Patent ID: 7115362

Claim:
A process for preparing an electrochemical test device suitable for determining the presence or concentration of an analyte in an aqueous fluid sample, said process comprising the steps of: (a) providing a single substrate, the single substrate comprising a non-conductive coating affixed to one side of a flexible material; (b) depositing an amorphous semiconductor material on said non-conductive coating to form a conductive layer; (c) chemically machining the conductive layer to form a working electrode comprising a first electrode having a first electrode area, a first lead and a first contact pad, and to form a counter electrode comprising a second electrode having a second electrode area, a second lead and a second contact pad; and (d) applying a reagent to at least a portion of the first electrode area of the working electrode, said reagent being capable of reacting with an analyte in an aqueous fluid sample to produce a measurable change in potential which can be correlated to the concentration of the analyte in the fluid sample.