Thick-film conductivity enzyme electrodes in a vertical stack as biosensor

• US 5,770,439 A
• Filed: 09/28/1992
• Issued: 06/23/1998
• Est. Priority Date: 09/28/1991
• Status: Expired due to Fees

• Current Assignee: Gesellschaft Fur Biotechnologische Forschung mbH, Siegert GmbH
• Original Assignee: Gesellschaft Fur Biotechnologische Forschung mbH
• Inventors: Bechtold, Franz, Drewes, Wiebke, Bilitewski, Ursula
• Primary Examiner(s): Naff, David M.
• Application Number:
  US07/952,044
• Time in Patent Office: 2,094 Days
• Field of Search: 435/174, 435/176, 435/177, 435/180, 435/817, 204/403
• US Class Current: 435/287.1
• CPC Class Codes: C12Q 1/002 Electrode membranes
• CPC Class Codes: C12Q 1/003 Functionalisation
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

A biosensor is produced by depositing thick film pastes by screen-printing on a substrate to produce thick-film conductivity electrodes, and immobilizing enzymes on the electrodes. In specific embodiments, the substrate is an unfired ceramic, a fired ceramic or a plastic, the paste is a noble metal paste, enzyme immobilization is with a bifunctional reagent, a plurality of different enzymes are immobilized on different electrodes, and/or the electrodes are printed as parallel lines or in the image of a comb or concentric circles. A multi-dimensional biosensor is prepared by forming thick film paste electrodes containing an immobilized enzyme on a plurality of separate substrates, disposing the separate substrates one on top of the other in a vertical stack, pressing the stacked substrates together and curing the paste.

Claims

1. A method for the production of a conductivity biosensor which comprises;

a plurality of electrodes on a plurality of substrates; and

an enzyme immobilized on the electrodes;

comprising the steps;

A. screen printing on a plurality of separate substrates a conductive electrode forming thick film paste, whereby the electrode is formed on the substrate;

B. immobilizing an enzyme on the electrode;

C. disposing the separate substrates bearing printed conductive electrodes and immobilized enzyme in a vertical stack, one on top of the other;

D. pressing the stacked substrates together; and

E. curing the printed paste, whereby a multi-dimensional biosensor is produced.

2. The method of claim 1 wherein the substrate is an unfired ceramic.

3. The method of claim 1 wherein the substrate is selected from the group consisting of a fired ceramic and a plastic.

4. The method of claim 1 wherein the paste is a noble metal paste.

5. The method of claim 1 wherein the enzyme is one which catalyzes a reaction wherein ions are released.

6. The method of claim 1 wherein a plurality of different enzymes are immobilized on different electrodes.

7. The method of claim 1 wherein immobilization is by cross-linking with a bifunctional reagent.

8. A conductivity biosensor, which comprises;

A. a plurality of substrate layers pressed together in a vertical stack;

B. each substrate layer bearing a conductive electrode formed thereon by screen printing a thick film paste; and

C. each electrode having immobilized thereon an enzyme for sensing an analyte.

9. The biosensor of claim 8 wherein the electrodes are positioned in different geometric forms.

10. The biosensor of claim 8 wherein the electrodes are printed as parallel lines.

11. The biosensor of claim 8 wherein the electrodes are printed in the image of a comb.

12. The biosensor of claim 8 wherein the electrodes are printed in the image of concentric circles.

13. The biosensor of claim 8 wherein immobilization is by cross-linking with a bifunctional reagent.

14. A conductivity biosensor for detecting the presence of a plurality of different analytes, which comprises;

A. a plurality of substrate layers pressed together in a vertical stack;

B. each substrate layer bearing on the surface thereof, a conductive electrode formed by a screen-printing of a thick-film paste of electrode forming composition;

C. each electrode having immobilized thereon an enzyme for sensing at least one of said analytes;

D. at least two of the electrodes having enzymes for detecting different analytes; and

E. conductor means attached to the electrodes for supplying electrical current thereto.