Methods of determining analyte concentration having enhanced stability and hematocrit performance
First Claim
1. A method of determining the concentration of an analyte in a sample, comprising:
- applying a sample to an electrochemical sensor strip, the sensor strip including a first electrode, the first electrode including at least one first layer on a first conductor, the at least one first layer including an enzyme system and at most 8 μ
g/mm2 of a mediator,wherein the mediator assists in transferring electrons between an analyte in the sample and the first conductor;
applying a pulse sequence to the sample, the pulse sequence comprising at least 2 duty cycles within 3 to 14 seconds, wherein the at least 2 duty cycles each comprise an excitation, and the excitations are separated by a relaxation,wherein the relaxation provides an output current reduction to one-half or less of the current flow at the excitation maxima;
determining current measurements from the sample responsive to the pulse sequence; and
determining the concentration of the analyte in the sample from the current measurements, the determined concentration having at least one of a stability bias of less than ±
10%, a hematocrit bias of less than ±
10% for whole blood samples over a 20 to 60% hematocrit range, and an intercept to slope ratio of at most 20 mg/dL.
2 Assignments
0 Petitions
Accused Products
Abstract
The present invention relates to methods of determining the concentration of an analyte in a sample or improving the performance of a concentration determination. The electrochemical sensor strips may include at most 8 μg/mm2 of a mediator. The strips, the strip reagent layer, or the methods may provide for the determination of a concentration value having at least one of a stability bias of less than ±10% after storage at 50° C. for 4 weeks when compared to a comparison strip stored at −20° C. for 4 weeks, a hematocrit bias of less than ±10% for whole blood samples including from 20 to 60% hematocrit, and an intercept to slope ratio of at most 20 mg/dL.
-
Citations
21 Claims
-
1. A method of determining the concentration of an analyte in a sample, comprising:
-
applying a sample to an electrochemical sensor strip, the sensor strip including a first electrode, the first electrode including at least one first layer on a first conductor, the at least one first layer including an enzyme system and at most 8 μ
g/mm2 of a mediator,wherein the mediator assists in transferring electrons between an analyte in the sample and the first conductor; applying a pulse sequence to the sample, the pulse sequence comprising at least 2 duty cycles within 3 to 14 seconds, wherein the at least 2 duty cycles each comprise an excitation, and the excitations are separated by a relaxation, wherein the relaxation provides an output current reduction to one-half or less of the current flow at the excitation maxima; determining current measurements from the sample responsive to the pulse sequence; and determining the concentration of the analyte in the sample from the current measurements, the determined concentration having at least one of a stability bias of less than ±
10%, a hematocrit bias of less than ±
10% for whole blood samples over a 20 to 60% hematocrit range, and an intercept to slope ratio of at most 20 mg/dL. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
-
Specification