Inc., Indianapolis, IN (US)
Filed by Roche Diabetes Care, Inc., Indianapolis, IN (US)
Filed on Nov. 3, 2020, as Appl. No. 17/088,329.
Application 17/088,329 is a continuation of application No. PCT/EP2019/061177, filed on May 2, 2019.
Claims priority of application No. 18170896 (EP), filed on May 4, 2018.
Prior Publication US 2021/0045664 A1, Feb. 18, 2021
Int. Cl. A61B 5/145 (2006.01); A61B 5/1486 (2006.01); B01D 69/02 (2006.01); B01D 71/40 (2006.01); B01D 71/80 (2006.01); C12N 11/087 (2020.01); C12Q 1/00 (2006.01); C08L 33/10 (2006.01)

CPC A61B 5/14532 (2013.01) [A61B 5/1486 (2013.01); B01D 69/02 (2013.01); B01D 71/401 (2022.08); B01D 71/80 (2013.01); C12N 11/087 (2020.01); C12Q 1/002 (2013.01); C12Q 1/006 (2013.01); B01D 2323/12 (2013.01); B01D 2325/32 (2013.01); B01D 2325/34 (2013.01); B01D 2325/36 (2013.01); C08L 33/10 (2013.01)]

16 Claims

1. An electrode system for measuring the concentration of an analyte under in-vivo conditions, comprising:

an electrode having immobilized enzyme molecules and a diffusion barrier configured to control diffusion of the analyte from the exterior of the electrode system to the enzyme molecules;

the diffusion barrier comprising a block copolymer having from 75 to 95 mol % of a 2-hydroxyethyl methacrylate (HEMA) block and from 5 to 25 mol % of a hydrophobic block of n-butyl acrylate (n-BuA) or ethyl acrylate (EA), based on the total amount (mol) of the block copolymer in a dry state;

wherein the glass transition temperature of the hydrophobic block of the n-BuA or EA is in the range of about −80° C. and about 0° C.; and

wherein subjecting a sensor having the electrode system to a 1 mm bending radius avoids indicia of Newton's Rings and/or a sensor having the electrode system has a sensitivity in the range of 1 to 1.5 nA/mM analyte.