Interdigitated electrode arrays for liposome-enhanced immunoassay and test device
First Claim
1. A test device for detecting or quantifying an analyte in a test sample, said test device comprising an absorbent material, said absorbent material comprising:
- a contact portion at or proximate to a first end of said absorbent material;
an electrochemical measurement portion at a location on said absorbent material which is positioned away from the first end, wherein said electrochemical measurement portion comprises an electrochemical detector cell consisting of a first conductor comprising a plurality of fingers disposed on said absorbent material and a second conductor comprising a plurality of fingers disposed on said absorbent material, wherein said fingers of said first conductor are interdigitated with said fingers of said second conductor, and wherein said conductors induce redox cycling; and
a liposome lysing portion segregated from said contact portion and having a liposome lysing agent bound thereto, wherein said liposome lysing portion either is positioned between said contact portion and said electrochemical measurement portion, or partially or completely coincides with said electrochemical measurement portion.
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Accused Products
Abstract
A test device for detecting or determining an analyte in a test solution includes an absorbent material having contact, liposome lysing and electrochemical measurement portions. The contact portion is positioned for contact with and uptake of the test solution. The liposome lysing portion is segregated from the contact portion and has a liposome lysing agent bound thereto. The liposome lysing portion is further either positioned between the contact portion and the electrochemical measurement portion, or partially or completely coincides with the electrochemical measurement portion. The electrochemical measurement portion comprises a first conductor comprising a plurality of fingers disposed on the absorbent material, and a second conductor similarly comprising a plurality of fingers disposed on the absorbent material, where the fingers of the first and second conductors are interdigitated to form an array.
96 Citations
43 Claims
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1. A test device for detecting or quantifying an analyte in a test sample, said test device comprising an absorbent material, said absorbent material comprising:
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a contact portion at or proximate to a first end of said absorbent material; an electrochemical measurement portion at a location on said absorbent material which is positioned away from the first end, wherein said electrochemical measurement portion comprises an electrochemical detector cell consisting of a first conductor comprising a plurality of fingers disposed on said absorbent material and a second conductor comprising a plurality of fingers disposed on said absorbent material, wherein said fingers of said first conductor are interdigitated with said fingers of said second conductor, and wherein said conductors induce redox cycling; and a liposome lysing portion segregated from said contact portion and having a liposome lysing agent bound thereto, wherein said liposome lysing portion either is positioned between said contact portion and said electrochemical measurement portion, or partially or completely coincides with said electrochemical measurement portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method for detecting or quantifying an analyte in a test sample, comprising:
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providing a test device comprising an absorbent material, said absorbent material comprising; a contact portion at or proximate to a first end of said absorbent material; an electrochemical measurement portion at a location on said absorbent material which is positioned away from the first end, wherein said electrochemical measurement portion comprises an electrochemical detector cell consisting of a first conductor comprising a plurality of fingers disposed on said absorbent material and a second conductor comprising a plurality of fingers disposed on said absorbent material, wherein said fingers of said first conductor are interdigitated with said fingers of said second conductor and wherein said first conductor and said second conductor are electrically connected to one another; and a liposome lysing portion segregated from said contact portion and having a liposome lysing agent bound thereto, wherein said liposome lysing portion either is positioned between said contact portion and said electrochemical measurement portion, or partially or completely coincides with said electrochemical measurement portion; combining a binding material specific for the analyte with a conjugate of an analyte analog and liposomes and the test sample in an electrolyte mixture, wherein said liposomes comprise an electroactive marker; incubating the mixture for a time sufficient to permit competition between any analyte present in the test sample and the conjugate for the binding material; contacting the mixture with said contact portion of said absorbent material after said incubating; applying a potential to said conductors, wherein said potential is sufficient to induce redox cycling of said marker; allowing the mixture to migrate from said contact portion through said electrochemical measurement portion of said absorbent material after said incubating, wherein migration of aggregates of conjugate and binding material formed during said incubating is inhibited by said absorbent material, and whereby said liposomes are lysed by said liposome lysing agent to release said marker, and said marker undergoes redox cycling induced by said conductors causing current to flow between said first and second conductors; detecting the presence or amount of said current; and correlating the presence or amount of said current with the presence or amount, respectively, of the analyte in the test sample. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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32. A method for detecting or quantifying an analyte in a test sample, comprising:
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providing a test device comprising an absorbent material, said absorbent material comprising; a contact portion at or proximate to a first end of said absorbent material; an electrochemical measurement portion at a location on said absorbent material which is positioned away from the first end, wherein said electrochemical measurement portion comprises an electrochemical detector cell consisting of a first conductor comprising a plurality of fingers disposed on said absorbent material and a second conductor comprising a plurality of fingers disposed on said absorbent material, wherein said fingers of said first conductor are interdigitated with said fingers of said second conductor and wherein said first conductor and said second conductor are electrically connected to one another; a liposome lysing portion segregated from said contact portion and having a liposome lysing agent bound thereto, wherein said liposome lysing portion either is positioned between said contact portion and said electrochemical measurement portion, or partially or completely coincides with said electrochemical measurement portion; and a competitive binding portion positioned between and segregated from said contact and said liposome lysing portions on said absorbent material and having a binding material for the analyte bound to said competitive binding portion; contacting an electrolytic mixture of the test sample and a conjugate of an analyte analog and liposomes with said contact portion of said absorbent material, wherein said liposomes comprise an electroactive marker; applying a potential to said conductors, wherein said potential is sufficient to induce redox cycling of said marker; allowing the mixture to migrate from said contact portion through said electrochemical measurement portion of said absorbent material, whereby said liposomes are lysed by said liposome lysing agent to release said marker, and said marker undergoes redox cycling induced by said conductors causing current to flow between said first and second conductors; detecting the presence or amount of said current; and correlating the presence or amount of said current with the presence or amount, respectively, of the analyte in the test sample. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43)
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Specification