Patent ID: 7657297

Claim:
An electrochemical glucose sensor comprising a three-electrode system, the sensor comprising: an electrochemical cell comprising a working electrode, reference electrode, and counter electrode; and a potentiostat that controls the potential between the working and reference electrodes, wherein the potentiostat sets a low voltage limit at which the counter electrode of the glucose sensor reacts with reducible species, other than oxygen, when oxygen becomes limited and at which no substantial bubble formation occurs, wherein the potentiostat comprises an operational amplifier comprising: (i) a first input coupled to the reference electrode; (ii) a second input coupled to a reference voltage source; and (iii) an output coupled to the counter electrode, wherein the reference voltage source is set to a voltage value relative to battery ground such that the low voltage limit at the counter electrode causes the counter electrode to react with reducible species, other than oxygen, when oxygen becomes limited, and substantial bubble formation does not occur at the counter electrode.