Abstract: A test device and method for detecting or quantifying an analyte in a test sample employs an interdigitated electrode array and electroactive marker-encapsulating liposomes for signal generation and detection. The test device includes a contact portion on a first absorbent material, a capture portion either on the first absorbent material, or on a second absorbent material in fluid flow contact with the first absorbent material. The capture portion has a binding material specific for a portion of the analyte bound thereto. The device further includes an electrode array including first and second conductors each having a plurality of fingers, wherein the fingers of the conductors are interdigitated. The electrode array is positioned to induce redox cycling of an electroactive marker released either in or beyond the capture portion, depending upon whether direct (proportional) or indirect (inversely proportional) detection or measurement is desired.

Abstract: A test device for detecting or determining an analyte in a test solution includes an absorbent material having separate contact, competitive binding, and measurement portions. The contact portion is positioned for contact with and uptake of the test solution. The competitive binding portion has a binding material for the analyte non-diffusively bound thereto. The measurement portion has a receptor for the analyte and marker-encapsulating liposomes non-diffusively bound thereto. In a method for using the test device, a solution containing the analyte and the analyte-liposome conjugate is allowed to traverse the absorbent material from the contact portion through the competitive binding portion and on through the measurement portion of the absorbent material. The amount of marker in the measurement portion of the absorbent material, following traversal by the test solution, is then determined as a measure of the analyte in the sample.

Abstract: A test device for detecting or quantifying 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.

Abstract: A test device for detecting or quantifying an analyte in a test sample includes an absorbent material having separate contact and measurement portions. The contact portion is positioned at or proximate to a first end of the absorbent material. The measurement portion has a receptor for a conjugate of an analyte analog and marker-encapsulating liposomes. In a method for using the test device, a binding material specific for the analyte is combined with the liposome-analyte analog conjugate and the test sample to form a test mixture. The mixture is incubated for a time sufficient to permit competition between any analyte present and the conjugate for the binding material. Following incubation, the mixture is allowed to traverse the absorbent material from the contact portion through the measurement portion of the absorbent material.

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.

Abstract: A test device for detecting or determining an analyte in a test solution includes an absorbent material having separate contact, competitive binding, and measurement portions. The contact portion is positioned for contact with and uptake of the test solution. The competitive binding portion has a binding material for the analyte non-diffusively bound thereto. The measurement portion has a receptor for the analyte and marker-encapsulating liposomes non-diffusively bound thereto. In a method for using the test device, a solution containing the analyte and the analyte-liposome conjugate is allowed to traverse the absorbent material from the contact portion through the competitive binding portion and on through the measurement portion of the absorbent material. The amount of marker in the measurement portion of the absorbent material, following traversal by the test solution, is then determined as a measure of the analyte in the sample.

Abstract: A test device for detecting or quantifying an analyte in a test sample includes an absorbent material having separate contact and measurement portions. The contact portion is positioned at or proximate to a first end of the absorbent material. The measurement portion has a receptor for a conjugate of an analyte analog and marker-encapsulating liposomes. In a method for using the test device, a binding material specific for the analyte is combined with the liposome-analyte analog conjugate and the test sample to form a test mixture. The mixture is incubated for a time sufficient to permit competition between any analyte present and the conjugate for the binding material. Following incubation, the mixture is allowed to traverse the absorbent material from the contact portion through the measurement portion of the absorbent material.

Abstract: A test device for detecting or quantifying an analyte in a test sample includes an absorbent material having separate contact and measurement portions. The contact portion is positioned at or proximate to a first end of the absorbent material. The measurement portion has a receptor for a conjugate of an analyte analog and marker-encapsulating liposomes. In a method for using the test device, a binding material specific for the analyte is combined with the liposome-analyte analog conjugate and the test sample to form a test mixture. The mixture is incubated for a time sufficient to permit competition between any analyte present and the conjugate for the binding material. Following incubating, the mixture is allowed to traverse the absorbent material from the contact portion through the measurement portion of the absorbent material.