Biosensor

• US 7,455,756 B2
• Filed: 05/30/2002
• Issued: 11/25/2008
• Est. Priority Date: 05/30/2001
• Status: Expired due to Fees

• Current Assignee: i-SENS, Inc.
• Original Assignee: i-SENS, Inc.
• Inventors: Nam, Hakhyun, Cha, Geun-Sig, Cui, Gang, Kim, Min-Sun, Yoo, Jae-Hyun, Choi, Moon-Hee, Cho, Ho-Choll, Zhang, Fenghua
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US10/476,634
• Publication Number:
  US 20040140209A1
• Time in Patent Office: 2,371 Days
• Field of Search: 20440301-40315
• US Class Current: 204/403.01
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: G01N 33/5438 Electrodes

Abstract

A biosensor, for use in measurement of an analyte, includes a microporous membrane support, a first electrode system, a second electrode system, and a pair of insulating films. The first electrode system is formed on the surface of the microporous membrane support and the second electrode system is formed on the opposite surface of the microporous membrane support. The biosensor enables a rapid, simple, separation-free, and selective detection of the analytes. The biosensor does not require any bulky additional electrode, so that miniaturization, point-of-car testing, and disposability can be achieved.

Claims

1. A biosensor for separation-free enzyme immunoassays without washing, comprising:

a microporous membrane support;

a first electrode system consisting of a working electrode on which antibodies are immobilized, a first electrode connector, and a first lead outlet;

a second electrode system consisting of a counter electrode, a second electrode connector and a second lead outlet;

a pair of insulating films, covering surfaces of the first and second electrode systems except for the areas of the working electrode, the first electrode connector, the counter electrode and the second electrode connector; and

a pad containing an enzyme-antibody conjugate on the top of the working electrode, and

a pair of covers consisting of an upper cover having a hole and a lower cover having a hole,

wherein, the first electrode system is formed on the surface of the microporous membrane support and the second electrode system is formed on the opposite surface of the microporous membrane support,

wherein, the working electrode and the counter electrode are formed directly on the microporous membrane support,

whereby the electrodes being microporous and allowing a sample liquid to pass through the surface of the working electrode to the surface of the counter electrode and a substrate to pass through the surface of the counter electrode to the surface of the working electrode,

wherein a sample solution containing an analyte, introduced into the hole of the upper cover, reacts to form a bound enzyme-antibody conjugate with the antibodies and an unbound enzyme-antibody conjugate, the bound enzyme-antibody conjugate being formed in the working electrode, and

wherein the substrate participates in the enzyme reaction with the enzyme from the bound enzyme-antibody conjugate to generate electrons transferable to the electrode and the unbound enzyme-antibody conjugate to generate electrons not transferable to the electrode.

2. The biosensor as set forth in claim 1, wherein the counter electrode is made of an electrically conductive material symmetrically to the working electrode.

3. The biosensor as set forth in claim 2, wherein the electrically conductive material is selected from the group consisting of gold, platinum, silver, silver chloride, rhodium, iridium, ruthenium, palladium, osmium, carbon, copper, and mixtures thereof.

4. The biosensor as set forth in claim 1, wherein the counter electrode is made of an electrically conductive material asymmetrically to the working electrode.

5. The biosensors as set forth in claim 2 or 4, wherein the first and second insulating films contain separately formed electrical connectors, and wherein the symmetric or asymmetric double-sided electrodes are sandwiched between the insulating films and connected to the connectors of insulating films.

6. The biosensor as set forth in claim 1, wherein the first and second lead outlets and connectors are separated from each other.

7. The biosensor as set forth in claim 1, the microporous membrane support is made of a member selected from the group consisting of an organic polymer, inorganic polymer, natural fabrics or synthetic fibers, papers and ceramics.

8. The biosensor as set forth in claim 1, wherein the microporous membrane support is a microporous nylon mesh.

9. The biosensor as set forth in claim 1, further comprising a pad containing the substrate below the counter electrode.

10. The biosensor as set forth in claims 1 or 9, further comprising a filter pad between the pad on the top of the working electrode and the upper cover.

11. The biosensor as set forth in claim 10, wherein the filter pad contains a protein stabilizer or a buffer solution or a mixture thereof.

12. The biosensors as set forth in claims 1, wherein a reservoir formed in the lower cover, and connected via capillary with the hole of the lower cover.

13. The biosensor as set forth in claim 1, wherein the conjugated enzyme is selected from any reductase or oxidase enzymes.