Small volume in vitro analyte sensor
First Claim
1. A method for determining a concentration of an analyte in a body fluid of a patient, comprising the steps of:
- creating a flow of a body fluid from forearm skin of a patient;
transporting no more than 1000 nl of the body fluid into an analyte sensor comprising a sample chamber, the sample chamber having a volume of no more than 1000 nl and comprising a redox mediator and at least two electrodes including a working electrode and a reference and/or counter electrode, wherein said sensor is configured and arranged for determining the concentration of the analyte from no more than 1000 nL of body fluid;
holding the sample within the sample chamber in a non-flow-through manner; and
determining by coulometry the concentration of the analyte in the body fluid.
3 Assignments
0 Petitions
Accused Products
Abstract
A sensor designed to determine the amount and concentration of analyte in a sample having a volume of less than about 1 μL. The sensor has a working electrode coated with a non-leachable redox mediator. The redox mediator acts as an electron transfer agent between the analyte and the electrode. In addition, a second electron transfer agent, such as an enzyme, can be added to facilitate the electrooxidation or electroreduction of the analyte. The redox mediator is typically a redox compound bound to a polymer. The preferred redox mediators are air-oxidizable.
The amount of analyte can be determined by coulometry. One particular coulometric technique includes the measurement of the current between the working electrode and a counter or reference electrode at two or more times. The charge passed by this current to or from the analyte is correlated with the amount of analyte in the sample. Other electrochemical detection methods, such as amperometric, voltammetric, and potentiometric techniques, can also be used.
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. An enzyme capable of catalyzing the electrooxidation or electroreduction of the biomolecule is provided as a second electron transfer agent.
460 Citations
77 Claims
-
1. A method for determining a concentration of an analyte in a body fluid of a patient, comprising the steps of:
-
creating a flow of a body fluid from forearm skin of a patient; transporting no more than 1000 nl of the body fluid into an analyte sensor comprising a sample chamber, the sample chamber having a volume of no more than 1000 nl and comprising a redox mediator and at least two electrodes including a working electrode and a reference and/or counter electrode, wherein said sensor is configured and arranged for determining the concentration of the analyte from no more than 1000 nL of body fluid; holding the sample within the sample chamber in a non-flow-through manner; and determining by coulometry the concentration of the analyte in the body fluid. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
-
-
31. A method for determining a concentration of an analyte in a body fluid of a patient, comprising the steps of:
-
creating a flow of a body fluid from forearm skin of a patient; transporting no more than 1000 nl the body fluid into an analyte sensor comprising a sample chamber, the sample chamber having a volume of no more than 1000 nl and comprising a redox mediator and at least two electrodes including a working electrode and a reference and/or counter electrode separated by a distance of no greater than 1000 microns, wherein said sensor is configured and arranged for determining the concentration of the analyte from no more than 1000 nL of body fluid; holding the sample within the sample chamber in a non-flow-through manner; and determining by coulometry the concentration of the analyte in the body fluid. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54)
-
-
55. A method for determining a concentration of an analyte in a body fluid of a patient, comprising the steps of:
-
creating a flow of a body fluid from forearm skin of a patient; transporting no more than 1000 nl of the body fluid into an analyte sensor comprising a sample chamber, the sample chamber having a volume of no more than 1000 nl and comprising a redox mediator and at least two electrodes including a working electrode and a reference and/or counter electrode disposed in a coplanar configuration, wherein said sensor is configured and arranged for determining the concentration of the analyte from no more than 1000 nL of body fluid; holding the sample within the sample chamber in a non-flow-through manner; and determining by coulometry the concentration of the analyte in the body fluid. - View Dependent Claims (56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77)
-
Specification