Sensor platform and method for the parallel detection of a plurality of analytes using evanescently excited luminescence

• US 6,289,144 B1
• Filed: 01/19/2000
• Issued: 09/11/2001
• Est. Priority Date: 05/12/1995
• Status: Expired due to Term

• Current Assignee: Novartis Ag
• Original Assignee: Novartis Ag
• Inventors: Pawlak, Michael, Duveneck, Gert Ludwig, Budach, Wolfgang, Pieles, Uwe, Neuschäfer, Dieter
• Primary Examiner(s): Bovernick, Rodney
• Assistant Examiner(s): KIM, ELLEN E
• Application Number:
  US09/487,560
• Time in Patent Office: 601 Days
• Field of Search: 385/12, 385/37, 385/129-132, 385/4, 385/8, 385/14, 385/31, 422/82.11
• US Class Current: 385/12
• CPC Class Codes: G01N 2021/0346 Capillary cells; Microcells
• CPC Class Codes: G01N 2021/7786 Fluorescence
• CPC Class Codes: G01N 2021/7793 Sensor comprising plural indicators
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/6452 Individual samples arranged in a regular 2D-array, e.g. multiwell plates
• CPC Class Codes: G01N 21/648 using evanescent coupling or surface plasmon coupling for the excitation of fluorescence
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B

Abstract

The invention relates to a sensor platform based on at least two planar, separate, inorganic dielectric waveguiding regions on a common substrate and to a method for the parallel evanescent excitation and detection of the luminescence of identical or different analytes. The invention relates also to a modified sensor platform that consists of the sensor platform having the planar, separate, inorganic dielectric waveguiding regions and one or more organic phases immobilised thereon. A further subject of the invention is the use of the sensor platform or of the modified sensor platform in a luminescence detection method for quantitative affinity sensing and for the selective quantitative determination of luminescent constituents of optically opaque solutions.

Claims

1. A sensor platform comprising:

a continuous substrate; and

a transparent, planar, inorganic, dielectric waveguiding layer provided on said continuous substrate;

wherein said waveguiding layer includes a plurality of waveguiding regions, and at least one dividing portion divides said waveguiding layer into said plurality of waveguiding regions;

wherein said at least one dividing portion has an effective refractive index lower than that of said waveguiding regions or has a material on its surface that absorbs coupled-in light;

wherein said waveguiding regions are provided with one coupling-in grating each or with a common coupling-in grating for coupling-in of light to said waveguiding regions in such a manner that the direction of propagation of a wave vector of the light is maintained after the coupling-in;

wherein said plurality of waveguiding regions are formed of the same material;

wherein said plurality of waveguiding regions are arranged so as to permit light coupled-in to said waveguiding regions to cause evanescent excitation of luminescence or a change of luminescence at each of said plurality of waveguiding regions; and

wherein, on the surfaces of said waveguiding regions, one or more specific binding partners are immobilized as chemical or biochemical recognition elements for one or more identical or different analytes.

2. A sensor platform of claim 1, wherein

said waveguiding regions are provided with one coupling-out grating each or with a common coupling-out grating.

3. A sensor platform of claim 1, wherein

said waveguiding layer is non-polymeric.

4. A sensor platform of claim 1, wherein

said waveguiding regions are spaced apart from one another.

5. A sensor platform of claim 1, wherein the individual waveguiding regions are arranged to form multiple detection regions.

6. A sensor platform according to claim 5, wherein the individual multiple detection regions are arranged in the form of a rectangular chessboard pattern or in the manner of individual images in a film strip.

7. A modified sensor platform according to claim 1, wherein the specific binding partners on the surface of each waveguiding region are physically separate from one another.

8. A sensor platform according to claim 1, wherein the specific binding partners are antibodies for antigens, binding proteins, such as protein A and G, for immunoglobulins, biological and chemical receptors for ligands, chelators for histidine-tag components, for example histidin-labelled proteins, oligonucleotides and single strands of RNA or DNA for their complementary strands, avidin for biotin, enzymes for enzyme substrates, enzyme cofactors or inhibitors, or lectins for carbohydrates.

9. A sensor platform according to claim 1, wherein an adhesion-promoting layer is located between the waveguiding regions and the immobilized specific binding partners.

10. A sensor platform according to claim 1, wherein the waveguiding regions are arranged in the form of separate strips, rectangles, circles, ellipses or chessboard patterns.

11. A sensor platform according to claim 1, wherein the division into a plurality of waveguiding regions is achieved by means of a change in the effective refractive index between the waveguiding regions and the adjacent material, the difference in effective refractive index being greater than 0.2 units.

12. A sensor platform according to claim 1, wherein the division into a plurality of waveguiding regions is effected by means of an absorbing material on the surface of the waveguiding layer.

13. A sensor platform according to claim 12, wherein the absorbing material is an organic compound.

14. A sensor platform according to claim 12, wherein the absorbing material is a dyed or pigmented polymer.

15. A sensor platform according to claim 1, wherein the substrate is glass, quartz or a transparent thermoplastic plastics material.

16. A sensor platform according to claim 1, wherein the refractive index of the waveguiding regions is greater than 2.

17. A sensor platform according to claim 1, wherein the waveguiding regions are formed of a material containing TiO₂, ZnO, Nb₂O₅, Ta₂O₅, HfO₂ or ZrO₂.

18. A sensor platform according to claim 1, wherein the thickness of the waveguiding regions is from 40 to 300 nm.

19. A sensor platform according to claim 1, wherein the modulation depth of the gratings is from 3 to 60 nm.

20. A sensor platform according to claim 1, wherein the ratio of the modulation depth of the gratings to the thickness of the waveguiding regions is equal to or less than 0.2.

21. A sensor platform according to claim 1, wherein the grating period is from 200 to 1000 nm.

22. A sensor platform according to claim 1, joined with a fluidics disc to form a unit that comprises supply lines and cell spaces.

23. A method for the parallel determination of one or more luminescences using a sensor platform according to claim 1, which method comprises bringing one or more liquid samples into contact with one or more of said waveguiding regions on the sensor platform, coupling excitation light into the waveguiding regions, causing the coupled-in light to pass through the waveguiding regions, thus exciting in parallel in the evanescent field the luminescent substances in the one or more samples or the luminescent substances immobilized on the waveguiding regions and, using optoelectronic components, measuring the luminescences produced thereby.

24. A method according to claim 23, wherein the one or more samples are brought into contact with the waveguiding regions when stationary or are passed over them continuously, the circulation being open or closed.

25. A method according to claim 23, characterized in that in a throughflow system the binding or desorption of luminescence-labelled affinity partners in the evanescent field is followed in real time.

26. A method according to claim 23, wherein (a) either isotropically radiated, evanescently excited luminescences are detected, or (b) wherein evanescently excited luminescences backcoupled into the waveguiding layer are detected via a coupling-out grating or at an edge of the sensor platform, or (c) wherein both the isotropically radiated luminescence and the backcoupled luminescence are detected independently of one another but simultaneously.

27. A method according to claim 23, wherein absorption of the excitation light coupled-in to said waveguiding regions and luminescence at said waveguiding regions is determined simultaneously.

28. A method according to claim 23, wherein the luminescences are excited by various laser light sources of identical or different wavelength.

29. A method according to claim 23 for the quantitative determination of biochemical substances in affinity sensing.

30. A method according to claim 23, wherein the one or more liquid samples comprise egg yolk, blood, serum, plasma or urine, surface water, a soil or plant extract or a liquor from a biological or synthetic process.

31. A method according to claim 23, wherein the one or more liquid samples comprise antibodies or antigens, receptors or ligands, chelators or histidine-tag components, oligonucleotides, DNA or RNA strands, DNA or RNA analogues, enzymes, enzyme substrates, enzyme cofactors or inhibitors, lectins and carbohydrates.

32. A sensor platform of claim 1, wherein

said waveguiding regions are formed on said substrate in such a manner that said sensor platform provides for simultaneous detection of evanescently excited luminescence from one or more analytes.

33. A sensor platform of claim 1, wherein microparticles are attached on the surfaces of the waveguiding regions.

34. A sensor platform of claim 33, wherein said one or more specific binding partners are immobilized on said microparticles.