Analyte sensors employing multiple enzymes and methods associated therewith

An analyte sensor for detecting glucose and ketones in vivo, the sensor comprising:

• at least a first working electrode and a second working electrode;
• a ketones-responsive active area disposed upon a surface of the first working electrode;
• a glucose-responsive active area disposed upon a surface of the second working electrode;
• a mass transport limiting membrane overcoating the ketones-responsive active area and the glucose-responsive active area;
• wherein:
• (i) one or more of an area, a size, or an areal ratio of the glucose-responsive area and the ketones-responsive active area vary with respect to one another;
• (ii) the mass transport limiting membrane has a thickness over the ketones-responsive active area that differs from a thickness of the mass transport limiting membrane over the glucose-responsive active area;
• or
• (iii) both (i) and (ii);
• wherein (i), (ii), and (iii) provide independent variation of analyte sensitivity at each working electrode, and
• wherein the sensor is configured to be partially inserted into a user's skin such that a distal portion of the sensor is in contact with an interstitial fluid to detect glucose and ketones in vivo.