Disposable sub-microliter volume biosensor with enhanced sample inlet
First Claim
Patent Images
1. A disposable electrode strip for testing a fluid sample comprising:
- a laminated strip having a first strip end, a second strip end and a vent opening spaced from said first strip end, said laminated strip comprising a base layer having a conductive layer disposed thereon, said conductive layer having scribe lines delineated thereon and forming three electrode paths, a channel forming layer carried on said base layer, and a cover having an inlet notch at said first strip end;
an enclosed channel between said first strip end and said vent opening, said enclosed channel sized to hold a volume of said fluid sample less than one microliter;
a reagent matrix containing at least an enzyme, a stabilizer, wherein said stabilizer is a polyalkylene glycol, and a redox mediator disposed on said base layer in said enclosed channel;
conductive contacts at said second strip end and insulated from said enclosed channel.
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Accused Products
Abstract
A disposable electrode strip for testing a fluid sample including a laminated strip with a first and second end, a vent, an open path for receiving a fluid sample of less than one microliter beginning from the first end and connecting to the vent, a working electrode, a reference electrode and a pseudo-working electrode embedded in the laminated strip within the open path and proximate to the first end, a reagent matrix coextensive within the open path and covering the three electrodes, and conductive contacts located at the second end of the laminated strip.
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Citations
43 Claims
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1. A disposable electrode strip for testing a fluid sample comprising:
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a laminated strip having a first strip end, a second strip end and a vent opening spaced from said first strip end, said laminated strip comprising a base layer having a conductive layer disposed thereon, said conductive layer having scribe lines delineated thereon and forming three electrode paths, a channel forming layer carried on said base layer, and a cover having an inlet notch at said first strip end;
an enclosed channel between said first strip end and said vent opening, said enclosed channel sized to hold a volume of said fluid sample less than one microliter;
a reagent matrix containing at least an enzyme, a stabilizer, wherein said stabilizer is a polyalkylene glycol, and a redox mediator disposed on said base layer in said enclosed channel;
conductive contacts at said second strip end and insulated from said enclosed channel. - 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)
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25. A disposable electrode strip for detecting or measuring the concentration of an analyte in a fluid sample, said electrode strip comprising:
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an insulating base strip having a first base end and a second base end;
a conductive layer disposed on one side of said base strip, said conductive layer having a pattern scribed into said conductive layer, said pattern delineating three electrically-distinct conductive paths insulated from each other;
a middle insulator sized smaller than said insulating base strip and overlaying a substantial portion of said conductive layer, said middle insulator having a cutout portion spaced from said first base end, said cutout portion exposing a limited area of said three conductive paths;
an electrode material comprising an enzyme, a redox mediator, a stabilizer wherein said stabilizer is a polyalkylene glycol, a binder, a surfactant, and a buffer, said electrode material being disposed in said cutout portion; and
a covering insulator sized to fit over and be coextensive with said middle insulator creating a sample fluid channel, said covering insulator having an inlet notch at a first covering insulator end, said first covering insulator end being coextensive with said first base end, and a covering insulator aperture spaced from said first base end and configured to expose at least a small portion of said cutout portion of said middle insulator. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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37. A method of making a disposable biosensor comprising:
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scribing a plurality of scribe lines into a conductive coating disposed on one side of an elongated base layer having an electrode end and an electrical contact end forming three elongated electrical conduits along the length of said base layer wherein said plurality of scribe lines delineates a first conduit of said three electrical conduits having an L-shape, a second conduit having a mirror-image L-shape wherein the L-shaped portions of said first and second conduits are adjacent to each other, and a third conduit shorter than either of said first and second conduits and having a straight elongated shape wherein said L-shaped ends of said first and second conduits and the end of said third conduit are in axial alignment with the central axis of the length of said base layer and are located near said electrode end;
disposing a channel forming layer over said conductive coating of said base layer, said channel forming layer having a U-shaped end portion defining a central elongated channel sized to expose a portion of each of said L-shaped ends of said first and second conduits and a portion of said third conduit, said channel forming layer being shorter in length than said base layer such that a portion of each of said three elongated conduits is exposed at said electrical contact end;
adding a reagent mixture to said central channel covering said exposed portions of said first, second and third conduits, said reagent mixture having an enzyme capable of catalyzing a reaction involving a substrate for the enzyme;
drying said reagent mixture; and
disposing a top layer over said channel forming layer, said top layer having a vent opening spaced from said electrode end, said top layer forming an inlet and a capillary space with said U-shaped end portion wherein said vent exposes a portion of said central channel at the end of said capillary space opposite said inlet. - View Dependent Claims (38, 39)
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40. A method of making multiple, disposable sensors wherein each sensor has at least a working electrode, a reference electrode, a pseudo-working electrode, and a reagent matrix, wherein said reagent matrix contains an enzyme capable of catalyzing a reaction involving a substrate for the enzyme, said working electrode and said reference electrode being disposed in a fluid sample channel for measuring a fluid sample, said method comprising:
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obtaining a base strip of an insulating material having a layer of conductive material disposed thereon, said base strip having a first edge and a second edge;
scribing in said conductive material a plurality of lines in a repetitive pattern wherein said plurality of lines contain a repetitive pattern capable of forming three conductive paths in each of said repetitive pattern;
disposing a middle layer of insulating material over said base strip, said middle layer having a repetitive pattern of an elongated cutout wherein each cutout of each of said repetitive pattern exposes an electrode portion of each of said three conductive paths of each repetitive pattern wherein said repetitive pattern of said elongated cutout are spaced from said first edge of said base strip, and wherein said middle layer is sized to expose a contact portion of each of said two conductive paths of each repetitive pattern for a distance from said second edge of said base strip;
disposing a reagent material into each elongated cutout of said repetitive pattern wherein said reagent material contains a polyalkylene glycol stabilizer;
drying said reagent material at a temperature and for a length of time sufficient to solidify said reagent material in each of said elongated cutout;
disposing a top layer of insulating material over and coextensive with said middle layer, said top layer having a plurality of vent openings and notch forming holes in a repetitive pattern wherein each of said vent openings exposes a portion of a corresponding repetitive pattern of said elongated cutout of said middle layer furthest from said first edge of said base strip and wherein each of said notch forming holes exposes a portion of said corresponding repetitive pattern of said elongated cutout portion closest to said first edge of said base strip, said base strip, said middle layer and said top layer forming a laminated strip;
cutting along and parallel to said first edge of said laminated strip a predetermined distance creating a sample inlet port in each of said elongated cutout and an inlet notch in said top layer for each of said repetitive pattern;
cutting along and parallel to said second edge of said laminated strip a predetermined distance creating two separate contacts for each of said repetitive pattern; and
separating each of said repetitive pattern at predetermined intervals along said laminated strip. - View Dependent Claims (41)
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42. A laminated biosensor strip comprising:
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a base layer with an electrode end and an electrical contact end, said base layer having an electrically conductive coating on one side wherein said conductive coating has a plurality of scribed lines delineating a first conduit having an L-shape, a second conduit having a mirror-image L-shape wherein the L-shape ends of said first and second conduits are adjacent to each other, and a third conduit which is shorter than either of said first and second conduits, has a linear, elongated shape wherein said L-shaped ends of said first and second conduits and the end of said third conduit are aligned with each other along the central axis of said base layer;
a channel forming layer disposed over said base layer, said channel forming layer having a U-shaped end portion defining a central elongated channel sized to expose a portion of each of said L-shaped ends of said first and second conduits and a portion of said third conduit, said channel forming layer being shorter in length than said base layer wherein a portion of each of said three conduits is exposed at said electrical contact end;
a reagent material having at least a redox mediator and an enzyme disposed within said U-shaped end portion and covering the exposed portions of said first, second and third conduits; and
a cover with a vent, said cover disposed on and coextensive with said channel forming layer, said cover, said channel forming layer and said base layer forming a capillary channel with an inlet at one end and communicating with said vent at the other end. - View Dependent Claims (43)
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Specification