Small volume in vitro analyte sensor

摘要

A sensor utilizing a non-leachable or diffusible redox mediator is described. The sensor includes a sample chamber to hold a sample in electrolytic contact with a working electrode, and in at least some instances, the sensor also contains a non-leachable or a diffusible second electron transfer agent. The sensor and/or the methods used produce a sensor signal in response to the analyte that can be distinguished from a background signal caused by the mediator. The invention can be used to determine the concentration of a biomolecule, such as glucose or lactate, in a biological fluid, such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. An enzyme capable of catalyzing the electrooxidation or electroreduction of the biomolecule is typically provided as a second electron transfer agent.

主权项

1. A method of using a blood glucose meter, comprising:
contacting a blood sample with a sensor positioned in the blood glucose meter, wherein the sensor comprises:
a first electrode, a second electrode, and a third electrode;a sample chamber for holding the blood sample, the sample chamber comprising the first electrode, the second electrode, and the third electrode; anda glucose-responsive enzyme and a redox mediator disposed in the sample chamber; applying a first potential between the first and second electrodes using the blood glucose meter and detecting a change in an electrical signal between the first and second electrodes to determine when the blood sample contacts the first and second electrodes; applying a second potential between the first and third electrodes using the blood glucose meter and determining whether a change in an electrical signal occurs between the first and third electrodes to determine whether the blood sample contacts the first and third electrodes; and determining partial filling of the sample chamber by the blood sample when a change in an electrical signal occurs between the first and second electrodes and when a change in an electrical signal does not occur between the first and third electrodes.