Patent ID: 8758582

Claim:
A method for detecting an analyte in a sample comprising the steps of: introducing the sample into a test cell of an electrochemical test strip for detection of the analyte comprising: a first insulating substrate layer, a second substrate layer, and an intervening insulating spacer layer, wherein (a) an opening in the insulating spacer layer defines the test cell which is in contact with the inner surface of the first substrate on one side and the inner surface of the second substrate on the other side; and (b) the size of the test cell is determined by the area of the first and second substrates exposed and the thickness of the spacer layer; working and counter electrodes appropriate for the analyte to be detected disposed on the first insulating substrate in a location within the test cell, said working and counter electrodes being associated with conductive leads that allow connection of the electrodes to a meter for determination of analyte; wherein a region of the second substrate facing the working and counter electrodes is conductive and has no connector for connection with a meter for determination of analyte; wherein a redox mediator is disposed in the test cell; applying a potential between the working and counter electrodes, but not to the conductive region of the second substrate, thereby reducing an oxidized form of the redox mediator at the counter electrode and oxidizing a reduced form of the redox mediator at the working electrode, thereby generating a current indicative of analyte in the sample; wherein the overall transfer of electrons from the counter electrode to the working electrode is accomplished by diffusion of reduced mediator from the counter electrode to the conductive region of the second substrate and then diffusion of reduced mediator from the conductive region of the second substrate to the working electrode, and measuring the current to obtain a determination of analyte in the sample.