Method of making a platform for use in a sensor in a microfluidic device

• US 6,770,322 B1
• Filed: 03/02/2001
• Issued: 08/03/2004
• Est. Priority Date: 03/03/2000
• Status: Active Grant

• Current Assignee: YSI Incorporated (Xylem, Inc.)
• Original Assignee: YSI Incorporated (Xylem, Inc.)
• Inventors: Moles, Donald R.
• Primary Examiner(s): Beck, Shrive P.
• Assistant Examiner(s): Fletcher, III, William Phillip
• Application Number:
  US09/799,820
• Time in Patent Office: 1,250 Days
• Field of Search: 427/58, 427/96, 427/97, 427/123, 427/404, 427/409, 427/2.1, 427/2.11, 427/2.3, 427/230, 427/237, 427/307, 204/403.01, 204/403.06, 435/287.2
• US Class Current: 427/230
• CPC Class Codes: C12Q 1/001 Enzyme electrodes

Abstract

A method is provided for constructing a platform for use in a sensor in a microfluidic device. The method may include the steps of selecting a polymeric film, laser drilling at least one frustoconical pore in the film, depositing a layer of metal suitable for use as an electrode over a wall of the pore, and depositing a membrane capable of detecting an analyte in the pore over the metal layer. The method may also include the additional step of forming a diffusion limiting layer in the pore at an exit end of the pore before depositing the membrane capable of detecting an analyte.

Claims

1. A method of forming a platform for use in a microfluidic sensor comprising:

selecting a polymeric film;

laser drilling at least one frustoconical pore in said film such that said pore has a large diameter portion and a small diameter portion, said small diameter portion facing an analyte containing fluid when the microfluidic sensor is in use;

depositing a layer of metal suitable for use as an electrode over a wall of said pore; and

depositing a membrane capable of detecting an analyte in said pore over said metal layer.

2. The method of claim 1 wherein said polymeric film is a polyimide.

3. The method of claim 2 wherein said polyimide is a self-bonding polyimide.

4. The method of claim 1 wherein said pore wall has a taper angle less than 15 degrees.

5. The method of claim 1 further comprising depositing a layer of amorphous carbon over said wall of said pore prior to depositing said layer of metal.

6. The method of claim 5 further comprising the step of, after depositing said layer of amorphous carbon, depositing an adhesion layer over said wall of said pore prior to depositing said layer of metal suitable for use as an electrode.

7. The method of claim 1 wherein said metal is platinum.

8. The method of claim 1 further comprising depositing a diffusion limiting layer in said small diameter portion of said pore.

9. The method of claim 8 wherein said diffusion limiting layer is polyvinyl alcohol.

10. The method of claim 1 further comprising forming a diffusion limiting layer in said pore at an exit end of said small diameter portion of said pore before depositing a membrane capable of detecting an analyte in said pore.