Electrochemical sensors membrane

• US 5,711,868 A
• Filed: 09/15/1995
• Issued: 01/27/1998
• Est. Priority Date: 06/27/1994
• Status: Expired due to Term

• Current Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Original Assignee: Chiron Corporation (Bayer AG)
• Inventors: Flaherty, James E., D'Orazio, Paul A., McCaffrey, Robert R., Dalzell, Bonnie C., Maley, Thomas C., Edelman, Peter G., Mason, Richard W.
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US08/508,275
• Time in Patent Office: 865 Days
• Field of Search: 204/415, 204/296, 205/782.5, 205/783
• US Class Current: 205/782.5
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49204 Contact or terminal manufacturing
• CPC Class Codes: Y10T 29/53261 Means to align and advance work part
• CPC Class Codes: Y10T 29/53265 with work-holder for assembly

Abstract

A solid state, multi-use electrochemical sensor having an electrically nonconductive substrate, a working electrode, and a semi-permeable membrane covering the working electrode. The working electrode includes an electrically conductive material adhered to a portion of the substrate. A first portion of the conductive material is covered with an electrically insulating dielectric coating, and a second portion of the conductive material is covered with an active layer. The active layer includes a catalytically active quantity of an enzyme carried by platinized carbon powder particles, which are distributed throughout the active layer. A sensor package for incorporating a sensor is provided.

Claims

1. A sensor comprising a semi-permeable membrane which permits passage of water, oxygen and at least one selective analyte and which has the ability to absorb water, for contacting a test sample, said membrane having a high boiling point, water soluble, hydrophilic polymer liquid anti-drying agent which is added after said membrane has been formed so that the sensor storage life is prolonged and wet-up is facilitated.

2. The sensor of claim 1, wherein said anti-drying agent comprises a material selected from the group consisting of surfactants having a molecular weight of at least about 300 and polyethylene glycols having molecular weights of between about 200 and 600.

3. A sensor in accordance with claim 2 wherein said anti-drying agent is a polyethylene glycol.

4. A sensor in accordance with claim 3 wherein said membrane is an anionically stabilized, water based hydroxyl end blocked polydimethyl siloxane elastomer containing at least 10% of weight of silica.

5. A sensor in accordance with claim 1 wherein said membrane is a polydimethyl siloxane.

6. A sensor in accordance with claim 1 wherein said membrane is a polydimethyl siloxane elastomer containing at least 10% by weight of silica.

7. A method for prolonging the storage life or wet-up of an electrochemical sensor including a semi-permeable membrane, said method comprising treating the semi-permeable membrane after formation with a high boiling point, water soluble, hydrophilic polymer liquid anti-drying agent selected from the group consisting of surfactants having a molecular weight of at least about 300 and polyethylene glycols.