Solid-state detector and optical system for microchip analyzers

• US 20030222223A1
• Filed: 10/10/2002
• Published: 12/04/2003
• Est. Priority Date: 06/03/2002
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California), Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Street, Robert A., Kamei, Toshihiro, Mathies, Richard A., Scherer, James R.
• Granted Patent: US 6,867,420 B2
• Time in Patent Office: Days
• US Class Current: 250/458.1
• CPC Class Codes: G01J 2003/104 Monochromatic plural sources
• CPC Class Codes: G01J 2003/2806 Array and filter array
• CPC Class Codes: G01N 2021/6478 Special lenses
• CPC Class Codes: G01N 21/255 Details, e.g. use of specially adapted sources, lighting or optical systems
• CPC Class Codes: G01N 21/6454 using an integrated detector array

Abstract

A miniaturized optical excitation and detector system is described for detecting fluorescently labeled analytes in electrophoretic microchips and microarrays. The system uses miniature integrated components, light collection, optical fluorescence filtering, and an amorphous a-Si:H detector for detection. The collection of light is accomplished with proximity gathering and/or a micro-lens system. Optical filtering is accomplished by integrated optical filters. Detection is accomplished utilizing a-Si:H detectors.

Claims

1. A detector system for detecting light emitted at a first wavelength by fluorophores responsive to excitation light at a second wavelength comprising an integrated photodetector and an optical filter configured to reject light at the second wavelength and pass light emitted at the first wavelength to the photodetector.

2. A detector system as in claim 1 in which the photodetector is an a-Si:

H photodiode.

3. A detector system as in claim 1 or 2 including a lens for collimating the emitted light and directing it to the optical filter.

4. A detector system as in claim 3 in which the lens is integrated with the monolithic photodetector and filter.

5. A detector system as in claim 4 in which the lens is selected from convex lens, aspheric, half-ball, graded refractive index or diffractive.

6. A detector system as in claim 1 or 2 in which the filter and photodetector are partitioned and each partitioned filter passes light at a different wavelength than the other partitioned filters, whereby to detect light emitted by the fluorophores at different wavelengths.

7. A detector system as in claim 6 including a lens for directing the emitted light to the partitioned filter and photodetector.

8. A detector system as in claim 1, 2, 3 or 4 in which the filter and photodetector include an aperture, and the excitation light is directed through said aperture.

9. A detector system as in claim 8 including a VCSEL adjacent said photodetector for generating and directing light through said aperture.

17. A detector system as in claim 7 in which the lens is integrated with the integrated photodetector and optical filter.

31. A detector system as in claim 1 including spaced specific locations along each of said channels and integrated photodetectors and optical filters at said specific locations along said channels.

10. A detector system for detecting analyte which has been tagged with fluorophores which fluoresce and emit light of predetermined wavelengths comprising:

an integrated photodetector and an optical filter configured to pass light at said predetermined wavelength to said photodetector, and

a laser for directing a light beam of different wavelength onto said tagged analyte to cause emission of light at said predetermined wavelength.

11. A detector system as in claim 10 including a collimating lens for directing the emitted light onto said integrated photodetector and optical filter.

12. A detector system as in claim 10 or 11 in which the photodetector includes an aperture through which the light beam is projected.

13. A detector system as in claim 12 in which the laser comprises a VCSEL.

14. A detector system as in claim 12 in which the VCSEL is integrated with the integrated photodetector and filter.

15. A detector system as in claim 10, 11, 12 or 13 in which the photodetector is an a-Si:

H photodiode.

16. A detector system as in claim 14 in which the photodetector is an a-Si:

H photodiode.

18. A detector system for detecting light emitted by an excited fluorophore tagged to analytes which are separated along a channel comprising a plurality of photodetectors and optical filters spaced along said channel configured to pass the emitted light to the photodetector.

19. A detector system as in claim 18 in which the analyte is tagged with fluorophores which emit light at different wavelengths and the filters on different detectors are configured to pass emitted light of different wavelengths.

20. A detector system as in claim 18 in which the filter and photodetector of each integrated photodetector and optical filter are partitioned and each partitioned filter passes light at a different wavelength than the other partitioned filters, whereby to detect light emitted by the fluorophores at different wavelengths.

21. A detector system for detecting light emitted at a first wavelength responsive to excitation light at a second wavelength comprising a monolithic photodetector and filter, said filter configured to pass light emitted at the first wavelength to the photodetector and reject light at the second wavelength.

22. A detector system as in claim 21 including a monolithic lens serving to direct the emitted light to the filter and photodetector.

23. A detector system for detecting light emitted by fluorophores at a plurality of spaced locations comprising:

an integrated system including a plurality of photodetectors and optical filters each disposed to detect emitted light at a corresponding one of said spaced locations.

24. A detector system as in claim 23 in which each of said photodetectors and optical filters includes an aperture, and a laser projects light through said aperture to an associated fluorophore to cause it to emit light.

25. A detector system as in claim 24 in which each of said photodetectors and optical filters is partitioned and each partition receives light emitted by the fluorophore located at the corresponding location.

26. A detector system as in claim 25 in which the filter associated with each partition of a photodetector and filter passes light at a different wavelength.

27. A detector system as in claim 26 in which a lens is associated with each of said partitioned photodetectors and filters to direct light to the partitioned filters.

28. A detector system as in claims 23, 24 or 25 in which the plurality of photodetectors and filters is arranged in a one-dimensional array.

29. A detector system as in claims 23, 24 or 25 in which the plurality of photodetectors and filters is arranged in a two-dimensional array.

30. A detector system for detecting light emitted by fluorophores at a first wavelength in response to excitation by light at a second wavelength at specific locations in adjacent electrophoresis channels comprising:

an integrated system including a plurality of integrated photodetectors and optical filters configured to reject light at said second wavelength and pass emitted light at said first wavelength located at specific locations in said adjacent channels.

32. A detector system as in claim 30 or 31 including means for applying excitation light at said specific location to cause the fluorophores at each specific location to emit light.