Methods and systems for insulin delivery and glucose measurement

An insulin delivery device configured to be inserted subcutaneously into a body of a subject via a single puncture site in said body of said subject,

• wherein said insulin delivery device is configured to deliver an insulin or insulin analog formulation to said subject via said single puncture site,
• wherein said insulin delivery device comprises an amperometric glucose sensor configured to measure a glucose concentration in said body of said subject via said single puncture site,
• wherein said amperometric glucose sensor comprises an electrode layer comprising at least one indicating electrode, wherein said electrode layer underlies a redox-catalytic layer comprising a redox mediator,
• wherein said redox mediator and an enzyme allow electron transfer from subcutaneous glucose to said at least one indicating electrode sufficient to cause a response of said amperometric glucose sensor to said subcutaneous glucose concentration at an applied bias potential of no more than +250 millivolts (mV) relative to a reference electrode, and
• wherein said delivering and said measuring are performed at the same time for a time period of at least one hour subsequent to said inserting, while maintaining a sensitivity of said sensor of at least 50% of an initial sensitivity of said sensor up to one hour subsequent to said inserting.