Planar-Resonator Based Optical Chemo- And Biosensor

• US 20070196043A1
• Filed: 05/05/2005
• Published: 08/23/2007
• Est. Priority Date: 05/11/2004
• Status: Active Grant

• Current Assignee: Tel Aviv University Future Technology Development L.P. (Tel Aviv University)
• Original Assignee: Tel Aviv University Future Technology Development L.P. (Tel Aviv University)
• Inventors: Nathan, Menachem, Ruschin, Shlomo, Peled, Asher, Zohar, Tali
• Granted Patent: US 7,447,391 B2
• Time in Patent Office: Days
• US Class Current: 385/12
• CPC Class Codes: G01N 21/774 the reagent being on a grating or periodic structure
• CPC Class Codes: G01N 21/7746 the waveguide coupled to a cavity resonator
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/124 Geodesic lenses or integrated gratings

Abstract

A biological or chemical optical sensing device comprises at least one planar micro-resonator structure included in a light emitting waveguide, and at least one biological or chemical probe bound to at least a part of the micro-resonator structure, the probe operative to bind specifically and selectively to a respective target substance, whereby the specific and selective binding results in a parameter change in light emitted from the waveguide. In one embodiment, the micro-resonator is linear. In some embodiments, the sensing device is active, the waveguide including at least one photoluminescent material operative to be remotely pumped by a remote optical source, and the parameter change, which may include a spectral change or a quality-factor change, may be remotely read by an optical reader.

Claims

1. A sensor comprising:

a. a substrate having a first refractive index; and

b. a planar waveguide formed on the substrate and having a second refractive index larger than the first refractive index, the waveguide comprising at least one micro-resonator structure on a waveguide surface opposite to the substrate, the micro-resonator structure operative to output a light signal that includes a spectral response to an interaction between a target substance and the micro-resonator.

2. The sensor of claim 1, wherein the micro-resonator includes a central section bound by two reflecting sections.

3. The sensor of claim 2, wherein each reflecting section includes a distributed Bragg reflector (DBR).

4. The sensor of claim 2, wherein the waveguide includes a sol-gel waveguide, the sensor further comprising:

c. at least one probe selected from the group consisting of at least one biological target binding material and at least one chemical target binding material, the probe fixated to at least a part of the micro-resonator structure.

5. The sensor of claim 2, wherein the micro-resonator structure is linear.

6. The sensor of claim 3, wherein the DBRs are identical.

7. The sensor of claim 4, wherein at least a part of the sol-gel waveguide includes at least one light emitting material that produces the light signal.

8. The sensor of claim 7, wherein the light emitting material includes a photoluminescent (PL) material.

9. The sensor of claim 4, wherein the sol-gel is selected from the group consisting of SiO₂, TiO₂, SiO₂/TiO₂ Ta₂O₃ and a mixture thereof.

10. The sensor of claim 3, wherein the DBRs include corrugations formed in the waveguide.

11. The sensor of claim 1, wherein the micro-resonator structure is linear and includes two reflecting sections bounding a central section, the reflecting sections including periodic perturbations formed on the waveguide, and wherein the waveguide includes a sol-gel waveguide, the sensor further comprising:

c. at least one probe selected from the group consisting of at least one biological target binding material and at least one chemical target binding material, the probe fixated to at least a part of the micro-resonator structure.

12. The sensor of claim 4, wherein the micro-resonator structure includes sections at least partially covered by a thin layer of a material different from the sol-gel.

13. The sensor of claim 12, wherein the material different from the sol-gel includes at least one metal.

14. The sensor of claim 13, wherein the at least one metal includes gold.

15. The sensor of claim 11, wherein the periodic perturbations are formed on the waveguide using a soft lithography process.

16. The sensor of claim 11, wherein the periodic perturbations include a material selected from the group consisting of the probe and at least one metal.

17. A sensing device comprising:

a. at least one linear planar micro-resonator structure included in a light emitting waveguide; and

b. at least one probe material bound to at least part of at least one micro-resonator structure, the probe material operative to bind specifically and selectively to a respective target substance, the specific and selective binding resulting in a parameter change in light emitted from the waveguide.

18. The sensing device of claim 17, wherein each linear planar micro-resonator structure includes a central region bound by two distributed Bragg reflectors (DBRs), the DBRs having corrugation tops and bottoms, the micro-resonator having at least one transverse mode.

19. The sensing device of claim 18, wherein the light emitting waveguide includes a sol-gel material doped with a photoluminescent (PL) material, whereby the sensing device is active.

20. The sensing device of claim 18, wherein the waveguide includes a sol-gel material, whereby the sensing device is passive.

21. The sensing device of claim 19, wherein the parameter change includes a measurable quality factor (Q) change.

22. The sensing device of claim 19, wherein the parameter change includes a measurable spectral change.

23. The sensing device of claim 22, wherein the spectral change includes a wavelength shift.

24. The sensing device of claim 20, wherein the parameter change includes a measurable quality factor (Q) change.

25. The sensing device of claim 19, wherein the sol-gel is selected from the group consisting of SiO₂, TiO₂, SiO₂/TiO₂, Ta₂O₃ and a mixture thereof.

26. The sensing device of claim 20, wherein the sol-gel is selected from the group consisting of SiO₂, TiO₂ SiO₂/TiO₂, Ta₂O₃ and a mixture thereof.

27. The sensing device of claim 18, wherein at least part of at least one micro-resonator structure includes a part selected from the group consisting of all the DBR corrugation tops, all the DBR corrugation bottoms, part of the corrugation tops and part of the corrugation bottoms.

28. The sensing device of claim 19, further comprising at least one surface plasmon resonance (SPR) element coupled to the micro-resonator structure, wherein the parameter change includes a change in a resonant wavelength of the emitted light.

29. The sensing device of claim 18, wherein the at least one transverse mode includes a plurality of N transverse modes, the device further comprising a plurality of longitudinal in-plane corrugations perpendicular to the DBR corrugations and operative to reduce the plurality to at least N−

1.

30. The sensing device of claim 17, wherein the at least one probe material is selected from the group consisting of at least one biological target binding material and at least one chemical target binding material

31. An optical sensing method for sensing remotely an interaction between a probe and a target substance, comprising the steps of:

providing at least one planar micro-resonator coupled to a light emitting waveguide, at least one of the micro-resonators having at least one probe bound to at least a micro-resonator surface part;

promoting a specific and selective binding between the at least one probe and the target substance;

remotely pumping the waveguide, thereby causing a parameter change in light emitted therefrom though at least part of the micro-resonator; and

remotely reading the parameter change.

32. The method of claim 31, wherein the step of providing at least one planar micro-resonator includes providing a linear planar micro-resonator.

33. The method of claim 31, wherein the step of reading the parameter change includes reading a spectral change.

34. The sensing device of claim 33, wherein the step of reading a spectral change includes reading a wavelength shift.

35. The method of claim 31, wherein the step of reading a parameter change includes reading a quality factor (Q) change.

36. The method of claim 35, wherein the step of reading a Q change includes reading a change selected from the group consisting of an emission spectral bandwidth change and an emission relaxation time change.

37. The method of claim 32, wherein the step of providing at least one linear planar micro-resonator includes providing at least two micro-resonators, at least one micro-resonator having at least one probe bound to at least a micro-resonator part and at least another micro-resonator being probe-free, and wherein the step of remotely reading the parameter change includes reading the parameter change differentially.

38. The method of claim 31, wherein the at least one probe is selected from the group consisting of at least one biological target binding material and at least one chemical target binding material