Rapid analyte measurement assay
View Patent ↗The present the invention provides methods, devices and systems for rapidly measuring analytes within a biological sample.
1. A method of measuring concentration of a target analyte in a sample, the method comprising:
contacting a sample of no more than 1 μL comprising the target analyte with a test strip comprising a working electrode; a counter electrode; and a redox reagent system, the redox reagent system comprising a first redox couple and a secondary redox couple, wherein the first redox couple is selected and configured to mediate the target analyte in the sample;
applying a square wave excitation voltage to the test strip;
measuring a response current from the test strip, wherein the response current comprises a primary peak associated with mediation of the target analyte by the first redox couple and a secondary peak from the secondary redox couple; and
determining the concentration of the target analyte from the no more than 1 μL of sample based on the primary and secondary peaks.
2. The method of claim 1 , wherein the secondary peak comprises a response current in response to a hematocrit level of the sample.
3. The method of claim 1 , wherein the secondary peak comprises a response current in response to the temperature of the sample.
4. The method of claim 1 , wherein measuring the response current further comprises:
decoupling the first peak from the secondary peak; and
correcting the first peak using the secondary peak.
5. The method of claim 1 , wherein the target analyte is glucose.
6. The method of claim 1 , wherein determining the concentration of the target analyte is performed within less than 1 second.
7. A method of measuring the concentration of glucose in a sample, the method comprising:
contacting a sample of no more than 1 μL comprising glucose with a test strip comprising a working electrode; a counter electrode; and a redox reagent system, the redox reagent system comprising a first redox couple and a secondary redox couple, wherein the first redox couple is selected and configured to mediate glucose in the sample;
applying a square wave excitation voltage to the test strip;
measuring a response current, wherein the response current comprises a primary peak from mediation of glucose by the first redox couple and a secondary peak from the secondary redox couple; and
determining the concentration of glucose from the no more than 1 μL of sample within less than 1 second based on the first and second peaks.
8. The method of claim 1 , wherein measuring the response current comprises measuring a value of the primary peak and a value of the secondary peak and correcting the value of the primary peak based on the value of the secondary peak.
9. The method of claim 2 , wherein the primary and secondary peaks are similarly affected by the hematocrit level of the sample.
10. The method of claim 3 , wherein the primary and secondary peaks are similarly affected by the temperature of the sample.
11. The method of claim 1 , wherein the square wave is superimposed over a potential step function to provide a potential waveform.
12. The method of claim 1 , wherein the square wave excitation voltage is applied at a frequency not less than about 100 Hz and scanned across range of about 1 volt.
13. The method of claim 1 , wherein the redox reagent system comprises another secondary redox couple.
14. The method of claim 7 , wherein measuring the response current comprises measuring a value of the primary peak and a value of the secondary peak and correcting the value of the primary peak based on the value of the secondary peak.
15. The method of claim 7 , wherein the secondary peak comprise a response current in response to a hematocrit level of the sample and the primary and secondary peaks are similarly affected by the hematocrit level of the sample.
16. The method of claim 7 , wherein the secondary peak comprise a response current in response to the temperature of the sample and the primary and secondary peaks are similarly affected by the temperature of the sample.
17. The method of claim 7 , wherein the square wave is superimposed over a potential step function to provide a potential waveform.
18. The method of claim 7 , wherein the square wave excitation voltage is applied at a frequency not less than about 100 Hz and scanned across range of about 1 volt.
19. The method of claim 7 , wherein the redox reagent system comprises another secondary redox couple.