Small volume in vitro analyte sensor
First Claim
1. A method for determining the concentration of glucose in a biological fluid sample from a subject, comprising the steps of:
- providing a sensor comprising a working electrode, a counter electrode and a sample chamber sized to contain no more than about 1 μ
L of sample, wherein the sample chamber comprises a redox mediator and an analyte responsive enzyme disposed on the working electrode, the redox mediator comprising;
a transition metal selected from the group consisting of osmium, ruthenium, iron, and cobalt;
two or more ligands coordinately bound to the transition metal, wherein at least one of the ligands is a monodentate ligand that is a monosubstituted pyridine, and wherein at least one of the ligands is a heterocyclic nitrogen-containing bidentate ligand comprising
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Accused Products
Abstract
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.
497 Citations
32 Claims
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1. A method for determining the concentration of glucose in a biological fluid sample from a subject, comprising the steps of:
providing a sensor comprising a working electrode, a counter electrode and a sample chamber sized to contain no more than about 1 μ
L of sample, wherein the sample chamber comprises a redox mediator and an analyte responsive enzyme disposed on the working electrode, the redox mediator comprising;a transition metal selected from the group consisting of osmium, ruthenium, iron, and cobalt; two or more ligands coordinately bound to the transition metal, wherein at least one of the ligands is a monodentate ligand that is a monosubstituted pyridine, and wherein at least one of the ligands is a heterocyclic nitrogen-containing bidentate ligand comprising - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A system for determining the concentration of glucose in a biological fluid sample, the system comprising:
(a) a sensor comprising a working electrode, a counter electrode, and a sample chamber sized to contain no more than about 1 μ
L of sample, wherein the sample chamber comprises a redox mediator and an analyte responsive enzyme disposed on the working electrode, the redox mediator comprising;a transition metal selected from the group consisting of osmium, ruthenium, iron, and cobalt; two or more ligands coordinately bound to the transition metal, wherein at least one of the ligands is a monodentate ligand that is a monosubstituted pyridine, and wherein at least one of the ligands is a heterocyclic nitrogen-containing bidentate ligand comprising - View Dependent Claims (19, 20, 21, 22, 23)
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24. The system of claim 18, wherein said working electrode and said counter electrode are facing each other.
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25. The system of claim 18, wherein said working electrode and said counter electrode are side by side.
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26. The system of claim 18, wherein said working electrode is spaced no more than 1000 microns from said counter electrode.
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27. The system of claim 18, wherein said analyte responsive enzyme is glucose oxidase or glucose dehydrogenase.
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28. The system of claim 18, wherein said sensor electrolyzes at least 20% of said sample.
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29. The system of claim 18, wherein the transition metal is osmium.
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30. The system of claim 18, wherein R1 is an alkyl.
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31. The system of claim 30, wherein R1 is methyl.
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32. The system of claim 18, wherein at least one of the ligands is a unsubstituted pyridine.
Specification