Patent ID: 7604722

Claim:
An electrochemical biosensor comprising: (1) a hollow electrochemical cell for measuring a concentration of glucose in a blood sample, the hollow electrochemical cell comprising: (a) at least one non-metal working electrode; (b) at least one counter electrode or counter/reference electrode, wherein the working electrode and the counter electrode or counter/reference electrode face each other, are located on different planes, and are separated by a distance of from about 20 microns to about 200 microns; (c) a spacer interposed between the working electrode and the counter electrode or counter/reference electrode, wherein the spacer comprises a non-conductive polymeric material, and wherein the hollow electrochemical cell has an effective cell volume of less than 1.5 microliters; and (2) circuitry configured to determine the diffusion coefficient of a redox mediator in the cell, and independently its concentration, from cell current.