Sensor elements with a tantalum- or niobium-containing base layer and methods of producing the same

Patent metadata

Field	Value
Publication number	US-2016305899-A1
Application number	US-201615195064-A
Country	US
Kind code	A1
Filing date	Jun 28, 2016
Priority date	Apr 29, 2011
Publication date	Oct 20, 2016
Grant date	—

Abstract

Sensor elements are disclosed for the electrochemically analyzing a body fluid, as well as methods of producing and using the same. The sensor elements include an electrically conductive layer structure applied to a non-conductive carrier substrate, where the layer structure includes a continuous base layer of tantalum, niobium or an alloy thereof, and a metallic cover layer formed on the base layer that covers the base layer either over the entire surface or in some regions. The metallic cover layer includes a more noble metal when compared to the base layer.

First claim

The invention claimed is:

1 . A sensor element for electrochemically analyzing a body fluid sample, the sensor element comprising:
an electrically insulating carrier substrate; and an electrically conductive layer structure deposited on a surface of the carrier substrate, wherein the electrically conductive layer structure comprises a continuous base layer of tantalum, niobium or an alloy thereof and a metallic cover layer formed on the base layer covering the base layer over an entire surface of the base layer or in some regions thereof, wherein the cover layer is a more noble metal when compared to the base layer, and wherein the electrically conductive layer structure includes an electrode arrangement to the which the body fluid sample can be applied.

2 . The sensor element of claim 1 , wherein the cover layer covers about 5% or more of the total area of the base layer.

3 . The sensor element of claim 1 , wherein the base layer has a greater layer thickness than the cover layer.

4 . The sensor element of claim 1 , wherein the base layer has an essentially constant layer thickness in the range of about 50 nm to about 200 nm.

5 . The sensor element of claim 1 , wherein the cover layer has a layer thickness of less than about 50 nm.

6 . The sensor element of claim 1 , wherein the cover layer has a layer thickness of less than about 20 nm.

7 . The sensor element of claim 1 , wherein the base layer includes a bonding agent for the cover layer, and wherein the bonding agent has a layer thickness of at least about 0.5 nm and less than about 20 nm.

8 . The sensor element of claim 1 , wherein the base layer is entirely tantalum.

9 . The sensor element of claim 1 , wherein the cover layer is a noble metal selected from the group consisting of gold, palladium, platinum and alloys thereof.

10 . The sensor element of claim 9 , wherein the noble metal is gold.

11 . The sensor element of claim 1 , wherein the electrode arrangement, and where appropriate, a region of contact to an electrical connection of the electrode arrangement are formed from metals in two layers.

12 . The sensor element of claim 1 , further comprising a reagent system for electrochemically detecting an analyte in the sample, wherein the reagent system is arranged in a region of the electrode arrangement.

13 . The sensor element of claim 12 , wherein the reagent system is configured for glucose, lactate or prothrombin time testing.

14 . A method of producing an electrochemical sensor element, the method comprising the steps of:
depositing an electrically conducting layer structure on an electrically insulating carrier substrate, wherein the electrically conducing layer structure is formed from a continuous base layer of tantalum, niobium or an alloy thereof and at least in some areas of a cover layer formed on the base layer of a more noble metal when compared to the base layer.

15 . The method of claim 14 , wherein the base layer is firstly applied to the carrier substrate and the cover layer is secondly applied to the base layer, each by a coating process.

16 . The method of claim 14 , wherein the base layer and the cover layer are formed by sputter deposition.

17 . The method of claim 14 , wherein the base layer and the cover layer are successively sputtered on in a vacuum chamber without interrupting a vacuum.

18 . The method of claim 14 , wherein the cover layer is applied to the base layer through a mask or aperture in a strip shape.

19 . The method of claim 14 , wherein the base layer and the cover layer are geometrically structured by removing material from sections by laser ablation.

20 . The method of claim 14 , wherein the base layer is tantalum and the cover layer is gold.

Assignees

• Roche Diabetes Care Inc

Inventors

• Harttig Herbert

Classifications

• C23C14/165

  by cathodic sputtering · CPC title

• C23C14/34

  Sputtering · CPC title

• C23C14/5873

  Removal of material · CPC title

• C23C14/042

  using masks · CPC title

• G01N27/3272 Primary

  Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels (optical biosensors G01N33/52) · CPC title