Sensor element for determination of concentration of substances

• US 5,157,262 A
• Filed: 05/28/1991
• Issued: 10/20/1992
• Est. Priority Date: 04/23/1986
• Status: Expired due to Fees

• Current Assignee: Avl Medical Instruments AG (Roche Holding AG)
• Original Assignee: Avl Medical Instruments AG (Roche Holding AG)
• Inventors: Kroneis, Herbert, Karpf, Hellfried, Wolfbeis, Otto S., List, Helmut, Leitner, Alfred, Marsoner, Hermann
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): HANIG, RICHARD E
• Application Number:
  US07/706,004
• Time in Patent Office: 511 Days
• Field of Search: 250/458.1, 250/459.1, 250/461.1, 422/56, 422/82.01
• US Class Current: 250/458.1
• CPC Class Codes: G01N 2021/174 either absorption-reflection or emission-fluorescence
• CPC Class Codes: G01N 2021/7786 Fluorescence
• CPC Class Codes: G01N 21/255 Details, e.g. use of specially adapted sources, lighting or optical systems
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/77 by observing the effect on a chemical indicator
• CPC Class Codes: G01N 21/81 Indicating humidity
• CPC Class Codes: G01N 2201/0621 Supply
• CPC Class Codes: G01N 2201/0622 Use of a compensation LED

Abstract

Due to the size of the devices used for the excitation and measuring of light, conventional sensor elements for optically determining the concentrations of substances contained in gaseous and liquid samples, featuring an indicator layer with one or more indicator substances, are not well suited for use with microanalysis equipment, nor are they easy to mass-produce. These disadvantages are eliminated by integrating on the carrier layer (1) at least one photosensitive element (3) and its electric contact leads in planar arrangement, and by establishing optical contact between the indicator substance (7, 7'"'"') of the indicator layer (6) stimulated by the excitation radiation (11), and the photosensitive elements (3).

Claims

1. An electro-optical sensor element for determining the concentration of substances contained in gaseous and liquid samples, comprising

a carrier layer,

an indicator layer which has been produced by microelectronic and photolithographic techniques and which comprises at least one indicator substance having optical properties, wherein at least one of said optical properties of said indicator substance will change upon interaction with said substances contained in said gaseous and liquid samples, depending on the concentrations of said substances in said gaseous and liquid samples,

a transparent coupling layer located between said carrier layer and said indicator layer,

a thin film arrangement of a plurality of light-emitting sources located between said carrier layer and said transparent coupling layer, said light-emitting sources being in optical contact with said indicator layer and having electrical leads connected thereto, and

a thin film arrangement of a plurality of photosensitive elements located between said carrier layer and said transparent coupling layer, said photosensitive elements being in optical contact with said indicator layer and having electrical leads connected thereto.

2. An electro-optical sensor element according to claim 1, wherein said light-emitting sources and said photosensitive elements are located in adjoining first and second microzones of said sensor element.

3. An electro-optical sensor element according to claim 2, wherein a semiconductor structure constituting said light-emitting sources and said electric contacts of said light-emitting sources is integrated on a separate substrate which is deposited in said first microzones of said sensor element carrying said light-emitting sources.

4. An electro-optical sensor element according to claim 2, wherein said first and second microzones are arranged in a chessboard-type pattern, and are provided alternately with said light-emitting sources and said photosensitive elements.

5. An electro-optical sensor element according to claim 2, wherein said first and second microzones are arranged in honeycomb fashion, each of said light-emitting sources being surrounded by two or more equidistant photosensitive elements, and wherein said photosensitive elements are coated with different filter materials.

6. An electro-optical sensor element according to claim 2, wherein each of said light-emitting sources is surrounded by one of said photosensitive elements of an annular structure.

7. An electro-optical sensor element according to claim 2, wherein said light-emitting sources and said photosensitive elements are provided in different thin film arrangements parallel to each other, said light-emitting sources forming a continuous luminescent layer covering said carrier layer, and wherein a semiconductor structure constituting said photosensitive elements is integrated on a substrate covering said luminescent layer and wherein said substrate carrying said photosensitive elements is provided with zones permitting optical contact between said luminescent layer and said indicator layer.

8. An electro-optical sensor element according to claim 7, wherein an optical filter layer is provided between said luminescent layer and said substrate carrying said photosensitive elements.

9. An electro-optical sensor element according to claim 7, wherein said zones permitting optical contact between said luminescent layer and said indicator layer are provided with a filter layer.

10. An electro-optical sensor element according to claim 1, wherein said coupling layer contains a diffraction structure directing excitation radiation from said light-emitting sources into areas of said indicator layer facing said photosensitive elements.

11. An electro-optical sensor element according to claim 1, wherein said photosensitive elements and said light-emitting sources are additionally coated with an optical filter layer.

12. An electro-optical sensor element according to claim 1, wherein an interference filter is situated between said transparent coupling layer and said indicator layer, which has different transmission coefficients for an excitation radiation emitted by said light-emitting sources and fluorescent radiation emitted by said indicator substance, depending on given angles of incidence.

13. An electro-optical sensor element according to claim 1, wherein indicator molecules of said indicator substance are chemically bonded to said transparent coupling layer.

14. An electro-optical sensor element according to claim 1, wherein electronic circuits are integrated on said carrier layer, said circuits being designed for controlling the brightness of an excitation radiation generated by said light-emitting sources and for amplifying electric signals produced by said photosensitive elements.