Patent ID: 8425758

Claim:
A method for determining a concentration of an analyte in a sample fluid, comprising the steps of: positioning a sensor in a sensor reader; contacting a sample fluid with a sensor, wherein the sensor comprises: a working electrode and a counter electrode; a first substrate having a proximal end and a distal end, the first substrate defining a first side edge and a second side edge of the electrochemical sensor extending from the proximal end to the distal end of the first substrate, the distal end being configured and arranged for insertion into a sensor reader; a second substrate disposed over the first substrate; a spacer comprising a first part and a second part disposed between the first and second substrates, wherein the first part of the spacer, the second part of the spacer, the first substrate, and the second substrate define a first aperture along the first side edge of the sensor and a second aperture along the second side edge of the sensor; a sample chamber for holding the sample fluid, the sample chamber comprising the working electrode, the counter electrode, an analyte-responsive enzyme and a redox mediator, wherein the sample chamber is sized to contain a volume of no more than about 1 μL of the sample fluid, and wherein the sample chamber has a length which extends from the first aperture to the second aperture and a substantially uniform width between the first part of the spacer and the second part of the spacer along the entire length of the sample chamber, and wherein the width of the sample chamber is not wider than either the first aperture or the second aperture; wherein following contacting the sample fluid with the sensor, the sensor reader: activates an auditory or a visual sign to alert a user when the sample chamber is sufficiently filled for initiating a reading; initiates a reading by generating a sensor signal at the working electrode, and determines the concentration of the analyte using the sensor signal.