Patent ID: 7183068

Claim:
A method of manufacturing a collection assembly for use in a glucose sampling system and for electrochemical detection of an amount or concentration of glucose, the method comprising: providing a hydrogel comprising: polyethylene oxide present in an amount of about 5% to about 20% by weight based on the total weight of the hydrogel; water in an amount of about 50% or more and about 95% or less based on the total weight of the hydrogel; a chloride salt, wherein a background electrical signal in the gel is less than approximately 200 nA; a phosphate buffer in an amount sufficient to maintain a pH in the hydrogel in the range of 6 to 8; an enzyme composition comprising glucose oxidase, said glucose oxidase present in an amount of from about 10 units to about 5,000 units per gram of the total weight of the hydrogel; and a biocide comprising an undecylenate, wherein said hydrogel comprises a first surface and a second surface; contacting the first surface of the hydrogel with a mask layer, the mask layer comprising a material that is substantially impermeable to glucose or derivatives thereof, wherein the mask layer (i) has an inner face and an outer face, and the inner face is positioned in facing relationship with the first surface of the hydrogel, and (ii) defines a first opening that exposes at least a portion of the first surface of the hydrogel, and contacting the second surface of the hydrogel with a gel retaining layer, the gel retaining layer comprising an inner face and an outer face, wherein the inner face is positioned in facing relationship with the second surface of the hydrogel, and wherein the gel retaining layer defines a first opening that exposes at least a portion of the second surface of the hydrogel to complete the collection assembly.