Surface Plasmon Resonance Spectrometer with an Actuator Driven Angle Scanning Mechanism

• US 20070222996A1
• Filed: 11/21/2006
• Published: 09/27/2007
• Est. Priority Date: 11/21/2005
• Status: Active Grant

• Current Assignee: Suzhou Puxin Life Science & Technology Limited
• Original Assignee: Lumera Corp. (Renesas Electronics Corporation)
• Inventors: Cong, Shuxin, Guan, Hann-Wen
• Granted Patent: US 7,889,347 B2
• Time in Patent Office: Days
• US Class Current: 356/445
• CPC Class Codes: G01N 21/553 and using surface plasmons fluorescence excitation G01N21/648; enhanced Raman G01N21/658

Abstract

Instruments and methods relating to surface plasmon imaging are described. An instrument comprises a semi-circular rail and a driving mechanism. The driving mechanism is attached to a light source mount and a detector mount, and both the light source mount and the detector mount are attached to the semi-circular rail with connectors. Each connector allows the light source mount and detector mount to slide along the rail. The synchronous movement of the light source mount and the detector mount changes the angle of incidence of a light beam from the light source with respect to the plane of the sample surface on the sample stage.

Claims

1. An instrument, comprising:

a) a semicircular rail;

b) a sample stage for receiving a sample, the sample stage forming a plane;

c) a light source mount on the rail;

d) a light source on the light source mount;

e) a detector mount on the rail; and

f) a detector on the detector mount, wherein the light source mount and the detector mount move synchronously along the rail in opposite directions.

2. The instrument of claim 1, further comprising a driving mechanism, wherein the driving mechanism comprises:

a) a driving bridge having a first pivot point and a second pivot point;

b) a first swing arm with a first end and a second end, the first end being connected to the driving bridge through the first pivot point;

c) and a second swing arm with a first end and a second end, the first end being connected to the driving bridge through the second pivot point, wherein the second end of the first swing arm is connected to a pivot point on the light source mount and the second end of the second swing arm is connected to a pivot point on the detector mount.

3. The instrument of claim 2, wherein the driving bridge is moved by a linear actuator having a path that is substantially perpendicular to the plane of the sample stage.

4. The instrument of claim 3, wherein the light source comprises a laser that generates a laser beam.

5. The instrument of claim 4, wherein the laser beam is scanned across the surface of the sample with a microelectromechanical mirror.

6. The instrument of claim 4, wherein the laser operates in a wavelength range from about 360 nm to about 2000 nm.

7. The instrument of claim 6, wherein the detector is a CCD camera.

8. The instrument of claim 7, further comprising a prism assembly mounted beneath the sample stage.

9. The instrument of claim 8, wherein the first swing arm and the second swing arm are curved.

10. The instrument of claim 9, wherein the each of the light source mount and the detector mount rests on the semicircular rail through at least two wheels.

11. The instrument of claim 10, wherein the light source mount further includes a polarizer.

12. The instrument of claim 11, wherein the light source mount further includes a routing mirror assembly.

13. The instrument of claim 10, wherein the detector mount further includes a telescope.

14. A method, comprising:

1) providing a light source, a detector, and a sample, wherein the light source generates a light beam;

     2) directing the light beam at the sample to form an angle of incidence between the light beam and the sample; and

     3) moving the light source and the detector synchronously by sliding the light source and detector in opposite directions along a semicircular rail, thereby modifying the angle of incidence.

15. The method of claim 14, wherein the sample is a microarray comprising a gold substrate and the light beam generates surface plasmon resonance at the gold surface.

16. The method of claim 15, wherein the detector is a CCD camera having pixels.

17. The method of claim 16, wherein at least one linear actuator controls the sliding of the light source and the detector along the semicircular rail.

18. The method of claim 17, wherein the light source is a laser.

19. The method of claim 18, wherein the light beam is scanned across the surface of the sample at a selected rate.

20. The method of claim 19, wherein the rate at which the light source and the detector slide along the rail is slower than the frequency of the scan rate such that sample is scanned at least once before the angle of incidence is substantially modified.

21. The method of claim 20, wherein the laser operates in a wavelength range from about 360 nm to 2000 nm.

22. The method of claim 21, wherein a) the light source is mounted on a light source mount;

b) the detector is mounted on a detector mount;

c) a first swing arm connects the light mount to an driving bridge;

d) a second swing arm connects the detector mount to the driving bridge, and e) one linear actuator moves the driving bridge in a path perpendicular to a plane where the sample resides.

23. The method of claim 22, further comprising:

a) scanning a region on the microarray to be used in an assay;

b) plotting the intensity of light at the detector against the magnitude of the displacement of the linear actuator to give a curve comprising a linear slope;

c) choosing a specific point on the linear slope;

d) moving the linear actuator to the displacement corresponding to the specific point to give a fixed angle of incidence; and

e) performing the assay at the fixed angle of incidence.

24. The method of claim 23, wherein the point is near the bottom of the linear slope.

25. The method claim 16, wherein one pixel corresponds to a single spot on the microarray to give a pixel-spot assignment, wherein the pixel-spot assignment does not change as the angle of incidence is modified.

26. The method of claim 16, wherein a) a group of pixels of the CCD camera corresponds to a single spot on the microarray, forming a pixel group-spot assignment, wherein the pixel group-spot assignment does not change as the angle of incidence is modified.